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Jupa R, Rosell JA, Pittermann J. Bark structure is coordinated with xylem hydraulic properties in branches of five Cupressaceae species. Plant Cell Environ 2024; 47:1439-1451. [PMID: 38234202 DOI: 10.1111/pce.14824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/27/2023] [Accepted: 01/08/2024] [Indexed: 01/19/2024]
Abstract
The properties of bark and xylem contribute to tree growth and survival under drought and other types of stress conditions. However, little is known about the functional coordination of the xylem and bark despite the influence of selection on both structures in response to drought. To this end, we examined relationships between proportions of bark components (i.e. thicknesses of tissues outside the vascular cambium) and xylem transport properties in juvenile branches of five Cupressaceae species, focusing on transport efficiency and safety from hydraulic failure via drought-induced embolism. Both xylem efficiency and safety were correlated with multiple bark traits, suggesting that xylem transport and bark properties are coordinated. Specifically, xylem transport efficiency was greater in species with thicker secondary phloem, greater phloem-to-xylem thickness ratio and phloem-to-xylem cell number ratio. In contrast, species with thicker bark, living cortex and dead bark tissues were more resistant to embolism. Thicker phellem layers were associated with lower embolism resistance. Results of this study point to an important connection between xylem transport efficiency and phloem characteristics, which are shaped by the activity of vascular cambium. The link between bark and embolism resistance affirms the importance of both tissues to drought tolerance.
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Affiliation(s)
- Radek Jupa
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, California, USA
| | - Julieta A Rosell
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Jarmila Pittermann
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, California, USA
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2
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Miller RNG. Investigating anatomical traits and molecular mechanisms involved in resistance to Pierce's disease. A commentary on 'Xylem-dwelling pathogen unaffected by local xylem vessel network properties in grapevines (Vitis spp.)'. Ann Bot 2024; 133:i-ii. [PMID: 38427777 PMCID: PMC11037480 DOI: 10.1093/aob/mcae020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
This article comments on:
Ana Clara Fanton, Martin Bouda and Craig Brodersen, Xylem-dwelling pathogen unaffected by local xylem vessel network properties in grapevines (Vitis spp.), Annals of Botany, Volume 133, Issue 4, 1 April 2024, Pages 521–532 https://doi.org/10.1093/aob/mcae016
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Fanton AC, Bouda M, Brodersen C. Xylem-dwelling pathogen unaffected by local xylem vessel network properties in grapevines (Vitis spp.). Ann Bot 2024; 133:521-532. [PMID: 38334466 PMCID: PMC11037485 DOI: 10.1093/aob/mcae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 02/07/2024] [Indexed: 02/10/2024]
Abstract
BACKGROUND AND AIMS Xylella fastidiosa (Xf) is the xylem-dwelling bacterium associated with Pierce's disease (PD), which causes mortality in agriculturally important species, such as grapevine (Vitis vinifera). The development of PD symptoms in grapevines depends on the ability of Xf to produce cell-wall-degrading enzymes to break up intervessel pit membranes and systematically spread through the xylem vessel network. Our objective here was to investigate whether PD resistance could be mechanistically linked to xylem vessel network local connectivity. METHODS We used high-resolution X-ray micro-computed tomography (microCT) imaging to identify and describe the type, area and spatial distribution of intervessel connections for six different grapevine genotypes from three genetic backgrounds, with varying resistance to PD (four PD resistant and two PD susceptible). KEY RESULTS Our results suggest that PD resistance is unlikely to derive from local xylem network connectivity. The intervessel pit area (Ai) varied from 0.07 ± 0.01 mm2 mm-3 in Lenoir to 0.17 ± 0.03 mm2 mm-3 in Blanc do Bois, both PD resistant. Intervessel contact fraction (Cp) was not statically significant, but the two PD-susceptible genotypes, Syrah (0.056 ± 0.015) and Chardonnay (0.041 ± 0.013), were among the most highly connected vessel networks. Neither Ai nor Cp explained differences in PD resistance among the six genotypes. Bayesian re-analysis of our data shows moderate evidence against the effects of the traits analysed: Ai (BF01 = 4.88), mean vessel density (4.86), relay diameter (4.30), relay density (3.31) and solitary vessel proportion (3.19). CONCLUSIONS Our results show that radial and tangential xylem network connectivity is highly conserved within the six different Vitis genotypes we sampled. The way that Xf traverses the vessel network may limit the importance of local network properties to its spread and may confer greater importance on host biochemical responses.
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Affiliation(s)
| | - Martin Bouda
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia
| | - Craig Brodersen
- School of the Environment, Yale University, New Haven, CT, USA
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Michalak KM, Wojciechowska N, Marzec-Schmidt K, Bagniewska-Zadworna A. Conserved autophagy and diverse cell wall composition: unifying features of vascular tissues in evolutionarily distinct plants. Ann Bot 2024; 133:559-572. [PMID: 38324309 PMCID: PMC11037490 DOI: 10.1093/aob/mcae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/02/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND AND AIMS The formation of multifunctional vascular tissues represents a significant advancement in plant evolution. Differentiation of conductive cells is specific, involving two main pathways, namely protoplast clearance and cell wall modification. In xylogenesis, autophagy is a crucial process for complete protoplast elimination in tracheary elements, whose cell wall also undergoes strong changes. Knowledge pertaining to living sieve elements, which lose most of their protoplast during phloemogenesis, remains limited. We hypothesized that autophagy plays a crucial role, not only in complete cytoplasmic clearance in xylem but also in partial degradation in phloem. Cell wall elaborations of mature sieve elements are not so extensive. These analyses performed on evolutionarily diverse model species potentially make it possible to understand phloemogenesis to an equal extent to xylogenesis. METHODS We investigated the distribution of ATG8 protein, which is an autophagy marker, and cell wall components in the roots of ferns, gymnosperms and angiosperms (monocots, dicot herbaceous plants and trees). Furthermore, we conducted a bioinformatic analysis of complete data on ATG8 isoforms for Ceratopteris richardii. KEY RESULTS The presence of ATG8 protein was confirmed in both tracheary elements and sieve elements; however, the composition of cell wall components varied considerably among vascular tissues in the selected plants. Arabinogalactan proteins and β-1,4-galactan were detected in the roots of all studied species, suggesting their potential importance in phloem formation or function. In contrast, no evolutionary pattern was observed for xyloglucan, arabinan or homogalacturonan. CONCLUSIONS Our findings indicate that the involvement of autophagy in plants is universal during the development of tracheary elements that are dead at maturity and sieve elements that remain alive. Given the conserved nature of autophagy and its function in protoplast degradation for uninterrupted flow, autophagy might have played a vital role in the development of increasingly complex biological organizations, including the formation of vascular tissues. However, different cell wall compositions of xylem and phloem in different species might indicate diverse functionality and potential for substance transport, which is crucial in plant evolution.
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Affiliation(s)
- Kornel M Michalak
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland
| | - Natalia Wojciechowska
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland
| | | | - Agnieszka Bagniewska-Zadworna
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland
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Dell'Acqua N, Gambetta GA, Delzon S, Ferrer N, Lamarque LJ, Saurin N, Theodore P, Delmas CEL. Mechanisms of grapevine resilience to a vascular disease: investigating stem radial growth, xylem development and physiological acclimation. Ann Bot 2024; 133:321-336. [PMID: 38066666 DOI: 10.1093/aob/mcad188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/07/2023] [Indexed: 04/11/2024]
Abstract
BACKGROUND AND AIMS Plant vascular diseases significantly impact crop yield worldwide. Esca is a vascular disease of grapevine found globally in vineyards which causes a loss of hydraulic conductance due to the occlusion of xylem vessels by tyloses. However, the integrated response of plant radial growth and physiology in maintaining xylem integrity in grapevine expressing esca symptoms remains poorly understood. METHODS We investigated the interplay between variation in stem diameter, xylem anatomy, plant physiological response and hydraulic traits in two widespread esca-susceptible cultivars, 'Sauvignon blanc' and 'Cabernet Sauvignon'. We used an original experimental design using naturally infected mature vines which were uprooted and transplanted into pots allowing for their study in a mini-lysimeter glasshouse phenotyping platform. KEY RESULTS Esca significantly altered the timing and sequence of stem growth periods in both cultivars, particularly the shrinkage phase following radial expansion. Symptomatic plants had a significantly higher density of occluded vessels and lower leaf and whole-plant gas exchange. Esca-symptomatic vines showed compensation mechanisms, producing numerous small functional xylem vessels later in development suggesting a maintenance of stem vascular cambium activity. Stabilization or late recovery of whole-plant stomatal conductance coincided with new healthy shoots at the top of the plant after esca symptoms plateaued. CONCLUSIONS Modified cropping practices, such as avoiding late-season topping, may enhance resilience in esca-symptomatic plants. These results highlight that integrating dendrometers, xylem anatomy and gas exchange provides insights into vascular pathogenesis and its effects on plant physiology.
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Affiliation(s)
- Ninon Dell'Acqua
- INRAE, Bordeaux Sciences Agro, ISVV, SAVE, F-33140, Villenave d'Ornon, France
| | - Gregory A Gambetta
- EGFV, Bordeaux-Sciences Agro, INRAE, Université de Bordeaux, ISVV, 210 chemin de Leysotte, 33882 Villenave d'Ornon, France
| | | | - Nathalie Ferrer
- INRAE, Bordeaux Sciences Agro, ISVV, SAVE, F-33140, Villenave d'Ornon, France
| | - Laurent J Lamarque
- Univ. Bordeaux, INRAE, BIOGECO, 33615 Pessac, France
- Département des Sciences de l'Environnement, Université du Québec à Trois-Rivières, Trois-Rivières, Canada
| | - Nicolas Saurin
- UE Pech Rouge, Univ Montpellier, INRAE, Gruissan, France
| | - Pauline Theodore
- INRAE, Bordeaux Sciences Agro, ISVV, SAVE, F-33140, Villenave d'Ornon, France
| | - Chloé E L Delmas
- INRAE, Bordeaux Sciences Agro, ISVV, SAVE, F-33140, Villenave d'Ornon, France
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Bozonnet C, Saudreau M, Badel E, Charrier G, Améglio T. On the mechanism for winter stem pressure build-up in walnut trees. Tree Physiol 2024; 44:tpae037. [PMID: 38531772 DOI: 10.1093/treephys/tpae037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/04/2024] [Accepted: 03/19/2024] [Indexed: 03/28/2024]
Abstract
Xylem embolism is a significant factor in tree mortality. Restoration of hydraulic conductivity after massive embolization of the vascular system requires the application of positive pressure to the vessels and/or the creation of new conductive elements. Some species generate positive pressure from the root system to propagate pressure in distal, aboveground organs in spring, whereas other species generate positive pressure locally at the stem level during winter. We provide a mechanistic explanation for winter stem pressure build-up in the walnut tree. We have developed a physical model that accounts for temperature fluctuations and phase transitions. This model is based on the exchange of water and sugars between living cells and vessels. Our computations demonstrate that vessel pressurization can be attributed to the transfer of water between vessels across the parenchyma rays, which is facilitated by a radial imbalance in sugar concentration. The ability to dispose of soluble sugars in living cells, and to transport them between living cells and up to the vessels, is identified as the main drivers of stem pressure build-up in the walnut tree.
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Affiliation(s)
- Cyril Bozonnet
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Marc Saudreau
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Eric Badel
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Guillaume Charrier
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Thierry Améglio
- Université Clermont Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
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7
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Tonet V, Brodribb T, Bourbia I. Variation in xylem vulnerability to cavitation shapes the photosynthetic legacy of drought. Plant Cell Environ 2024; 47:1160-1170. [PMID: 38108586 DOI: 10.1111/pce.14788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 11/08/2023] [Accepted: 12/01/2023] [Indexed: 12/19/2023]
Abstract
Increased drought conditions impact tree health, negatively disrupting plant water transport which, in turn, affects plant growth and survival. Persistent drought legacy effects have been documented in many diverse ecosystems, yet we still lack a mechanistic understanding of the physiological processes limiting tree recovery after drought. Tackling this question, we exposed saplings of a common Australian evergreen tree (Eucalyptus viminalis) to a cycle of drought and rewatering, seeking evidence for a link between the spread of xylem cavitation within the crown and the degree of photosynthetic recovery postdrought. Individual leaves experiencing >35% vein cavitation quickly died but this did not translate to a rapid overall canopy damage. Rather, whole canopies showed a gradual decline in mean postdrought gas exchange rates as water stress increased. This gradual loss of canopy function postdrought was due to a significant variation in cavitation vulnerability of leaves within canopies leading to diversity in the capacity of leaves within a single crown to recover function after drought. These results from the evergreen E. viminalis emphasise the importance of within-crown variation in xylem vulnerability as a central character regulating the dynamics of canopy death and the severity of drought legacy through time.
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Affiliation(s)
- Vanessa Tonet
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
- School of Forestry & Environmental Studies, Yale University, New Haven, Connecticut, USA
| | - Timothy Brodribb
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
| | - Ibrahim Bourbia
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
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8
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Aguirre NM, Ochoa ME, Holmlund HI, Palmeri GN, Lancaster ER, Gilderman GS, Taylor SR, Sauer KE, Borges AJ, Lamb AND, Jacques SB, Ewers FW, Davis SD. How megadrought causes extensive mortality in a deep-rooted shrub species normally resistant to drought-induced dieback: The role of a biotic mortality agent. Plant Cell Environ 2024; 47:1053-1069. [PMID: 38017668 DOI: 10.1111/pce.14768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 10/21/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023]
Abstract
Southern California experienced unprecedented megadrought between 2012 and 2018. During this time, Malosma laurina, a chaparral species normally resilient to single-year intense drought, developed extensive mortality exceeding 60% throughout low-elevation coastal populations of the Santa Monica Mountains. We assessed the physiological mechanisms by which the advent of megadrought predisposed M. laurina to extensive shoot dieback and whole-plant death. We found that hydraulic conductance of stem xylem (Ks, native ) was reduced seven to 11-fold in dieback adult and resprout branches, respectively. Staining of stem xylem vessels revealed that dieback plants experienced 68% solid-blockage, explaining the reduction in water transport. Following Koch's postulates, persistent isolation of a microorganism in stem xylem of dieback plants but not healthy controls indicated that the causative agent of xylem blockage was an opportunistic endophytic fungus, Botryosphaeria dothidea. We inoculated healthy M. laurina saplings with fungal isolates and compared hyphal elongation rates under well-watered, water-deficit, and carbon-deficit treatments. Relative to controls, we found that both water deficit and carbon-deficit increased hyphal extension rates and the incidence of shoot dieback.
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Affiliation(s)
- Natalie M Aguirre
- Ecology and Evolutionary Biology Program, Texas A&M University, College Station, Texas, USA
- Natural Science Division, Pepperdine University, Malibu, California, USA
| | - Marissa E Ochoa
- Natural Science Division, Pepperdine University, Malibu, California, USA
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, USA
| | - Helen I Holmlund
- Natural Science Division, Pepperdine University, Malibu, California, USA
| | | | - Emily R Lancaster
- Natural Science Division, Pepperdine University, Malibu, California, USA
- School of Marine Sciences, University of Maine, Orono, Maine, USA
| | - Gina S Gilderman
- Natural Science Division, Pepperdine University, Malibu, California, USA
| | - Shaquetta R Taylor
- Natural Science Division, Pepperdine University, Malibu, California, USA
| | - Kaitlyn E Sauer
- Natural Science Division, Pepperdine University, Malibu, California, USA
| | - Adriana J Borges
- Natural Science Division, Pepperdine University, Malibu, California, USA
| | - Avery N D Lamb
- Natural Science Division, Pepperdine University, Malibu, California, USA
- Nicholas School of the Environment, The Divinity School, Duke University, Durham, North Carolina, USA
| | - Sarah B Jacques
- Natural Science Division, Pepperdine University, Malibu, California, USA
- Department of Surgery, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Frank W Ewers
- Department of Biological Sciences, California State Polytechnic University, Pomona, California, USA
| | - Stephen D Davis
- Natural Science Division, Pepperdine University, Malibu, California, USA
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9
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Jain P, Huber AE, Rockwell FE, Sen S, Holbrook NM, Stroock AD. New approaches to dissect leaf hydraulics reveal large gradients in living tissues of tomato leaves. New Phytol 2024; 242:453-465. [PMID: 38413216 DOI: 10.1111/nph.19585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 01/22/2024] [Indexed: 02/29/2024]
Abstract
The water status of the living tissue in leaves is critical in determining plant function and global exchange of water and CO2. Despite significant advances in the past two decades, persistent questions remain about the tissue-specific origins of leaf hydraulic properties and their dependence on water status. We use a fluorescent nanoparticle reporter that provides water potential in the mesophyll apoplast adjacent to the epidermis of intact leaves to complement existing methods based on the Scholander Pressure Chamber (SPC). Working in tomato leaves, this approach provides access to the hydraulic conductance of the whole leaf, xylem, and outside-xylem tissues. These measurements show that, as stem water potential decreases, the water potential in the mesophyll apoplast can drop below that assessed with the SPC and can fall significantly below the turgor loss point of the leaf. We find that this drop in potential, dominated by the large loss (10-fold) of hydraulic conductance of the outside-xylem tissue, is not however strong enough to significantly limit transpiration. These observations highlight the need to reassess models of water transfer through the outside-xylem tissues, the potential importance of this tissue in regulating transpiration, and the power of new approaches for probing leaf hydraulics.
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Affiliation(s)
- Piyush Jain
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Annika E Huber
- Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Fulton E Rockwell
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Sabyasachi Sen
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Abraham D Stroock
- Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, 14853, USA
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10
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Jain P, Huber AE, Rockwell FE, Sen S, Holbrook NM, Stroock AD. Localized measurements of water potential reveal large loss of conductance in living tissues of maize leaves. Plant Physiol 2024; 194:2288-2300. [PMID: 38128552 PMCID: PMC10980393 DOI: 10.1093/plphys/kiad679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/25/2023] [Accepted: 11/30/2023] [Indexed: 12/23/2023]
Abstract
The water status of the living tissue in leaves between the xylem and stomata (outside xylem zone (OXZ) plays a critical role in plant function and global mass and energy balance but has remained largely inaccessible. We resolve the local water relations of OXZ tissue using a nanogel reporter of water potential (ψ), AquaDust, that enables an in situ, nondestructive measurement of both ψ of xylem and highly localized ψ at the terminus of transpiration in the OXZ. Working in maize (Zea mays L.), these localized measurements reveal gradients in the OXZ that are several folds larger than those based on conventional methods and values of ψ in the mesophyll apoplast well below the macroscopic turgor loss potential. We find a strong loss of hydraulic conductance in both the bundle sheath and the mesophyll with decreasing xylem potential but not with evaporative demand. Our measurements suggest the OXZ plays an active role in regulating the transpiration path, and our methods provide the means to study this phenomenon.
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Affiliation(s)
- Piyush Jain
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Annika E Huber
- Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Fulton E Rockwell
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Sabyasachi Sen
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Noel Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Abraham D Stroock
- Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
- School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853, USA
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11
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Power CC, Normand S, von Arx G, Elberling B, Corcoran D, Krog AB, Bouvin NK, Treier UA, Westergaard-Nielsen A, Liu Y, Prendin AL. No effect of snow on shrub xylem traits: Insights from a snow-manipulation experiment on Disko Island, Greenland. Sci Total Environ 2024; 916:169896. [PMID: 38185160 DOI: 10.1016/j.scitotenv.2024.169896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/18/2023] [Accepted: 01/02/2024] [Indexed: 01/09/2024]
Abstract
Widespread shrubification across the Arctic has been generally attributed to increasing air temperatures, but responses vary across species and sites. Wood structures related to the plant hydraulic architecture may respond to local environmental conditions and potentially impact shrub growth, but these relationships remain understudied. Using methods of dendroanatomy, we analysed shrub ring width (RW) and xylem anatomical traits of 80 individuals of Salix glauca L. and Betula nana L. at a snow manipulation experiment in Western Greenland. We assessed how their responses differed between treatments (increased versus ambient snow depth) and soil moisture regimes (wet and dry). Despite an increase in snow depth due to snow fences (28-39 %), neither RW nor anatomical traits in either species showed significant responses to this increase. In contrast, irrespective of the snow treatment, the xylem specific hydraulic conductivity (Ks) and earlywood vessel size (LA95) for the study period were larger in S. glauca (p < 0.1, p < 0.01) and B. nana (p < 0.01, p < 0.001) at the wet than the dry site, while both species had larger vessel groups at the dry than the wet site (p < 0.01). RW of B. nana was higher at the wet site (p < 0.01), but no differences were observed for S. glauca. Additionally, B. nana Ks and LA95 showed different trends over the study period, with decreases observed at the dry site (p < 0.001), while for other responses no difference was observed. Our results indicate that, taking into account ontogenetic and allometric trends, hydraulic related xylem traits of both species, along with B. nana growth, were influenced by soil moisture. These findings suggest that soil moisture regime, but not snow cover, may determine xylem responses to future climate change and thus add to the heterogeneity of Arctic shrub dynamics, though more long-term species- and site- specific studies are needed.
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Affiliation(s)
- Candice C Power
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark.
| | - Signe Normand
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Bo Elberling
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Derek Corcoran
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Amanda B Krog
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark
| | | | - Urs Albert Treier
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Andreas Westergaard-Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Yijing Liu
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Angela L Prendin
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; Department of Land Environment Agriculture and Forestry (TeSAF), University of Padova, Legnaro, Italy
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12
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Hoffmann WA, Sherry CDK, Donnelly TM. Stem heating results in hydraulic dysfunction in Symplocos tinctoria: implications for post-fire tree death. Tree Physiol 2024; 44:tpae023. [PMID: 38349803 DOI: 10.1093/treephys/tpae023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 02/07/2024] [Indexed: 02/15/2024]
Abstract
Fire-induced heating of stems can impair plant water transport by deforming xylem and increasing vulnerability to cavitation, but it is not clear whether these effects can result in tree death, or how quickly this may occur. In field experiments, we heated stems of Symplocos tinctoria (L.) L'Hér saplings to 90 °C using a thin-film resistive heater, and we monitored stomatal conductance, leaf water potential, sap flow and hydraulic conductivity until stem death. Sap flow and stomatal conductance declined quickly after heating, while whole-plant hydraulic conductance and leaf water potential remained high for the first week. In fact, leaf water potential increased during the first days after heating, indicating that stomatal closure was not initially caused by leaf water deficit induced by impaired water transport. After 1 week, leaf water potential and whole-plant conductance declined below unheated controls, while stomatal conductance and sap flow continued declining, approaching zero after 2 weeks. To better understand the cause of these declines, we directly measured hydraulic conductivity of heated stems. Stems underwent a progressive decline in conductivity after heating, and by the time that samples were severely wilted or desiccated, the heated portion of stems had little or no conductivity. Importantly, conductivity of heated stems was not recovered by flushing stems to remove embolisms, suggesting the existence of physical occlusions. Scanning electron micrographs did not reveal deformed cell walls, nor did it identify alternative causes of blockages. These results reveal that stem heating can result in xylem dysfunction and mortality, but neither response is immediate. Dysfunction was likely caused by wound responses rather than embolism, but improved understanding of the mechanisms of heat-induced hydraulic failure is needed.
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Affiliation(s)
- William A Hoffmann
- Department of Plant and Microbial Biology, 100 Derieux Place North Carolina State University, Raleigh, NC 27695, USA
| | - Catherine D K Sherry
- Department of Plant and Microbial Biology, 100 Derieux Place North Carolina State University, Raleigh, NC 27695, USA
| | - Tallis M Donnelly
- Department of Plant and Microbial Biology, 100 Derieux Place North Carolina State University, Raleigh, NC 27695, USA
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13
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Zhang X, Ma S, Hu H, Li F, Bao W, Huang L. A trade-off between leaf hydraulic efficiency and safety across three xerophytic species in response to increased rock fragment content. Tree Physiol 2024; 44:tpae010. [PMID: 38245807 PMCID: PMC10918055 DOI: 10.1093/treephys/tpae010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 01/05/2024] [Accepted: 01/14/2024] [Indexed: 01/22/2024]
Abstract
Limited information is available on the variation of plant leaf hydraulic traits in relation to soil rock fragment content (RFC), particularly for xerophytes native to rocky mountain areas. In this study, we conducted a field experiment with four gradients of RFC (0, 25, 50 and 75% ν ν-1) on three different xerophytic species (Sophora davidii, Cotinus szechuanensis and Bauhinia brachycarpa). We measured predawn and midday leaf water potential (Ψleaf), leaf hydraulic conductance (Kleaf), Ψleaf induced 50% loss of Kleaf (P50), pressure-volume curve traits and leaf structure. A consistent response of hydraulic traits to increased RFC was observed in three species. Kleaf showed a decrease, whereas P50 and turgor loss point (Ψtlp) became increasingly negative with increasing RFC. Thus, a clear trade-off between hydraulic efficiency and safety was observed in the xerophytic species. In all three species, the reduction in Kleaf was associated with an increase in leaf mass per area. In S. davidii, alterations in Kleaf and P50 were driven by leaf vein density (VLA) and Ψtlp. In C. szechuanensis, Ψtlp and VLA drove the changes in Kleaf and P50, respectively. In B. brachycarpa, changes in P50 were driven by VLA, whereas changes in both Kleaf and P50 were simultaneously influenced by Ψtlp. Our findings suggest that adaptation to increased rockiness necessarily implies a trade-off between leaf hydraulic efficiency and safety in xerophytic species. Additionally, the trade-off between leaf hydraulic efficiency and safety among xerophytic species is likely to result from processes occurring in the xylem and the outside-xylem hydraulic pathways. These findings contribute to a better understanding of the survival strategies and mechanisms of xerophytes in rocky soils, and provide a theoretical basis for the persistence of xerophytic species in areas with stony substrates.
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Affiliation(s)
- Xiulong Zhang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
| | - Shaowei Ma
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Hui Hu
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Fanglan Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
| | - Weikai Bao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
| | - Long Huang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Shijingshan District, Beijing 100049, China
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14
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Ávila-Lovera E, Haro R, Choudhary M, Acosta-Rangel A, Pratt RB, Santiago LS. The benefits of woody plant stem photosynthesis extend to hydraulic function and drought survival in Parkinsonia florida. Tree Physiol 2024; 44:tpae013. [PMID: 38284819 PMCID: PMC10918054 DOI: 10.1093/treephys/tpae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 01/16/2024] [Accepted: 01/21/2024] [Indexed: 01/30/2024]
Abstract
As climate change exacerbates drought stress in many parts of the world, understanding plant physiological mechanisms for drought survival is critical to predicting ecosystem responses. Stem net photosynthesis, which is common in arid environments, may be a drought survival trait, but whether the additional carbon fixed by stems contributes to plant hydraulic function and drought survival in arid land plants is untested. We conducted a stem light-exclusion experiment on saplings of a widespread North American desert tree species, Parkinsonia florida L., and after shading acclimation, we then subjected half of the plants to a drought treatment to test the interaction between light exclusion and water limitation on growth, leaf and stem photosynthetic gas exchange, xylem embolism assessed with micro-computed tomography and gravimetric techniques, and survival. Growth, stem photosynthetic gas exchange, hydraulic function and survival all showed expected reductions in response to light exclusion. However, stem photosynthesis mitigated the drought-induced reductions in gas exchange, xylem embolism (percent loss of conductivity, PLC) and mortality. The highest mortality was in the combined light exclusion and drought treatment, and was related to stem PLC and native sapwood-specific hydraulic conductivity. This research highlights the integration of carbon economy and water transport. Our results show that additional carbon income by photosynthetic stems has an important role in the growth and survival of a widespread desert tree species during drought. This shift in function under conditions of increasing stress underscores the importance of considering stem photosynthesis for predicting drought-induced mortality not only for the additional supply of carbon, but also for its extended benefits for hydraulic function.
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Affiliation(s)
- Eleinis Ávila-Lovera
- School of Biological Sciences, The University of Utah, 257 S 1400 E, Salt Lake City, UT 84112, USA
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama, Republic of Panama
| | - Roxana Haro
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Manika Choudhary
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Aleyda Acosta-Rangel
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - R Brandon Pratt
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - Louis S Santiago
- Department of Botany and Plant Sciences, University of California, 2150 Batchelor Hall, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama, Republic of Panama
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15
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Niccoli F, Kabala JP, Pacheco-Solana A, Battipaglia G. Impact of intra-annual wood density fluctuation on tree hydraulic function: insights from a continuous monitoring approach. Tree Physiol 2024; 44:tpad145. [PMID: 38070187 DOI: 10.1093/treephys/tpad145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 12/01/2023] [Indexed: 02/09/2024]
Abstract
Climate change significantly impacts global forests, leading to tree decline and dieback. To cope with climate change, trees develop several functional traits, such as intra-annual density fluctuations (IADFs) in tree rings. The formation of these traits facilitates trees to optimize resource allocation, allowing them to withstand periods of stress and eventually recover when the conditions become favourable again. This study focuses on a Pinus pinaster Aiton forest in a warm, drought-prone Mediterranean area, comparing two growing seasons with different weather patterns. The innovative continuous monitoring approach used in this study combines high-resolution monitoring of sap flow (SF), analysis of xylogenesis and quantitative wood anatomy. Our results revealed the high plasticity of P. pinaster in water use and wood formation, shedding light on the link between IADFs and tree conductance. Indeed, the capacity to form large cells in autumn (as IADFs) improves the total xylem hydraulic conductivity of this species. For the first time, a continuous SF measurement system captured the dynamics of bimodal SF during the 2022 growing season in conjunction with the bimodal growth pattern observed through xylogenesis monitoring. These results highlight the intricate interplay between environmental conditions, water use, wood formation and tree physiology, providing valuable insights into the acclimation mechanisms employed by P. pinaster to cope with weather fluctuations.
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Affiliation(s)
- Francesco Niccoli
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania 'L. Vanvitelli', Via Vivaldi 43, Caserta 81100, Italy
| | - Jerzy Piotr Kabala
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania 'L. Vanvitelli', Via Vivaldi 43, Caserta 81100, Italy
| | - Arturo Pacheco-Solana
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania 'L. Vanvitelli', Via Vivaldi 43, Caserta 81100, Italy
- Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964, USA
| | - Giovanna Battipaglia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania 'L. Vanvitelli', Via Vivaldi 43, Caserta 81100, Italy
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16
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Li Z, Luo D, Ibrahim MM, Hou E, Wang C. Adaptive strategies to freeze-thaw cycles in branch hydraulics of tree species coexisting in a temperate forest. Plant Physiol Biochem 2024; 206:108223. [PMID: 38043252 DOI: 10.1016/j.plaphy.2023.108223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/04/2023] [Accepted: 11/21/2023] [Indexed: 12/05/2023]
Abstract
Freeze-thaw cycles (FTCs) limit the distribution and survival of temperate tree species. Tree species with different wood types coexist in temperate forests and are subjected to the same FTCs. It is essential to understand how these trees differentially cope with xylem hydraulic failure induced by FTCs in the field. The branch hydraulic traits and nonstructural carbohydrate concentration of six coexisting tree species in a temperate forest were measured from mid-winter to early spring when the FTCs occurred from January to April. The percentage loss of hydraulic conductivity (PLC) was lower, and the water potential inducing a 50% loss of hydraulic conductivity (P50) was more negative in tracheid trees than in ring- and diffuse-porous trees, suggesting tracheid trees with narrow tracheid diameters showed less vulnerable to embolism and provided a lower degree of hydraulic failure during FTCs (stronger resistance). Ring-porous trees always showed lower hydraulic conductivity and higher PLC and P50, and these traits did not change during FTCs, suggesting that they might lose the hydraulic functions in winter and abandon the last year xylem. The P50 in diffuse-porous increased after several FTCs (frost fatigue), but that in tracheid species continued to increase (or even decrease) until the end of FTCs (69 cycles), suggesting that tracheid trees were less sensitive to frost fatigue than diffuse-porous trees. Soluble sugar concentration in deciduous trees negatively correlated with PLC at the end of FTCs, indicating that the effect of soluble sugar on refilling embolism occurred in early spring. While the soluble sugar concentration of deciduous trees decreased, that of two evergreen tracheid trees gradually increased, possibly due to the winter photosynthesis of evergreen leaves. Our results suggest temperate trees adopt different strategies to cope with the same FTCs. These findings enrich the understanding of plant hydraulics and carbon physiology in winter and provide insights into the response of different species coexisting in temperate forests under climate change.
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Affiliation(s)
- Zhimin Li
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China; Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
| | - Dandan Luo
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China
| | - Muhammed Mustapha Ibrahim
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Enqing Hou
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Chuankuan Wang
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China.
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17
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Wei Y, Chen YJ, Siddiq Z, Zhang JL, Zhang SB, Jansen S, Cao KF. Hydraulic traits and photosynthesis are coordinated with trunk sapwood capacitance in tropical tree species. Tree Physiol 2023; 43:2109-2120. [PMID: 37672225 DOI: 10.1093/treephys/tpad107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 08/28/2023] [Indexed: 09/07/2023]
Abstract
Water stored in trunk sapwood is vital for the canopy to maintain its physiological function under high transpiration demands. Little is known regarding the anatomical properties that contribute to the hydraulic capacitance of tree trunks and whether trunk capacitance is correlated with the hydraulic and gas exchange traits of canopy branches. We examined sapwood capacitance, xylem anatomical characteristics of tree trunks, embolism resistance, the minimal xylem water potential of canopy branches, leaf photosynthesis and stomatal conductance in 22 species from a tropical seasonal rainforest and savanna. The results showed that the mean trunk sapwood capacitance did not differ between the two biomes. Capacitance was closely related to the fiber lumen fraction and fiber wall reinforcement and not to the axial and ray parenchyma fractions. Additionally, it was positively correlated with the theoretical hydraulic conductivity of a trunk and the specific hydraulic conductivity of branches, and showed a trade-off with branch embolism resistance. Species with a high trunk sapwood capacitance maintained less negative canopy water potentials in the dry season, but higher leaf photosynthetic rates and stomatal conductance in the wet season. This study provides a functional link among trunk sapwood capacitance, xylem anatomy, canopy hydraulics and photosynthesis in tropical trees.
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Affiliation(s)
- Yang Wei
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
| | - Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang 653300, Yunnan, China
| | - Zafar Siddiq
- Department of Botany, Government College University, Katchery Road, Lahore 54000, Punjab, Pakistan
| | - Jiao-Lin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
| | - Steven Jansen
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Baden-Wurttemberg, Germany
| | - Kun-Fang Cao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
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18
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Waite PA, Leuschner C, Delzon S, Triadiati T, Saad A, Schuldt B. Plasticity of wood and leaf traits related to hydraulic efficiency and safety is linked to evaporative demand and not soil moisture in rubber (Hevea brasiliensis). Tree Physiol 2023; 43:2131-2149. [PMID: 37707940 DOI: 10.1093/treephys/tpad113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/15/2023]
Abstract
The predicted increase of drought intensity in South-East Asia has raised concern about the sustainability of rubber (Hevea brasiliensis Müll. Arg.) cultivation. In order to quantify the degree of phenotypic plasticity in this important tree crop species, we analysed a set of wood and leaf traits related to the hydraulic safety and efficiency in PB260 clones from eight small-holder plantations in Jambi province, Indonesia, representing a gradient in local microclimatic and edaphic conditions. Across plots, branch embolism resistance (P50) ranged from -2.14 to -2.58 MPa. The P50 and P88 values declined, and the hydraulic safety margin increased, with an increase in the mean annual vapour pressure deficit (VPD). Among leaf traits, only the changes in specific leaf area were related to the differences in evaporative demand. These variations of hydraulic trait values were not related to soil moisture levels. We did not find a trade-off between hydraulic safety and efficiency, but vessel density (VD) emerged as a major trait associated with both safety and efficiency. The VD, and not vessel diameter, was closely related to P50 and P88 as well as to specific hydraulic conductivity, the lumen-to-sapwood area ratio and the vessel grouping index. In conclusion, our results demonstrate some degree of phenotypic plasticity in wood traits related to hydraulic safety in this tropical tree species, but this is only in response to the local changes in evaporative demand and not soil moisture. Given that VPD may increasingly limit plant growth in a warmer world, our results provide evidence of hydraulic trait changes in response to a rising evaporative demand.
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Affiliation(s)
- Pierre-André Waite
- Institute of Forest Botany and Forest Zoology, Technical University of Dresden, Pienner Straße 7, Tharandt 01737, Germany
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, Goettingen 37073, Germany
| | - Christoph Leuschner
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, Goettingen 37073, Germany
| | - Sylvain Delzon
- Department of Biodiversity, Genes, and Communities (BIOGECO), Institut National de Recherche pour Agriculture, Alimentation et Environnement (INRAE), Université Bordeaux, Bat. 2 Allée Geoffroy St-Hilaire, Pessac 33615, France
| | - Triadiati Triadiati
- Department of Biology, Faculty of Mathematics and Natural Sciences, Bogor IPB University, Darmaga Campus, Bogor 16680, Indonesia
| | - Asmadi Saad
- Department of Soil Science, University of Jambi, Jalan Raya Jambi Muara Bulian KM 15 Mandalo Indah, Jambi, Sumatra 36361, Indonesia
| | - Bernhard Schuldt
- Institute of Forest Botany and Forest Zoology, Technical University of Dresden, Pienner Straße 7, Tharandt 01737, Germany
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, Goettingen 37073, Germany
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19
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Liu Q, Wang YX, Zeng Y, Mao JR, Xu XY, Liu Y. [Anatomical structure and physiological characteristics of Robinia pseudoacacia of different stand ages]. Ying Yong Sheng Tai Xue Bao 2023; 34:3256-3262. [PMID: 38511364 DOI: 10.13287/j.1001-9332.202312.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Drought intensity and frequency have been increased as a result of global warming. Exploring the drought resistance mechanism of Robinia pseudoacacia plantations of different stand ages on the Loess Plateau is crucial for understanding the stability of forest productivity in the region. We investigated anatomical traits, hydraulic function, and non-structural carbohydrate content of the xylem, as well as their association, in R. pseudoacacia plantations of different stand ages in a semi-arid region. The results showed that the vessel diameter, total pit membrane area, pit membrane area, vesture area, and vestured overlap of young and middle-aged stands were larger than those of mature stands, and the pit density was significantly lower in mature stands. Hydraulic conductivity was significantly related to vessel diameter, pit membrane area, and vesture area. Hydraulic conductivities of branches in young, middle-aged, and mature stands were 2.30, 2.12, and 0.76 kg·m-1·s-1·MPa-1, respectively, with embolism values of 54.5%, 53.8%, and 45.1%. Hydraulic conductivity was significantly related to soluble sugar and starch contents. The soluble sugar contents of branches in young, middle-aged and mature stands were 4.9%, 4.2%, and 3.8%, respectively. Xylem growth capacity of R. pseudoacacia in mature stand declined, resulting in the formation of small vessels with many small pits, which reduced hydraulic conductivity while maintaining hydraulic safety, resulting in a decrease of non-structural carbohydrates content. This study revealed the drought response mechanism of R. pseudoacacia plantations with different ages, providing a scientific foundation for the management and nurturing of R. pseudoacacia plantations on the Loess Plateau.
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Affiliation(s)
- Qing Liu
- College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yun-Xia Wang
- College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yan Zeng
- College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Ji-Rong Mao
- College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Xiao-Yang Xu
- College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Ying Liu
- College of Soil and Water Conservation Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China
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20
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Laughlin DC, Siefert A, Fleri JR, Tumber-Dávila SJ, Hammond WM, Sabatini FM, Damasceno G, Aubin I, Field R, Hatim MZ, Jansen S, Lenoir J, Lens F, McCarthy JK, Niinemets Ü, Phillips OL, Attorre F, Bergeron Y, Bruun HH, Byun C, Ćušterevska R, Dengler J, De Sanctis M, Dolezal J, Jiménez-Alfaro B, Hérault B, Homeier J, Kattge J, Meir P, Mencuccini M, Noroozi J, Nowak A, Peñuelas J, Schmidt M, Škvorc Ž, Sultana F, Ugarte RM, Bruelheide H. Rooting depth and xylem vulnerability are independent woody plant traits jointly selected by aridity, seasonality, and water table depth. New Phytol 2023; 240:1774-1787. [PMID: 37743552 DOI: 10.1111/nph.19276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 08/29/2023] [Indexed: 09/26/2023]
Abstract
Evolutionary radiations of woody taxa within arid environments were made possible by multiple trait innovations including deep roots and embolism-resistant xylem, but little is known about how these traits have coevolved across the phylogeny of woody plants or how they jointly influence the distribution of species. We synthesized global trait and vegetation plot datasets to examine how rooting depth and xylem vulnerability across 188 woody plant species interact with aridity, precipitation seasonality, and water table depth to influence species occurrence probabilities across all biomes. Xylem resistance to embolism and rooting depth are independent woody plant traits that do not exhibit an interspecific trade-off. Resistant xylem and deep roots increase occurrence probabilities in arid, seasonal climates over deep water tables. Resistant xylem and shallow roots increase occurrence probabilities in arid, nonseasonal climates over deep water tables. Vulnerable xylem and deep roots increase occurrence probabilities in arid, nonseasonal climates over shallow water tables. Lastly, vulnerable xylem and shallow roots increase occurrence probabilities in humid climates. Each combination of trait values optimizes occurrence probabilities in unique environmental conditions. Responses of deeply rooted vegetation may be buffered if evaporative demand changes faster than water table depth under climate change.
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Affiliation(s)
- Daniel C Laughlin
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - Andrew Siefert
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | - Jesse R Fleri
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
| | | | - William M Hammond
- Agronomy Department, University of Florida, Gainesville, FL, 32611, USA
| | - Francesco Maria Sabatini
- BIOME Lab, Department of Biological, Geological and Environmental Sciences (BiGeA), Alma Mater Studiorum University of Bologna, Via Irnerio 42, 40126, Bologna, Italy
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 21, Praha 6, Suchdol, Czech Republic
| | - Gabriella Damasceno
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig, 04103, Germany
- Institute of Biology and Geobotany and Botanical Garden, Martin-Luther University, Halle-Wittenberg, Halle, 06108, Germany
| | - Isabelle Aubin
- Great Lakes Forestry Centre, Canadian Forest Service, Natural Resources Canada, Sault Ste. Marie, Ontario, P6A 2E5, Canada
| | - Richard Field
- School of Geography, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Mohamed Z Hatim
- Plant Ecology and Nature Conservation Group, Environmental Sciences Department, Wageningen University and Research, 6700 AA, Wageningen, the Netherlands
- Botany and Microbiology Department, Tanta University, Tanta, 3527, Egypt
| | - Steven Jansen
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm, 89081, Germany
| | - Jonathan Lenoir
- UMR CNRS 7058, Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN), Université de Picardie Jules Verne, 80000, Amiens, France
| | - Frederic Lens
- Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, the Netherlands
- Plant Sciences, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, the Netherlands
| | | | - Ülo Niinemets
- Crop Science and Plant Biology, Estonian University of Life Sciences, Tartu, 51006, Estonia
| | | | - Fabio Attorre
- Department of Environmental Biology, Sapienza University of Rome, Rome, 00185, Italy
| | - Yves Bergeron
- Institut de recherche sur les forêts Université du Québec en Abitibi-Témiscamingue, 445 boul. de l'université, Rouyn-Noranda, Québec, J9X5E4, Canada
| | - Hans Henrik Bruun
- Department of Biology, University of Copenhagen, 2100, Copenhagen Ø, Denmark
| | - Chaeho Byun
- Department of Biological Science, Andong National University, Andong-si, 36729, South Korea
| | - Renata Ćušterevska
- Institute of Biology, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University, 1000, Skopje, North Macedonia
| | - Jürgen Dengler
- Vegetation Ecology Research Group, Institute of Natural Resource Sciences (IUNR), Zurich University of Applied Sciences (ZHAW), 8820, Wädenswil, Switzerland
- Plant Ecology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95447, Bayreuth, Germany
| | - Michele De Sanctis
- Department of Environmental Biology, Sapienza University of Rome, Rome, 00185, Italy
| | - Jiri Dolezal
- Department of Functional Ecology, Institute of Botany, Czech Academy of Sciences, Trebon, Czech Republic
- Department of Botany, Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Borja Jiménez-Alfaro
- Biodiversity Research Institute (Univ. Oviedo-CSIC-Princ. Asturias), Mieres, Asturias, Spain
| | - Bruno Hérault
- CIRAD, UPR Forêts et Sociétés, F-34398, Montpellier, France
- Forêts et Sociétés, Univ Montpellier, CIRAD, Montpellier, France
| | - Jürgen Homeier
- Plant Ecology and Ecosystems Research, University of Goettingen, 37073, Goettingen, Germany
- Resource Management, HAWK University of Applied Sciences and Arts, 37077, Goettingen, Germany
| | - Jens Kattge
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig, 04103, Germany
- Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Patrick Meir
- School of Geosciences, University of Edinburgh, Edinburgh, UK
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Maurizio Mencuccini
- CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain
- ICREA, 08010, Barcelona, Spain
| | - Jalil Noroozi
- Department of Botany and Biodiversity Research, Universitiy of Vienna, 1030, Vienna, Austria
| | - Arkadiusz Nowak
- Botanical Garden, Polish Academy of Sciences, Warsaw, Poland
- Department of Botany and Nature Protection, University of Warmia and Mazury, Olsztyn, Poland
| | - Josep Peñuelas
- CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain
- Global Ecology Unit CREAF-CSIC-UAB, CSIC, Bellaterra, 08193, Barcelona, Catalonia, Spain
| | - Marco Schmidt
- Palmengarten der Stadt Frankfurt am Main, 60323, Frankfurt am Main, Germany
| | - Željko Škvorc
- Faculty of Forestry and Wood Technology, University of Zagreb, 10000, Zagreb, Croatia
| | - Fahmida Sultana
- Department of Forestry and Environmental Science, Shahjalal University of Science and Technology, Sylhet, Bangladesh
| | - Rosina Magaña Ugarte
- Botany Unit, Department of Pharmacology, Pharmacognosy and Botany, Faculty of Pharmacy, Universidad Complutense de Madrid, Madrid, Spain
| | - Helge Bruelheide
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig, 04103, Germany
- Institute of Biology and Geobotany and Botanical Garden, Martin-Luther University, Halle-Wittenberg, Halle, 06108, Germany
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21
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Petek-Petrik A, Petrík P, Lamarque LJ, Cochard H, Burlett R, Delzon S. Drought survival in conifer species is related to the time required to cross the stomatal safety margin. J Exp Bot 2023; 74:6847-6859. [PMID: 37681745 DOI: 10.1093/jxb/erad352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 09/07/2023] [Indexed: 09/09/2023]
Abstract
The regulation of water loss and the spread of xylem embolism have mostly been considered separately. The development of an integrated approach taking into account the temporal dynamics and relative contributions of these mechanisms to plant drought responses is urgently needed. Do conifer species native to mesic and xeric environments display different hydraulic strategies and temporal sequences under drought? A dry-down experiment was performed on seedlings of four conifer species differing in embolism resistance, from drought-sensitive to extremely drought-resistant species. A set of traits related to drought survival was measured, including turgor loss point, stomatal closure, minimum leaf conductance, and xylem embolism resistance. All species reached full stomatal closure before the onset of embolism, with all but the most drought-sensitive species presenting large stomatal safety margins, demonstrating that highly drought-resistant species do not keep their stomata open under drought conditions. Plant dry-down time to death was significantly influenced by the xylem embolism threshold, stomatal safety margin, and minimum leaf conductance, and was best explained by the newly introduced stomatal margin retention index (SMRIΨ50) which reflects the time required to cross the stomatal safety margin. The SMRIΨ50 may become a key tool for the characterization of interspecific drought survival variability in trees.
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Affiliation(s)
- Anja Petek-Petrik
- Department of Vegetation Ecology, Institute of Botany, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Peter Petrík
- Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), 82467 Garmisch-Partenkirchen, Germany
| | - Laurent J Lamarque
- BIOGECO, University of Bordeaux, INRAE, F-33615 Pessac, France
- Département des Sciences de l'Environnement, UQTR, Trois-Rivières, Québec, Canada
| | - Hervé Cochard
- PIAF, University of Clermont Auvergne, INRAE, 63000 Clermont-Ferrand, France
| | - Régis Burlett
- BIOGECO, University of Bordeaux, INRAE, F-33615 Pessac, France
| | - Sylvain Delzon
- BIOGECO, University of Bordeaux, INRAE, F-33615 Pessac, France
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22
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Sorek Y, Netzer Y, Cohen S, Hochberg U. Rapid leaf xylem acclimation diminishes the chances of embolism in grapevines. J Exp Bot 2023; 74:6836-6846. [PMID: 37659088 DOI: 10.1093/jxb/erad351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 09/01/2023] [Indexed: 09/04/2023]
Abstract
Under most conditions tight stomatal regulation in grapevines (Vitis vinifera) avoids xylem embolism. The current study evaluated grapevine responses to challenging scenarios that might lead to leaf embolism and consequential leaf damage. We hypothesized that embolism would occur if the vines experienced low xylem water potential (Ψx) shortly after bud break or later in the season under a combination of extreme drought and heat. We subjected vines to two potentially dangerous environments: (i) withholding irrigation from a vineyard grown in a heatwave-prone environment, and (ii) subjecting potted vines to terminal drought 1 month after bud break. In the field experiment, a heatwave at the beginning of August resulted in leaf temperatures over 45 °C. However, effective stomatal response maintained the xylem water potential (Ψx) well above the embolism threshold, and no leaf desiccation was observed. In the pot experiment, leaves of well-watered vines in May were relatively vulnerable to embolism with 50% embolism (P50) at -1.8 MPa. However, when exposed to drought, these leaves acclimated their leaf P50 by 0.65 MPa in less than a week and before reaching embolism values. When dried to embolizing Ψx, the leaf damage proportion matched (percentage-wise) the leaf embolism level. Our findings indicate that embolism and leaf damage are usually avoided by the grapevines' efficient stomatal regulation and rapid acclimation of their xylem vulnerability.
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Affiliation(s)
- Yonatan Sorek
- Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Yishai Netzer
- Department of Chemical Engineering, Ariel University, Ariel 40700, Israel
- Eastern R and D Center, Ariel 40700, Israel
| | - Shabtai Cohen
- Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel
| | - Uri Hochberg
- Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel
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23
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Zhang G, Mao Z, Maillard P, Brancheriau L, Gérard B, Engel J, Fortunel C, Heuret P, Maeght JL, Martínez-Vilalta J, Stokes A. Functional trade-offs are driven by coordinated changes among cell types in the wood of angiosperm trees from different climates. New Phytol 2023; 240:1162-1176. [PMID: 37485789 DOI: 10.1111/nph.19132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/20/2023] [Indexed: 07/25/2023]
Abstract
Wood performs several functions to ensure tree survival and carbon allocation to a finite stem volume leads to trade-offs among cell types. It is not known to what extent these trade-offs modify functional trade-offs and if they are consistent across climates and evolutionary lineages. Twelve wood traits were measured in stems and coarse roots across 60 adult angiosperm tree species from temperate, Mediterranean and tropical climates. Regardless of climate, clear trade-offs occurred among cellular fractions, but did not translate into specific functional trade-offs. Wood density was negatively related to hydraulic conductivity (Kth ) in stems and roots, but was not linked to nonstructural carbohydrates (NSC), implying a functional trade-off between mechanical integrity and transport but not with storage. NSC storage capacity was positively associated with Kth in stems and negatively in roots, reflecting a potential role for NSC in the maintenance of hydraulic integrity in stems but not in roots. Results of phylogenetic analyses suggest that evolutionary histories cannot explain covariations among traits. Trade-offs occur among cellular fractions, without necessarily modifying trade-offs in function. However, functional trade-offs are driven by coordinated changes among xylem cell types depending on the dominant role of each cell type in stems and roots.
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Affiliation(s)
- Guangqi Zhang
- AMAP, University of Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
- SILVA, INRAE, Université de Lorraine, Agroparistech, Centre de Recherche Grand-Est Nancy, Champenoux, 54280, France
| | - Zhun Mao
- AMAP, University of Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Pascale Maillard
- SILVA, INRAE, Université de Lorraine, Agroparistech, Centre de Recherche Grand-Est Nancy, Champenoux, 54280, France
| | - Loïc Brancheriau
- CIRAD, UPR BioWooEB, Montpellier, 34000, France
- BioWooEB, University of Montpellier, CIRAD, Montpellier, 34000, France
| | - Bastien Gérard
- SILVA, INRAE, Université de Lorraine, Agroparistech, Centre de Recherche Grand-Est Nancy, Champenoux, 54280, France
| | - Julien Engel
- AMAP, University of Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Claire Fortunel
- AMAP, University of Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Patrick Heuret
- AMAP, University of Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Jean-Luc Maeght
- AMAP, University of Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Jordi Martínez-Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, E08193, Spain
- Universitat Autònoma Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, E08193, Spain
| | - Alexia Stokes
- AMAP, University of Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
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24
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Watanabe Y, Yamagishi S, Takata N, Tsuyama T, Yasue K, Ohno Y. Formation of xylem tissues and secondary cell walls is diminished by severe and consecutive insect defoliation. Am J Bot 2023; 110:e16232. [PMID: 37661818 DOI: 10.1002/ajb2.16232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 09/05/2023]
Abstract
PREMISE Insect defoliation of trees causes unusual changes to wood anatomy and slows radial growth that decreases tree value; however, the characteristics of these anatomical changes in hardwoods remain unclear. The aim of this study was to characterize the anatomy and histochemistry of the wood in trunks of Betula maximowicziana trees after severe insect defoliation. METHODS Secondary xylem tissues were sampled from trunks that had been defoliated by Caligula japonica at Naie and Furano in central Hokkaido during 2006-2012, then cross-dated and examined microscopically and stained histochemically to characterize anatomical and chemical changes in the cells. RESULTS White rings with thin-walled wood fibers and greatly reduced annual ring width in the subsequent year were observed in samples from both sites. From these results, the year that the white rings formed was determined, and severe defoliation was confirmed to trigger white ring formation. The characteristics may prove useful to detect the formation year of white rings. Scanning electron microscopy and histochemical analyses of the white rings indicated that the thickness of the S2 layer in the wall of wood fiber cells decreased, but xylan and lignin were still deposited in the cell walls of wood fibers. However, the walls of the fibers rethickened after the defoliation. CONCLUSIONS Our results suggest that B. maximowicziana responds to a temporary lack of carbon inputs due to insect defoliation by regulating the thickness of the S2 layer of the cell wall of wood fibers. For B. maximowicziana, insect defoliation late in the growing season has serious deleterious effects on wood formation and radial growth.
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Affiliation(s)
- Yoko Watanabe
- Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Shohei Yamagishi
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
- Forestry and Forest Products Research Institute, Tsukuba, 305-8687, Japan
| | - Naoki Takata
- Forest Bio-Research Center, Forestry and Forest Products Research Institute, Hitachi, 319-1301, Japan
| | - Taku Tsuyama
- Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192, Japan
| | - Koh Yasue
- Institute for Mountain Science, Shinshu University, Minami-minowa, 399-4598, Japan
| | - Yasuyuki Ohno
- Forest Research Institute, Hokkaido Research Organization, Bibai, 079-0198, Japan
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25
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Liu Y, Nadezhdina N, Hu W, Clothier B, Duan J, Li X, Xi B. Evaporation-driven internal hydraulic redistribution alleviates root drought stress: Mechanisms and modeling. Plant Physiol 2023; 193:1058-1072. [PMID: 37350505 DOI: 10.1093/plphys/kiad364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 06/02/2023] [Accepted: 06/05/2023] [Indexed: 06/24/2023]
Abstract
Many tree species have developed extensive root systems that allow them to survive in arid environments by obtaining water from a large soil volume. These root systems can transport and redistribute soil water during drought by hydraulic redistribution (HR). A recent study revealed the phenomenon of evaporation-driven hydraulic redistribution (EDHR), which is driven by evaporative demand (transpiration). In this study, we confirmed the occurrence of EDHR in Chinese white poplar (Populus tomentosa) through root sap flow measurements. We utilized microcomputed tomography technology to reconstruct the xylem network of woody lateral roots and proposed conceptual models to verify EDHR from a physical perspective. Our results indicated that EDHR is driven by the internal water potential gradient within the plant xylem network, which requires 3 conditions: high evaporative demand, soil water potential gradient, and special xylem structure of the root junction. The simulations demonstrated that during periods of extreme drought, EDHR could replenish water to dry roots and improve root water potential up to 38.9% to 41.6%. This highlights the crucial eco-physiological importance of EDHR in drought tolerance. Our proposed models provide insights into the complex structure of root junctions and their impact on water movement, thus enhancing our understanding of the relationship between xylem structure and plant hydraulics.
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Affiliation(s)
- Yang Liu
- Laboratory for Silviculture and Forest Ecosystem in Arid- and Semi-Arid Region of State Forestry and Grassland Administration, Beijing Forestry University, Beijing 10083, China
- Ministry of Education Key Laboratory of Silviculture and Conservation, Beijing Forestry University, Beijing 100083, China
| | - Nadezhda Nadezhdina
- Institute of Forest Botany, Dendrology and Geobiocenology, Mendel University in Brno, Zemedelska 3, Brno 61300, Czech Republic
| | - Wei Hu
- New Zealand Institute for Plant & Food Research Ltd., Private Bag 4707, Christchurch 8140, New Zealand
| | - Brent Clothier
- New Zealand Institute for Plant & Food Research Ltd., Fitzherbert Science Centre, Palmerston North 4442, New Zealand
| | - Jie Duan
- Laboratory for Silviculture and Forest Ecosystem in Arid- and Semi-Arid Region of State Forestry and Grassland Administration, Beijing Forestry University, Beijing 10083, China
- Ministry of Education Key Laboratory of Silviculture and Conservation, Beijing Forestry University, Beijing 100083, China
| | - Ximeng Li
- College of Life and Environmental Science, Minzu University of China, Beijing 100081, China
| | - Benye Xi
- Laboratory for Silviculture and Forest Ecosystem in Arid- and Semi-Arid Region of State Forestry and Grassland Administration, Beijing Forestry University, Beijing 10083, China
- Ministry of Education Key Laboratory of Silviculture and Conservation, Beijing Forestry University, Beijing 100083, China
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26
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Scoffoni C, Albuquerque C, Buckley TN, Sack L. The dynamic multi-functionality of leaf water transport outside the xylem. New Phytol 2023; 239:2099-2107. [PMID: 37386735 DOI: 10.1111/nph.19069] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 05/12/2023] [Indexed: 07/01/2023]
Abstract
A surge of papers have reported low leaf vulnerability to xylem embolism during drought. Here, we focus on the less studied, and more sensitive, outside-xylem leaf hydraulic responses to multiple internal and external conditions. Studies of 34 species have resolved substantial vulnerability to dehydration of the outside-xylem pathways, and studies of leaf hydraulic responses to light also implicate dynamic outside-xylem responses. Detailed experiments suggest these dynamic responses arise at least in part from strong control of radial water movement across the vein bundle sheath. While leaf xylem vulnerability may influence leaf and plant survival during extreme drought, outside-xylem dynamic responses are important for the control and resilience of water transport and leaf water status for gas exchange and growth.
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Affiliation(s)
- Christine Scoffoni
- Department of Biological Sciences, California State University Los Angeles, 5151 State University Dr., Los Angeles, CA, 90032, USA
| | - Caetano Albuquerque
- Department of Biological Sciences, California State University Los Angeles, 5151 State University Dr., Los Angeles, CA, 90032, USA
| | - Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, 1 Shields Ave, Davis, CA, 95616, USA
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 612 Charles E. Young Dr., Los Angeles, CA, 90095, USA
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27
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Nadal M, Carriquí M, Badel E, Cochard H, Delzon S, King A, Lamarque LJ, Flexas J, Torres-Ruiz JM. Photosynthesis, leaf hydraulic conductance and embolism dynamics in the resurrection plant Barbacenia purpurea. Physiol Plant 2023; 175:e14035. [PMID: 37882305 DOI: 10.1111/ppl.14035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 08/17/2023] [Accepted: 09/15/2023] [Indexed: 10/27/2023]
Abstract
The main parameters determining photosynthesis are stomatal and mesophyll conductance and electron transport rate, and for hydraulic dynamics they are leaf hydraulic conductance and the spread of embolism. These parameters have scarcely been studied in desiccation-tolerant (resurrection) plants exposed to drought. Here, we characterized photosynthesis and hydraulics during desiccation and rehydration in a poikilochlorophyllous resurrection plant, Barbacenia purpurea (Velloziaceae). Gas exchange, chlorophyll fluorescence, and leaf water status were monitored along the whole dehydration-rehydration cycle. Simultaneously, embolism formation and hydraulic functioning recovery were measured at leaf level using micro-computed tomography imaging. Photosynthesis and leaf hydraulic conductance ceased at relatively high water potential (-1.28 and -1.54 MPa, respectively), whereas the onset of leaf embolism occurred after stomatal closure and photosynthesis cessation (<-1.61 MPa). This sequence of physiological processes during water stress may be associated with the need to delay dehydration, to prepare the molecular changes required in the desiccated state. Complete rehydration occurred rapidly in the mesophyll, whereas partial xylem refilling, and subsequent recovery of photosynthesis, occurred at later stages after rewatering. These results highlight the importance of stomata as safety valves to protect the vascular system from embolism, even in a plant able to fully recover after complete embolism.
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Affiliation(s)
- Miquel Nadal
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Zaragoza, Spain
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB), Institut d'Investigacions Agroambientals i d'Economia de l'Aigua (INAGEA), Palma, Illes Balears, Spain
| | - Marc Carriquí
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB), Institut d'Investigacions Agroambientals i d'Economia de l'Aigua (INAGEA), Palma, Illes Balears, Spain
- Instituto de Ciencias Forestales (ICIFOR-INIA), CSIC, Madrid, Spain
| | - Eric Badel
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand, France
| | - Hervé Cochard
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand, France
| | | | - Andrew King
- Synchrotron Source Optimisée de Lumière d'Energie Intermédiaire du LURE, L'Orme de Merisiers, France
| | | | - Jaume Flexas
- Research Group on Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears (UIB), Institut d'Investigacions Agroambientals i d'Economia de l'Aigua (INAGEA), Palma, Illes Balears, Spain
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28
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Fernández-de-Uña L, Martínez-Vilalta J, Poyatos R, Mencuccini M, McDowell NG. The role of height-driven constraints and compensations on tree vulnerability to drought. New Phytol 2023; 239:2083-2098. [PMID: 37485545 DOI: 10.1111/nph.19130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/07/2023] [Indexed: 07/25/2023]
Abstract
Frequent observations of higher mortality in larger trees than in smaller ones during droughts have sparked an increasing interest in size-dependent drought-induced mortality. However, the underlying physiological mechanisms are not well understood, with height-associated hydraulic constraints often being implied as the potential mechanism driving increased drought vulnerability. We performed a quantitative synthesis on how key traits that drive plant water and carbon economy change with tree height within species and assessed the implications that the different constraints and compensations may have on the interacting mechanisms (hydraulic failure, carbon starvation and/or biotic-agent attacks) affecting tree vulnerability to drought. While xylem tension increases with tree height, taller trees present a range of structural and functional adjustments, including more efficient water use and transport and greater water uptake and storage capacity, that mitigate the path-length-associated drop in water potential. These adaptations allow taller trees to withstand episodic water stress. Conclusive evidence for height-dependent increased vulnerability to hydraulic failure and carbon starvation, and their coupling to defence mechanisms and pest and pathogen dynamics, is still lacking. Further research is needed, particularly at the intraspecific level, to ascertain the specific conditions and thresholds above which height hinders tree survival under drought.
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Affiliation(s)
- Laura Fernández-de-Uña
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Jordi Martínez-Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
| | - Rafael Poyatos
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
| | - Maurizio Mencuccini
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- ICREA, Barcelona, 08010, Spain
| | - Nate G McDowell
- Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
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Vuerich M, Petrussa E, Boscutti F, Braidot E, Filippi A, Petruzzellis F, Tomasella M, Tromba G, Pizzuto M, Nardini A, Secchi F, Casolo V. Contrasting Responses of Two Grapevine Cultivars to Drought: The Role of Non-structural Carbohydrates in Xylem Hydraulic Recovery. Plant Cell Physiol 2023; 64:920-932. [PMID: 37384580 DOI: 10.1093/pcp/pcad066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/18/2023] [Accepted: 06/26/2023] [Indexed: 07/01/2023]
Abstract
Xylem embolism is one of the possible outcomes of decreasing xylem pressure when plants face drought. Recent studies have proposed a role for non-structural carbohydrates (NSCs) in osmotic pressure generation, required for refilling embolized conduits. Potted cuttings of grapevine Grenache and Barbera, selected for their adaptation to different climatic conditions, were subjected to a drought stress followed by re-irrigation. Stem embolism rate and its recovery were monitored in vivo by X-ray micro-computed tomography (micro-CT). The same plants were further analyzed for xylem conduit dimension and NSC content. Both cultivars significantly decreased Ψpd in response to drought and recovered from xylem embolism after re-irrigation. However, although the mean vessel diameter was similar between the cultivars, Barbera was more prone to embolism. Surprisingly, vessel diameter was apparently reduced during recovery in this cultivar. Hydraulic recovery was linked to sugar content in both cultivars, showing a positive relationship between soluble NSCs and the degree of xylem embolism. However, when starch and sucrose concentrations were considered separately, the relationships showed cultivar-specific and contrasting trends. We showed that the two cultivars adopted different NSC-use strategies in response to drought, suggesting two possible scenarios driving conduit refilling. In Grenache, sucrose accumulation seems to be directly linked to embolism formation and possibly sustains refilling. In Barbera, maltose/maltodextrins could be involved in a conduit recovery strategy via the formation of cell-wall hydrogels, likely responsible for the reduction of conduit lumen detected by micro-CT.
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Affiliation(s)
- Marco Vuerich
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Via delle Scienze 91, Udine 33100, Italy
| | - Elisa Petrussa
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Via delle Scienze 91, Udine 33100, Italy
| | - Francesco Boscutti
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Via delle Scienze 91, Udine 33100, Italy
| | - Enrico Braidot
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Via delle Scienze 91, Udine 33100, Italy
| | - Antonio Filippi
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Via delle Scienze 91, Udine 33100, Italy
- Dipartimento di Area Medica, Università di Udine, Piazzale Kolbe 4, Udine 33100, Italy
| | - Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Martina Tomasella
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Giuliana Tromba
- Elettra-Sincrotrone Trieste, Area Science Park, Basovizza, Trieste 34149, Italy
| | - Mauro Pizzuto
- Vivai Cooperativi Rauscedo, Via Udine, 39, Rauscedo (PN) 33095, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Francesca Secchi
- Dipartimento di Scienze Agrarie, Forestali, Alimentari (DISAFA), Università di Torino, Largo Paolo Braccini 2, Grugliasco (TO) 10095, Italy
| | - Valentino Casolo
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Via delle Scienze 91, Udine 33100, Italy
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Secchi F, Bevilacqua I, Agliassa C, Maghrebi M, Cavalletto S, Morabito C, Lembo S, Vigani G. Alkaline soil primes the recovery from drought in Populus nigra plants through physiological and chemical adjustments. Plant Physiol Biochem 2023; 201:107838. [PMID: 37364510 DOI: 10.1016/j.plaphy.2023.107838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/04/2023] [Accepted: 06/13/2023] [Indexed: 06/28/2023]
Abstract
Perennial plants are frequently exposed to severe and prolonged drought, and when the balance between water transport and transpirational demand is compromised trees are in danger of embolism formation. To maintain the physiological balance, plants can rely on mechanisms to quickly recover the lost xylem hydraulic capacity and reduce the prolonged impact on photosynthetic activity upon rehydration. Among factors helpful for plants to sustain acclimation and adaptation responses to drought and promote recovery, maintaining an optimal nutritional status is crucial for plant survival. This study aimed to investigate the physiological and biochemical responses under drought and recovery of Populus nigra plants grown in soil with impaired nutrient bioavailability obtained by adding calcium oxide (CaO) to the substrate. Although the CaO treatment did not affect plant growth, in well-watered conditions, treated poplars displayed an impaired inorganic ions profile in tissues. Under drought, although CaO-treated and untreated plants showed similar physiological responses, the former closed the stomata earlier. During water stress relief, the CaO-treated poplars exhibited a faster stomatal opening and a higher capacity to restore xylem hydraulic conductivity compared to not-treated plants, probably due to the higher osmolyte accumulation during drought. The content of some inorganic ions (e.g, Ca2+ and Cl-) was also higher in the xylem sap collected from stressed CaO-treated plants, thus contributing to increase the osmotic gradient necessary for the recovery. Taken together, our results suggest that CaO treatment promotes a faster and more efficient plant recovery after drought due to a modulation of ions homeostasis.
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Affiliation(s)
- Francesca Secchi
- Department of Agriculture, Forest and Food Sciences, University of Turin, Grugliasco, Italy.
| | - Ivan Bevilacqua
- Department of Agriculture, Forest and Food Sciences, University of Turin, Grugliasco, Italy
| | - Chiara Agliassa
- Department of Agriculture, Forest and Food Sciences, University of Turin, Grugliasco, Italy
| | - Moez Maghrebi
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Silvia Cavalletto
- Department of Agriculture, Forest and Food Sciences, University of Turin, Grugliasco, Italy
| | - Cristina Morabito
- Department of Agriculture, Forest and Food Sciences, University of Turin, Grugliasco, Italy
| | - Silvia Lembo
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Gianpiero Vigani
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy.
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31
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Fickle JC, Pratt RB, Jacobsen AL. Xylem structure and hydraulic function in roots and stems of chaparral shrub species from high and low elevation in the Sierra Nevada, California. Physiol Plant 2023; 175:e13970. [PMID: 37401910 DOI: 10.1111/ppl.13970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/16/2023] [Accepted: 06/25/2023] [Indexed: 07/05/2023]
Abstract
Xylem structure and hydraulics were compared between individuals at lower and upper elevation distribution limits for five chaparral shrub species along a steep transect in the southern Sierra Nevada, California, USA. Higher-elevation plants experienced frequent winter freeze-thaw events and increased precipitation. We hypothesized that environmental differences would lead to xylem trait differences between high and low elevations, but predictions were complicated because both water stress (low elevation) and freeze-thaw events (high elevation) may select for similar traits, such as narrow vessel diameter. We found significant changes in the ratio of stem xylem area to leaf area (Huber value) between elevations, with more xylem area required to support leaves at low elevations. Co-occurring species significantly differed in their xylem traits, suggesting diverse strategies to cope with the highly seasonal environment of this Mediterranean-type climate region. Roots were more hydraulically efficient and more vulnerable to embolism relative to stems, potentially due to roots being buffered from freeze-thaw stress, which allows them to maintain wider diameter vessels. Knowledge of the structure and function of both roots and stems is likely important in understanding whole-plant response to environmental gradients.
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Affiliation(s)
- Jaycie C Fickle
- Department of Biology, California State University, Bakersfield, California, USA
- University of Utah, Salt Lake City, Utah, USA
| | - R Brandon Pratt
- Department of Biology, California State University, Bakersfield, California, USA
| | - Anna L Jacobsen
- Department of Biology, California State University, Bakersfield, California, USA
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32
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Férriz M, Martin-Benito D, Fernández-de-Simón MB, Conde M, García-Cervigón AI, Aranda I, Gea-Izquierdo G. Functional phenotypic plasticity mediated by water stress and [CO2] explains differences in drought tolerance of two phylogenetically close conifers. Tree Physiol 2023; 43:909-924. [PMID: 36809504 PMCID: PMC10255776 DOI: 10.1093/treephys/tpad021] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 02/15/2023] [Indexed: 06/11/2023]
Abstract
Forests are threatened globally by increased recurrence and intensity of hot droughts. Functionally close coexisting species may exhibit differences in drought vulnerability large enough to cause niche differentiation and affect forest dynamics. The effect of rising atmospheric [CO2], which could partly alleviate the negative effects of drought, may also differ between species. We analysed functional plasticity in seedlings of two taxonomically close pine species (Pinus pinaster Ait., Pinus pinea L.) under different [CO2] and water stress levels. The multidimensional functional trait variability was more influenced by water stress (preferentially xylem traits) and [CO2] (mostly leaf traits) than by differences between species. However, we observed differences between species in the strategies followed to coordinate their hydraulic and structural traits under stress. Leaf 13C discrimination decreased with water stress and increased under elevated [CO2]. Under water stress both species increased their sapwood area to leaf area ratios, tracheid density and xylem cavitation, whereas they reduced tracheid lumen area and xylem conductivity. Pinus pinea was more anisohydric than P. pinaster. Pinus pinaster produced larger conduits under well-watered conditions than P. pinea. Pinus pinea was more tolerant to water stress and more resistant to xylem cavitation under low water potentials. The higher xylem plasticity in P. pinea, particularly in tracheid lumen area, expressed a higher capacity of acclimation to water stress than P. pinaster. In contrast, P. pinaster coped with water stress comparatively more by increasing plasticity of leaf hydraulic traits. Despite the small differences observed in the functional response to water stress and drought tolerance between species, these interspecific differences agreed with ongoing substitution of P. pinaster by P. pinea in forests where both species co-occur. Increased [CO2] had little effect on the species-specific relative performance. Thus, a competitive advantage under moderate water stress of P. pinea compared with P. pinaster is expected to continue in the future.
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Affiliation(s)
- M Férriz
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - D Martin-Benito
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | | | - M Conde
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - A I García-Cervigón
- Department of Biology and Geology, Physics and Inorganic Chemistry Rey Juan Carlos University, c/Tulipán s/n, 28933 Móstoles, Spain
| | - I Aranda
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - G Gea-Izquierdo
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
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Xie Z, Gui J, Zhong Y, Li B, Sun J, Shen J, Li L. Screening genome-editing knockouts reveals the receptor-like kinase ASX role in regulations of secondary xylem development in Populus. New Phytol 2023; 238:1972-1985. [PMID: 36922397 DOI: 10.1111/nph.18881] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/07/2023] [Indexed: 05/04/2023]
Abstract
In trees, secondary xylem development is essential for the growth of perennial stem increments. Many signals regulate the process of development, but our knowledge of the molecular components involved in signal transduction is still limited. In this study, we identified Attenuation of Secondary Xylem (ASX) knockouts by screening genome-editing knockouts of xylem-expressed receptor-like kinases (RLKs) in Populus. The ASX role in secondary xylem development in Populus was discovered using biochemical, cellular, and genomic analyses. The ASX knockout plants had abnormal secondary stem growth but had little effect on shoot apical primary growth. ASX and SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK)2/4 were co-precipitated in developing xylem. Through their interaction, ASX is phosphorylated by SERK. Transcriptome analysis of developing xylem revealed that ASX deficiency inhibited the transcriptional activity of genes involved in xylem differentiation and secondary cell wall formation. By forming a complex, ASX and SERK may function as a signaling module for signal transduction required in the regulation of secondary xylem development in trees. This study shows that ASX, which encodes a RLKs, is required for secondary xylem development and sheds light on regulatory signals found in tree stem secondary growth.
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Affiliation(s)
- Zhi Xie
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinshan Gui
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China
| | - Yu Zhong
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Bo Li
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiayan Sun
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Junhui Shen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Laigeng Li
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
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Potkay A, Feng X. Do stomata optimize turgor-driven growth? A new framework for integrating stomata response with whole-plant hydraulics and carbon balance. New Phytol 2023; 238:506-528. [PMID: 36377138 DOI: 10.1111/nph.18620] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Every existing optimal stomatal model uses photosynthetic carbon assimilation as a proxy for plant evolutionary fitness. However, assimilation and growth are often decoupled, making assimilation less ideal for representing fitness when optimizing stomatal conductance to water vapor and carbon dioxide. Instead, growth should be considered a closer proxy for fitness. We hypothesize stomata have evolved to maximize turgor-driven growth, instead of assimilation, over entire plants' lifetimes, improving their abilities to compete and reproduce. We develop a stomata model that dynamically maximizes whole-stem growth following principles from turgor-driven growth models. Stomata open to assimilate carbohydrates that supply growth and osmotically generate turgor, while stomata close to prevent losses of turgor and growth due to negative water potentials. In steady state, the growth optimization model captures realistic stomatal, growth, and carbohydrate responses to environmental cues, reconciles conflicting interpretations within existing stomatal optimization theories, and explains patterns of carbohydrate storage and xylem conductance observed during and after drought. Our growth optimization hypothesis introduces a new paradigm for stomatal optimization models, elevates the role of whole-plant carbon use and carbon storage in stomatal functioning, and has the potential to simultaneously predict gross productivity, net productivity, and plant mortality through a single, consistent modeling framework.
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Affiliation(s)
- Aaron Potkay
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA
- Saint Anthony Falls Laboratory, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA
| | - Xue Feng
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA
- Saint Anthony Falls Laboratory, University of Minnesota, Twin Cities, Minneapolis, MN, 55455, USA
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35
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Bortolami G, Ferrer N, Baumgartner K, Delzon S, Gramaje D, Lamarque LJ, Romanazzi G, Gambetta GA, Delmas CEL. Esca grapevine disease involves leaf hydraulic failure and represents a unique premature senescence process. Tree Physiol 2023; 43:441-451. [PMID: 36416206 DOI: 10.1093/treephys/tpac133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 10/05/2022] [Accepted: 11/16/2022] [Indexed: 05/03/2023]
Abstract
Xylem anatomy may change in response to environmental or biotic stresses. Vascular occlusion, an anatomical modification of mature xylem, contributes to plant resistance and susceptibility to different stresses. In woody organs, xylem occlusions have been examined as part of the senescence process, but their presence and function in leaves remain obscure. In grapevine, many stresses are associated with premature leaf senescence inducing discolorations and scorched tissue in leaves. However, we still do not know whether the leaf senescence process follows the same sequence of physiological events and whether leaf xylem anatomy is affected in similar ways. In this study, we quantified vascular occlusions in midribs from leaves with symptoms of the grapevine disease esca, magnesium deficiency and autumn senescence. We found higher amounts of vascular occlusions in leaves with esca symptoms (in 27% of xylem vessels on average), whereas the leaves with other symptoms (as well as the asymptomatic controls) had far fewer occlusions (in 3% of vessels). Therefore, we assessed the relationship between xylem occlusions and esca leaf symptoms in four different countries (California in the USA, France, Italy and Spain) and eight different cultivars. We monitored the plants over the course of the growing season, confirming that vascular occlusions do not evolve with symptom age. Finally, we investigated the hydraulic integrity of leaf xylem vessels by optical visualization of embolism propagation during dehydration. We found that the occlusions lead to hydraulic dysfunction mainly in the peripheral veins compared with the midribs in esca symptomatic leaves. These results open new perspectives on the role of vascular occlusions during the leaf senescence process, highlighting the uniqueness of esca leaf symptoms and its consequence on leaf physiology.
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Affiliation(s)
- Giovanni Bortolami
- INRAE, BSA, ISVV, SAVE, 33882 Villenave d'Ornon, France
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, The Netherlands
| | | | - Kendra Baumgartner
- United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, Davis, CA 95616, USA
| | | | - David Gramaje
- Institute of Grapevine and Wine Sciences (ICVV), Spanish National Research Council (CSIC), University of La Rioja and Government of La Rioja, Logroño 26007, Spain
| | - Laurent J Lamarque
- Univ. Bordeaux, INRAE, BIOGECO, 33615 Pessac, France
- Département des Sciences de l'Environnement, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, G9A 5H7, Canada
| | - Gianfranco Romanazzi
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Gregory A Gambetta
- EGFV, Bordeaux-Sciences Agro, INRAE, Université de Bordeaux, ISVV, 33882 Villenave d'Ornon, France
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36
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Guo L, Liu Y, Liu L, Yin P, Liu C, Li J. Study of the mechanism of embolism removal in xylem vessels by using microfluidic devices. Lab Chip 2023; 23:737-747. [PMID: 36594973 DOI: 10.1039/d2lc00945e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Determining the mechanism that effects embolism repair in the xylem vessels of plants is of great significance in predicting plant distribution and the screening of drought-resistant plants. However, the mechanism of perforation plates of xylem vessels in the acceleration of embolism repair is still not clear by using conventional methods of anatomy and visualization technology. Microfluidic devices have shown their ability to simulate physiological environments and conduct quantitative experiments. This work proposes a biomimetic microfluidic device to study the mechanism of perforation plates of xylem vessels in the acceleration of embolism repair. The results proffered that the perforation plates increase the rate of embolism removal by increasing the pressure differential through the vessel, and the rate of embolism removal is related to the structural parameters of the perforation plate. A combination of the perforation size, the vessel diameter and the perforation plate angle can be optimised to generate higher pressure differentials, which can accelerate the process of embolism repair. This work provides a new method for studying the mechanism of microstructures of natural plants. Furthermore, the mechanism that perforation plates accelerate embolism repair was applied to an electrochemical flow sensor for online determination of heavy metal ions. Test results of this application indicate that the mechanism can be applied in the engineering field to solve the problems of reduced sensitivity of devices, inaccuracy of analysis results and poor reaction performance caused by bubbles that are generated or introduced easily in microdevices, which paves the way for applying the theory to engineering.
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Affiliation(s)
- Lihua Guo
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
| | - Yuanchang Liu
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Li Liu
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
| | - Penghe Yin
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
| | - Chong Liu
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
| | - Jingmin Li
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
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37
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Partelli-Feltrin R, Smith AMS, Adams HD, Thompson RA, Kolden CA, Yedinak KM, Johnson DM. Death from hunger or thirst? Phloem death, rather than xylem hydraulic failure, as a driver of fire-induced conifer mortality. New Phytol 2023; 237:1154-1163. [PMID: 36052762 DOI: 10.1111/nph.18454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
Disruption of photosynthesis and carbon transport due to damage to the tree crown and stem cambial cells, respectively, can cause tree mortality. It has recently been proposed that fire-induced dysfunction of xylem plays an important role in tree mortality. Here, we simultaneously tested the impact of a lethal fire dose on nonstructural carbohydrates (NSCs) and xylem hydraulics in Pinus ponderosa saplings. Saplings were burned with a known lethal fire dose. Nonstructural carbohydrates were assessed in needles, main stems, roots and whole plants, and xylem hydraulic conductivity was measured in the main stems up to 29 d postfire. Photosynthesis and whole plant NSCs declined postfire. Additionally, all burned saplings showed 100% phloem/cambium necrosis, and roots of burned saplings had reduced NSCs compared to unburned and defoliated saplings. We further show that, contrary to patterns observed with NSCs, water transport was unchanged by fire and there was no evidence of xylem deformation in saplings that experienced a lethal dose of heat from fire. We conclude that phloem and cambium mortality, and not hydraulic failure, were probably the causes of death in these saplings. These findings advance our understanding of the physiological response to fire-induced injuries in conifer trees.
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Affiliation(s)
| | - Alistair M S Smith
- Department of Forest, Rangeland, and Fire Sciences, University of Idaho, Moscow, ID, 83844, USA
- Department of Earth and Spatial Sciences, University of Idaho, Moscow, ID, 83844, USA
| | - Henry D Adams
- School of Environment, Washington State University, Pullman, WA, 99164-2812, USA
| | - R Alex Thompson
- School of Environment, Washington State University, Pullman, WA, 99164-2812, USA
| | - Crystal A Kolden
- Gallo School of Management, University of California Merced, Merced, CA, 95343, USA
| | - Kara M Yedinak
- US Forest Service Research and Development, Madison, WI, 53726-2366, USA
| | - Daniel M Johnson
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA
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38
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Mantova M, Cochard H, Burlett R, Delzon S, King A, Rodriguez-Dominguez CM, Ahmed MA, Trueba S, Torres-Ruiz JM. On the path from xylem hydraulic failure to downstream cell death. New Phytol 2023; 237:793-806. [PMID: 36305207 DOI: 10.1111/nph.18578] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Xylem hydraulic failure (HF) has been identified as a ubiquitous factor in triggering drought-induced tree mortality through the damage induced by the progressive dehydration of plant living cells. However, fundamental evidence of the mechanistic link connecting xylem HF to cell death has not been identified yet. The main aim of this study was to evaluate, at the leaf level, the relationship between loss of hydraulic function due to cavitation and cell death under drought conditions and discern how this relationship varied across species with contrasting resistances to cavitation. Drought was induced by withholding water from potted seedlings, and their leaves were sampled to measure their relative water content (RWC) and cell mortality. Vulnerability curves to cavitation at the leaf level were constructed for each species. An increment in cavitation events occurrence precedes the onset of cell mortality. A variation in cells tolerance to dehydration was observed along with the resistance to cavitation. Overall, our results indicate that the onset of cellular mortality occurs at lower RWC than the one for cavitation indicating the role of cavitation in triggering cellular death. They also evidenced a critical RWC for cellular death varying across species with different cavitation resistance.
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Affiliation(s)
- Marylou Mantova
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Hervé Cochard
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Régis Burlett
- Université Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Sylvain Delzon
- Université Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Andrew King
- Synchrotron SOLEIL, L'Orme des Merisiers, 91190, Gif-sur-Yvette cedex, France
| | - Celia M Rodriguez-Dominguez
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, 10, 41012, Sevilla, Spain
| | - Mutez A Ahmed
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440, Bayreuth, Germany
- Department of Land, Air and Water Resources, University of California Davis, Davis, CA, 95616, USA
| | | | - José M Torres-Ruiz
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
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39
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Fuenzalida TI, Blacker MJ, Turner M, Sheppard A, Ball MC. Foliar water uptake enables embolism removal in excised twigs of Avicennia marina. New Phytol 2023; 237:1136-1145. [PMID: 36372990 DOI: 10.1111/nph.18613] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
Embolism refilling is thought to require relaxation of xylem tension, and it is unclear whether and how tall trees or plants growing in arid or saline soils recover from embolism. We tested whether foliar water uptake could enable embolism refilling in dehydrated twigs of the grey mangrove (Avicennia marina). Four dehydrated twigs were imaged by laboratory-based micro-computed tomography before and after wetting leaves. Emboli were observed in dehydrated stems and leaves. Embolism decreased with increasing distance from the cut end of stems, suggesting that stem emboli were caused by cutting. A significant (P = 0.026) c. 80% reduction in the embolised area was observed in leaves between the start and the end of the experiment (29 ± 10 h after wetting). Embolus diameter was unaffected by wetting. Embolism refilling occurred slowly, in stems embolised by cutting and leaves embolised by cutting and/or dehydration. The lack of response of embolus diameter to wetting suggests that capillarity was not the main mechanism for refilling. Results show that excised twigs of A. marina are able to recover from embolism by absorption of atmospheric water and call for studies under natural conditions.
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Affiliation(s)
- Tomás I Fuenzalida
- Plant Science Division, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
| | - Matthew J Blacker
- Department of Quantum Science, Research School of Physics, Australian National University, Canberra, ACT, 2601, Australia
| | - Michael Turner
- Department of Applied Mathematics, Research School of Physics, Australian National University, Canberra, ACT, 2601, Australia
| | - Adrian Sheppard
- Department of Applied Mathematics, Research School of Physics, Australian National University, Canberra, ACT, 2601, Australia
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
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40
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Gebauer R, Urban J, Volařík D, Matoušková M, Vitásek R, Houšková K, Hurt V, Pantová P, Polívková T, Plichta R. Does leaf gas exchange correlate with petiole xylem structural traits in Ulmus laevis seedlings under well-watered and drought stress conditions? Tree Physiol 2022; 42:2534-2545. [PMID: 35866300 DOI: 10.1093/treephys/tpac082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
Several studies have shown that petiole xylem structure could be an important predictor of leaf gas exchange capacity, but the question of how petiole xylem structure relates to leaf gas exchange under different environment conditions remains unresolved. Moreover, knowledge of the amount of leaf gas exchange and structural variation that exists within a single species is also limited. In this study, we investigated the intraspecies coordination of leaf gas exchange and petiole xylem traits in 2-year-old seedlings of Ulmus laevis Pall. under well-watered and drought conditions. It was found that all studied petiole xylem traits of the elm seedlings were positively correlated with each other. This shows that the development of petiole xylem structure is internally well-coordinated. Nevertheless, the lower correlation coefficients between some petiole xylem traits indicate that the coordination is also individually driven. Drought stress reduced all studied leaf gas exchange traits and significantly increased intraspecies variation. In addition, drought stress also shifted the relationships between physiological traits and exhibited more structure-function relationships. This indicates the importance of petiole xylem structure in dictating water loss during drought stress and could partly explain the inconsistencies between leaf structure-function relationships studied under optimal conditions. Although several structure-function traits were related, the wide ranges of correlation coefficients indicate that the internal coordination of these traits substantially differs between individual elm seedlings. These findings are very important in the context of expected climatic change, as some degree of intraspecies variation in structure-function relationships could ensure the survival of some individuals under different environmental conditions.
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Affiliation(s)
- Roman Gebauer
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Josef Urban
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
- Department of Ecology and Environmental Study, Siberian Federal University, Krasnoyarsk, 79 Svobodny prospect, 66004, Russia
| | - Daniel Volařík
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Marie Matoušková
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Roman Vitásek
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Kateřina Houšková
- Department of Silviculture, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Václav Hurt
- The Czech Republic Nursery Association, z.s., Wolkerova 37/17, 779 00 Olomouc, Czech Republic
| | - Petra Pantová
- Department of Silviculture, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Terezie Polívková
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
| | - Roman Plichta
- Department of Forest Botany, Dendrology and Geobiocoenology, Mendel University in Brno, Zemědělská 3, 61300 Brno, Czech Republic
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41
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Kahmen A, Basler D, Hoch G, Link RM, Schuldt B, Zahnd C, Arend M. Root water uptake depth determines the hydraulic vulnerability of temperate European tree species during the extreme 2018 drought. Plant Biol (Stuttg) 2022; 24:1224-1239. [PMID: 36219537 DOI: 10.1111/plb.13476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
We took advantage of the European 2018 drought and assessed the mechanisms causing differences in drought vulnerability among mature individuals of nine co-occurring tree species at the Swiss Canopy Crane II site in Switzerland. Throughout the drought we monitored leaf water status and determined native embolism formation in the canopy of the trees as indicators of drought vulnerability. We also determined hydraulic vulnerability thresholds (Ψ12 -, Ψ50 - and Ψ88 -values), corresponding hydraulic safety margins (HSMs) and carbohydrate reserves for all species as well as total average leaf area per tree, and used stable isotopes to assess differences in root water uptake depth among the nine species as variables predicting differences in drought vulnerability among species. Marked differences in drought vulnerability were observed among the nine tree species. Six species maintained their water potentials above hydraulic thresholds, while three species, Fagus sylvatica, Carpinus betulus and Picea abies, were pushed beyond their hydraulic thresholds and showed loss of hydraulic conductivity in their canopies at the end of the drought. Embolism resistance thresholds and associated HSMs did not explain why the co-existing species differed in their drought vulnerability, neither did their degree of isohydry, nor their regulation of carbohydrate reserves. Instead, differences in structural-morphological traits, in particular root water uptake depth, were associated with the risk of reaching hydraulic vulnerability thresholds and embolism formation among the nine species. Our study shows that structural-morphological traits, such as root water uptake depth, determine how quickly different species approach hydraulic vulnerability thresholds during a drought event and can thus explain species differences in drought vulnerability among mature field-grown trees.
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Affiliation(s)
- A Kahmen
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
| | - D Basler
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - G Hoch
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
| | - R M Link
- Ecophysiology and Vegetation Ecology, Universität Würzburg, Würzburg, Germany
| | - B Schuldt
- Ecophysiology and Vegetation Ecology, Universität Würzburg, Würzburg, Germany
| | - C Zahnd
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
| | - M Arend
- Department of Environmental Sciences - Botany, University of Basel, Basel, Switzerland
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42
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Petruzzellis F, Tordoni E, Di Bonaventura A, Tomasella M, Natale S, Panepinto F, Bacaro G, Nardini A. Turgor loss point and vulnerability to xylem embolism predict species-specific risk of drought-induced decline of urban trees. Plant Biol (Stuttg) 2022; 24:1198-1207. [PMID: 34704333 PMCID: PMC10078640 DOI: 10.1111/plb.13355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Increasing frequency and severity of drought events is posing risks to trees' health, including those planted in urban settlements. Drought-induced decline of urban trees negatively affects ecosystem services of urban green spaces and implies cost for maintenance and removal of plants. We aimed at identifying physiological traits that can explain and predict the species-specific vulnerability to climate change in urban habitats. We assessed the relationships between long-term risk of decline of different tree species in a medium-sized town and their key indicators of drought stress tolerance, i.e. turgor loss point (TLP) and vulnerability to xylem embolism (P50 ). Starting from 2012, the study area experienced several summer seasons with positive anomalies of temperature and negative anomalies of precipitation. This trend was coupled with increasing percentages of urban trees showing signs of crown die-back and mortality. The species-specific risk of decline was higher for species with less negative TLP and P50 values. The relationship between species-specific risk of climate change-induced decline of urban trees and key physiological indicators of drought tolerance confirms findings obtained in natural forests and highlights that TLP and P50 are useful indicators for species selection for tree plantation in towns, to mitigate negative impacts of climate change.
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Affiliation(s)
- F. Petruzzellis
- Dipartimento di Scienze della VitaUniversità di TriesteTriesteItalia
- Dipartimento di Scienze agroalimentari, ambientali e animaliUniversità di UdineUdineItalia
| | - E. Tordoni
- Dipartimento di Scienze della VitaUniversità di TriesteTriesteItalia
- Institute of Ecology and Earth ScienceUniversity of TartuTartuEstonia
| | - A. Di Bonaventura
- Dipartimento di Scienze della VitaUniversità di TriesteTriesteItalia
| | - M. Tomasella
- Dipartimento di Scienze della VitaUniversità di TriesteTriesteItalia
| | - S. Natale
- Dipartimento di Scienze della VitaUniversità di TriesteTriesteItalia
| | - F. Panepinto
- Unità Tecnica Alberature e ParchiServizio Strade e Verde PubblicoComune di TriesteTriesteItalia
| | - G. Bacaro
- Dipartimento di Scienze della VitaUniversità di TriesteTriesteItalia
| | - A. Nardini
- Dipartimento di Scienze della VitaUniversità di TriesteTriesteItalia
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43
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Lens F, Gleason SM, Bortolami G, Brodersen C, Delzon S, Jansen S. Functional xylem characteristics associated with drought-induced embolism in angiosperms. New Phytol 2022; 236:2019-2036. [PMID: 36039697 DOI: 10.1111/nph.18447] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 08/03/2022] [Indexed: 06/15/2023]
Abstract
Hydraulic failure resulting from drought-induced embolism in the xylem of plants is a key determinant of reduced productivity and mortality. Methods to assess this vulnerability are difficult to achieve at scale, leading to alternative metrics and correlations with more easily measured traits. These efforts have led to the longstanding and pervasive assumed mechanistic link between vessel diameter and vulnerability in angiosperms. However, there are at least two problems with this assumption that requires critical re-evaluation: (1) our current understanding of drought-induced embolism does not provide a mechanistic explanation why increased vessel width should lead to greater vulnerability, and (2) the most recent advancements in nanoscale embolism processes suggest that vessel diameter is not a direct driver. Here, we review data from physiological and comparative wood anatomy studies, highlighting the potential anatomical and physicochemical drivers of embolism formation and spread. We then put forward key knowledge gaps, emphasising what is known, unknown and speculation. A meaningful evaluation of the diameter-vulnerability link will require a better mechanistic understanding of the biophysical processes at the nanoscale level that determine embolism formation and spread, which will in turn lead to more accurate predictions of how water transport in plants is affected by drought.
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Affiliation(s)
- Frederic Lens
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA, Leiden, the Netherlands
- Leiden University, Institute of Biology Leiden, Plant Sciences, Sylviusweg 72, 2333 BE, Leiden, the Netherlands
| | - Sean M Gleason
- Water Management and Systems Research Unit, United States Department of Agriculture, Agricultural Research Service, Fort Collins, CO, 80526, USA
| | - Giovanni Bortolami
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA, Leiden, the Netherlands
| | - Craig Brodersen
- School of the Environment, Yale University, New Haven, CT, 06511, USA
| | - Sylvain Delzon
- University of Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, D-89081, Ulm, Germany
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44
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Fan DY, Dang QL, Yang XF, Liu XM, Wang JY, Zhang SR. Nitrogen deposition increases xylem hydraulic sensitivity but decreases stomatal sensitivity to water potential in two temperate deciduous tree species. Sci Total Environ 2022; 848:157840. [PMID: 35934026 DOI: 10.1016/j.scitotenv.2022.157840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/22/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Although the effects of nitrogen deposition on tree water relations are studied extensively, its impact on the relative sensitivities of stomatal and xylem hydraulic conductance to vapor pressure deficit and water potential is still poorly understood. This study investigated the effects of a 7-year N deposition treatment on the responses of leaf water relations and sensitivity of canopy stomatal conductance to vapor pressure deficit (VPD) and water potential, as well as the sensitivity of branch hydraulic conductance to water potential in a dominant tree species (Quercus wutaishanica) and an associated tree species (Acer mono) in a temperate forest. It was found that the N deposition increased stomatal sensitivity to VPD, decreased stomatal sensitivity to water potential, and increased the vulnerability of the hydraulic system to cavitation in both species. The standardized stomatal sensitivity to VPD, however, was not affected by the N deposition, indicating that the stomata maintained the ability to regulate the water balance under nitrogen deposition condition. Although the increased stomatal sensitivity to VPD could compensate the decreased stomatal sensitivity to water potential to some extent, the combined response would increase the percentage loss of hydraulic conductivity (PLC) when 50 % loss in stomatal conductance occurred, particularly in the dominant species Q. wutaishanica. The result indicates that N deposition would increase the risk of hydraulic failure in those species if the soil and/or air becomes drier under future climate change scenarios. The results of the study can have significant implications on the modelling of ecosystem vulnerability to drought under the scenario of atmospheric nitrogen deposition.
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Affiliation(s)
- Da-Yong Fan
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China.
| | - Qing-Lai Dang
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON, Canada
| | - Xiao-Fang Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100096, China
| | - Xiao-Ming Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100096, China
| | - Jia-Yi Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China
| | - Shou-Ren Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100096, China.
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45
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Weithmann G, Paligi SS, Schuldt B, Leuschner C. Branch xylem vascular adjustments in European beech in response to decreasing water availability across a precipitation gradient. Tree Physiol 2022; 42:2224-2238. [PMID: 35861677 DOI: 10.1093/treephys/tpac080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
Crucial for the climate adaptation of trees is a xylem anatomical structure capable of adjusting to changing water regimes. Although species comparisons across climate zones have demonstrated anatomical change in response to altered water availability and tree height, less is known about the adaptability of tree vascular systems to increasing water deficits at the intraspecific level. Information on the between-population and within-population variability of xylem traits helps assessing a species' ability to cope with climate change. We investigated the variability of wood anatomical and related hydraulic traits in terminal branches of European beech (Fagus sylvatica L.) trees across a precipitation gradient (520-890 mm year-1) and examined the influence of climatic water balance (CWB), soil water capacity (AWC), neighborhood competition (CI), tree height and branch age on these traits. Furthermore, the relationship between xylem anatomical traits and embolism resistance (P50) was tested. Within-population trait variation was larger than between-population variation. Vessel diameter, lumen-to-sapwood area ratio and potential conductivity of terminal branches decreased with decreasing CWB, but these traits were not affected by AWC, whereas vessel density increased with an AWC decrease. In contrast, none of the studied anatomical traits were influenced by variation in tree height (21-34 m) or CI. Branch age was highly variable (2-22 years) despite equal diameter and position in the flow path, suggesting different growth trajectories in the past. Vessel diameter decreased, and vessel density increased, with increasing branch age, reflecting negative annual radial growth trends. Although vessel diameter was not related to P50, vessel grouping index and lumen-to-sapwood area ratio showed a weak, though highly significant, positive relationship to P50. We conclude that the xylem anatomy of terminal tree-top branches in European beech is modified in response to increasing climatic aridity and/or decreasing soil water availability, independent of a tree height effect.
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Affiliation(s)
- Greta Weithmann
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, 37073 Goettingen, Germany
| | - Sharath Shyamappa Paligi
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, 37073 Goettingen, Germany
| | - Bernhard Schuldt
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, 37073 Goettingen, Germany
- Ecophysiology and Vegetation Ecology, Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz, 97082 Würzburg, Germany
| | - Christoph Leuschner
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Goettingen, Untere Karspüle 2, 37073 Goettingen, Germany
- Centre for Biodiversity and Sustainable Land Use (CBL), University of Goettingen, 37075 Goettingen, Germany
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46
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Zlobin IE, Kartashov AV, Ivanov YV, Ivanova AI, Kuznetsov VV. Stem notching decreases stem hydraulic conductance but does not influence drought impacts and post-drought recovery in Scots pine and Norway spruce. Physiol Plant 2022; 174:e13813. [PMID: 36326172 DOI: 10.1111/ppl.13813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 06/16/2023]
Abstract
The tight connection between the deterioration of xylem function and plant mortality under drought is well recognized. However, a lack of mechanistic understanding of how substantial conductivity loss influences plant performance under drought and during post-drought recovery hinders our ability to model tree responses to drought stress. We artificially induced a loss of 50% of xylem conducting area in Scots pine and Norway spruce saplings by stem notching and investigated plant performance under drought and during post-drought recovery. Plant mortality, xylem hydraulic conductivity, leaf water status and stomatal conductance were measured. We observed no preferential mortality of top plant parts (above the notches) compared to basal plant parts (below the notches), and no consistent trend in hydraulic conductivity loss was observed between top and basal parts of dying plants. Stem hydraulic conductivity, water status of the needles and stomatal conductance changed similarly between the top and basal parts during drought and post-drought recovery, which indicated the substantial hydraulic overcapacity of the stems. The recovery of stomatal conductance demonstrated prominent hysteresis due to non-hydraulic stomatal limitations. The results obtained are highly important for modelling the influence of plant hydraulic impairment on plant performance under drought and during post-drought recovery.
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Affiliation(s)
- Ilya E Zlobin
- K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia
| | | | - Yury V Ivanov
- K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia
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47
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Sun Q. Structural variation and spatial polysaccharide profiling of intervessel pit membranes in grapevine. Ann Bot 2022; 130:595-609. [PMID: 35869610 PMCID: PMC9510951 DOI: 10.1093/aob/mcac096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND AIMS Intervessel pit membranes (PMs) are important cell wall structures in the vessel system that may impact a plant's water transport and its susceptibility to vascular diseases. Functional roles of intervessel PMs largely depend on their structure and polysaccharide composition, which are the targets of this study. METHODS With grapevine used as a model plant, this study applied an immunogold-scanning electron microscopy technique to simultaneously analyse at high resolution intervessel PM structures and major pectic and hemicellulosic polysaccharides that make up intervessel PMs. KEY RESULTS Intervessel PMs in functional xylem showed significant structural variation, with about 90 % of them being structurally intact with smooth or relatively smooth surfaces and the remaining 10 % with progressively degraded structures. The results also elucidated details of the removal process of cell wall materials from the intervessel PM surface toward its depth during its natural degradation. Four groups of pectic and hemicellulosic polysaccharides were immunolocalized in intervessel PMs and differed in their spatial distribution and abundance. Weakly methyl-esterified homogalacturonans (WMe-HGs, detected by JIM5) were abundant in the surface layer, heavily methyl-esterified homogalacturonans (HMe-HGs, detected by JIM7) and xylans detected by CCRC-M140 were mostly found in deeper layers, and fucosylated xyloglucans (F-XyGs, detected by CCRC-M1) were more uniformly distributed at different depths of the intervessel PM. CONCLUSIONS Intervessel PMs displayed diverse structural variations in grapevine. They contained certain major groups of pectic and hemicellulosic polysaccharides with different spatial distributions and abundance. This information is crucial to reveal the polysaccharide profiling of the primary cell wall and to understand the roles of intervessel PMs in the regulation of water transport as well as in a plant's susceptibility to vascular diseases.
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48
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Valdovinos-Ayala J, Robles C, Fickle JC, Pérez-de-Lis G, Pratt RB, Jacobsen AL. Seasonal patterns of increases in stem girth, vessel development, and hydraulic function in deciduous tree species. Ann Bot 2022; 130:355-365. [PMID: 35274669 PMCID: PMC9486900 DOI: 10.1093/aob/mcac032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND AIMS The onset of spring growth and vessel formation were examined within three deciduous woody plant species, Acer rubrum, Populus balsamifera ssp. trichocarpa and Quercus rubra. We were broadly interested in the lag between the onset of girth expansion and the formation of mature and hydraulically conductive vessels within the new xylem. METHODS Dendrometers were installed on 20 trees (6-7 per species), and expansion of both bole and distal stems was monitored throughout the growing season in a common garden. For each species, four to six distal stems were harvested every other week for anatomical examination of vessel formation. Additionally, for Populus and Quercus, hydraulic conductivity measurements and active xylem staining were completed on all stem samples. KEY RESULTS For all three species, the timing of girth expansion was similar. Expansion of distal branches occurred 12-37 d earlier than that of the bole. Vessel formation initiated several weeks prior to leaf-out, but no new earlywood vessels were mature at the time of bud break for Acer and Populus and only a few were present in Quercus. Initial stem girth expansion occurred 2 to >6 weeks before the maturation of the first current-year vessels, and there was an additional delay of up to 4 weeks before mature vessels became hydraulically functional. Hydraulic conductivity was strongly correlated with the number and diameter of stained vessels. CONCLUSIONS Bud break and leaf expansion relied predominantly on water supplied by vessels formed during prior seasons. Early-season activity is likely affected by the function of older xylem vessels and the environmental factors that influence their structure and function. Understanding the functional lifespan of vessels and the varying contributions of new and older vessels to conductivity are critical to understanding of the phenology and vascular function of long-lived woody plants in response to changing climates.
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Affiliation(s)
| | - Catherine Robles
- Department of Biology, California State University, Bakersfield, CA, USA
| | - Jaycie C Fickle
- Department of Biology, California State University, Bakersfield, CA, USA
| | - Gonzalo Pérez-de-Lis
- Department of Biology, California State University, Bakersfield, CA, USA
- BIOAPLIC, Departamento de Botánica, EPSE, Universidade de Santiago de Compostela, Campus Terra, 27002 Lugo, Spain
| | - R Brandon Pratt
- Department of Biology, California State University, Bakersfield, CA, USA
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49
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Dória LC, Sonsin-Oliveira J, Rossi S, Marcati CR. Functional trade-offs in volume allocation to xylem cell types in 75 species from the Brazilian savanna Cerrado. Ann Bot 2022; 130:445-456. [PMID: 35863898 PMCID: PMC9486921 DOI: 10.1093/aob/mcac095] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/20/2022] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Xylem is a crucial tissue for plant survival, performing the functions of water transport, mechanical support and storage. Functional trade-offs are a result of the different assemblages of xylem cell types within a certain wood volume. We assessed how the volume allocated to different xylem cell types can be associated with wood functional trade-offs (hydraulics, mechanical and storage) in species from the Cerrado, the Brazilian savanna. We also assessed the xylem anatomical characters linked to wood density across species. METHODS We analysed cross-sections of branches collected from 75 woody species belonging to 42 angiosperm families from the Cerrado. We estimated the wood volume fraction allocated to different cell types and performed measurements of vessel diameter and wood density. KEY RESULTS The largest volume of wood is allocated to fibres (0.47), followed by parenchyma (0.33) and vessels (0.20). Wood density is positively correlated to cell wall (fibre and vessel wall), and negatively to the fractions of fibre lumen and gelatinous fibres. We observed a trade-off between hydraulics (vessel diameter) and mechanics (cell wall fraction), and between mechanics and storage (parenchyma fraction). The expected positive functional relationships between hydraulics (vessel diameter) and water and carbohydrate storage (parenchyma and fibre lumen fractions) were not detected, though larger vessels are linked to a larger wood volume allocated to gelatinous fibres. CONCLUSIONS Woody species from the Cerrado show evidence of functional trade-offs between water transport, mechanical support and storage. Gelatinous fibres might be potentially linked to water storage and release by their positive relationship to increased vessel diameter, thus replacing the functional role of parenchyma and fibre lumen cells. Species can profit from the increased mechanical strength under tension provided by the presence of gelatinous fibres, avoiding expensive investments in high wood density.
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Affiliation(s)
| | - Julia Sonsin-Oliveira
- Departamento de Biologia Vegetal, Programa de Pós-Graduação em Botânica, Instituto de Ciências Biológicas, Universidade de Brasilia (UnB), Brasília, DF, Brazil
| | - Sergio Rossi
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Carmen Regina Marcati
- Departamento de Ciência Florestal, Solos e Ambiente, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Agronômicas, Avenida Universitária, Botucatu, SP, Brazil
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Wang L, Dai Y, Zhang J, Meng P, Wan X. Xylem structure and hydraulic characteristics of deep roots, shallow roots and branches of walnut under seasonal drought. BMC Plant Biol 2022; 22:440. [PMID: 36104814 PMCID: PMC9472371 DOI: 10.1186/s12870-022-03815-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Despite the importance of root hydraulics, there is little research on the in situ dynamic responses of embolism formation and embolism repair of roots distributed in different soil depths in response to different water regimes. RESULTS The vessel diameter, hydraulic conductivity, and vulnerability to cavitation were in the order of deep root > shallow root > branch. The midday PLC of shallow root was the highest in the dry season, while the midday PLC of deep root slightly higher than that of branch with no significant difference in the two seasons. The capacity of embolism repair of roots was significantly greater than that of branch both in dry season and wet season. The xylem pressure was in the order of deep roots > shallow root > branch, and it was negative in most of the time for the latter two in the dry season, but positive for both of the roots during the observation period in the wet season. The NSC and starch content in roots were significantly higher than those in branches, especially in the dry season. In contrast, roots had lower content of soluble sugar. CONCLUSIONS The relatively stable water condition in soil, especially in the deep layers, is favorable for the development of larger-diameter vessels in root xylem, however it cannot prevent the root from forming embolism. The mechanism of embolism repair may be different in different parts of plants. Deep roots mainly depend on root pressure to refill the embolized vessels, while branches mainly depend on starch hydrolysis to soluble sugars to do the work, with shallow roots shifted between the two mechanisms in different moisture regimes. There is theoretically an obvious trade-off between conducting efficiency and safety over deep roots, shallow roots and branches. But in natural conditions, roots do not necessarily suffer more severe embolism than branches, maybe due to their root pressure-driven embolism repair and relatively good water conditions.
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Affiliation(s)
- Lin Wang
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, 030801, People's Republic of China
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Yongxin Dai
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, 030801, People's Republic of China
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Jinsong Zhang
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Ping Meng
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Xianchong Wan
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China.
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