1
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Silva LM, Pereira L, Kaack L, Guan X, Pfaff J, Trabi CL, Jansen S. The potential link between gas diffusion and embolism spread in angiosperm xylem: Evidence from flow-centrifuge experiments and modelling. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39119783 DOI: 10.1111/pce.15084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/19/2024] [Accepted: 07/27/2024] [Indexed: 08/10/2024]
Abstract
Understanding xylem embolism formation is challenging due to dynamic changes and multiphase interactions in conduits. Here, we hypothesise that embolism spread involves gas diffusion in xylem, and is affected by time. We measured hydraulic conductivity (Kh) in flow-centrifuge experiments over 1 h at a given pressure and temperature for stem samples of three angiosperm species. Temporal changes in Kh at 5, 22, and 35°C, and at various pressures were compared to modelled gas concentration changes in a recently embolised vessel in the centre of a centrifuge sample. Temporal changes in Kh were logarithmic and species-specific. Maximum relative increases of Kh between 6% and 40% happened at 22°C for low centrifugal speed (<3250 RPM), while maximum decreases between 41% and 61% occurred at higher speeds. These reductions in Kh were experimentally shown to be associated with a temporal increase of embolism at the centre of centrifuge samples, which was likely associated with gas concentration increases in recently embolized vessels. Although embolism is mostly pressure-driven, our experimental and modelled data indicate that time, conduit characteristics, and temperature are involved due to their potential role in gas diffusion. Gas diffusion, however, does not seem to cover the entire process of embolism spread.
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Affiliation(s)
| | | | - Lucian Kaack
- Institute of Botany, Ulm University, Ulm, Germany
- Botanical Garden of Ulm University, Hans-Krebs-Weg, Ulm, Germany
| | - Xinyi Guan
- Institute of Botany, Ulm University, Ulm, Germany
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China
| | - Jonas Pfaff
- Institute of Botany, Ulm University, Ulm, Germany
| | - Christophe L Trabi
- Institute of Botany, Ulm University, Ulm, Germany
- Core Facility Confocal and Multiphoton Microscopy, Ulm University, Ulm, Germany
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2
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Roth-Nebelsick A, Konrad W. Modeling and Analyzing Xylem Vulnerability to Embolism as an Epidemic Process. Methods Mol Biol 2024; 2722:17-34. [PMID: 37897597 DOI: 10.1007/978-1-0716-3477-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/30/2023]
Abstract
Xylem vulnerability to embolism can be quantified by "vulnerability curves" (VC) that are obtained by subjecting wood samples to increasingly negative water potential and monitoring the progressive loss of hydraulic conductivity. VC are typically sigmoidal, and various approaches are used to fit the experimentally obtained VC data for extracting benchmark data of vulnerability to embolism. In addition to such empirical methods, mechanistic approaches to calculate embolism propagation are epidemic modeling and network theory. Both describe the transmission of "objects" (in this case, the transmission of gas) between interconnected elements. In network theory, a population of interconnected elements is described by graphs in which objects are represented by vertices or nodes and connections between these objections as edges linking the vertices. A graph showing a population of interconnected xylem conduits represents an "individual" wood sample that allows spatial tracking of embolism propagation. In contrast, in epidemic modeling, the transmission dynamics for a population that is subdivided into infection-relevant groups is calculated by an equation system. For this, embolized conduits are considered to be "infected," and the "infection" is the transmission of gas from embolized conduits to their still water-filled neighbors. Both approaches allow for a mechanistic simulation of embolism propagation.
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Affiliation(s)
| | - Wilfried Konrad
- Department of Geosciences, University of Tübingen, Tübingen, Germany.
- Institute of Botany, Technical University of Dresden, Dresden, Germany.
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3
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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. THE NEW PHYTOLOGIST 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] [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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4
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Johnson DM, Katul G, Domec J. Catastrophic hydraulic failure and tipping points in plants. PLANT, CELL & ENVIRONMENT 2022; 45:2231-2266. [PMID: 35394656 PMCID: PMC9544843 DOI: 10.1111/pce.14327] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/14/2022] [Accepted: 03/20/2022] [Indexed: 06/12/2023]
Abstract
Water inside plants forms a continuous chain from water in soils to the water evaporating from leaf surfaces. Failures in this chain result in reduced transpiration and photosynthesis and are caused by soil drying and/or cavitation-induced xylem embolism. Xylem embolism and plant hydraulic failure share several analogies to 'catastrophe theory' in dynamical systems. These catastrophes are often represented in the physiological and ecological literature as tipping points when control variables exogenous (e.g., soil water potential) or endogenous (e.g., leaf water potential) to the plant are allowed to vary on time scales much longer than time scales associated with cavitation events. Here, plant hydraulics viewed from the perspective of catastrophes at multiple spatial scales is considered with attention to bubble expansion within a xylem conduit, organ-scale vulnerability to embolism, and whole-plant biomass as a proxy for transpiration and hydraulic function. The hydraulic safety-efficiency tradeoff, hydraulic segmentation and maximum plant transpiration are examined using this framework. Underlying mechanisms for hydraulic failure at fine scales such as pit membranes and cell-wall mechanics, intermediate scales such as xylem network properties and at larger scales such as soil-tree hydraulic pathways are discussed. Understudied areas in plant hydraulics are also flagged where progress is urgently needed.
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Affiliation(s)
- Daniel M. Johnson
- Warnell School of Forestry and Natural ResourcesUniversity of GeorgiaAthensGeorgiaUSA
| | - Gabriel Katul
- Department of Civil and Environmental EngineeringDuke UniversityDurhamNorth CarolinaUSA
- Nicholas School of the EnvironmentDuke UniversityDurhamNorth CarolinaUSA
| | - Jean‐Christophe Domec
- Nicholas School of the EnvironmentDuke UniversityDurhamNorth CarolinaUSA
- Department of ForestryBordeaux Sciences Agro, UMR INRAE‐ISPA 1391GradignanFrance
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5
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Song J, Trueba S, Yin XH, Cao KF, Brodribb TJ, Hao GY. Hydraulic vulnerability segmentation in compound-leaved trees: Evidence from an embolism visualization technique. PLANT PHYSIOLOGY 2022; 189:204-214. [PMID: 35099552 PMCID: PMC9070814 DOI: 10.1093/plphys/kiac034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/27/2021] [Indexed: 05/11/2023]
Abstract
The hydraulic vulnerability segmentation (HVS) hypothesis implies the existence of differences in embolism resistance between plant organs along the xylem pathway and has been suggested as an adaptation allowing the differential preservation of more resource-rich tissues during drought stress. Compound leaves in trees are considered a low-cost means of increasing leaf area and may thus be expected to show evidence of strong HVS, given the tendency of compound-leaved tree species to shed their leaf units during drought. However, the existence and role of HVS in compound-leaved tree species during drought remain uncertain. We used an optical visualization technique to estimate embolism occurrence in stems, petioles, and leaflets of shoots in two compound-leaved tree species, Manchurian ash (Fraxinus mandshurica) and Manchurian walnut (Juglans mandshurica). We found higher (less negative) water potentials corresponding to 50% loss of conductivity (P50) in leaflets and petioles than in stems in both species. Overall, we observed a consistent pattern of stem > petiole > leaflet in terms of xylem resistance to embolism and hydraulic safety margins (i.e. the difference between mid-day water potential and P50). The coordinated variation in embolism vulnerability between organs suggests that during drought conditions, trees benefit from early embolism and subsequent shedding of more expendable organs such as leaflets and petioles, as this provides a degree of protection to the integrity of the hydraulic system of the more carbon costly stems. Our results highlight the importance of HVS as an adaptive mechanism of compound-leaved trees to withstand drought stress.
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Affiliation(s)
- Jia Song
- CAS Key Laboratory of Forest Ecology and Management & Key Laboratory of Terrestrial Ecosystem Carbon Neutrality Liaoning Province, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China
- School of Environmental and Geographical Science, Shanghai Normal University, Shanghai 200234, China
- Yangtze River Delta National Observatory of Wetland Ecosystem, Shanghai Normal University, Shanghai 200234, China
| | - Santiago Trueba
- University of Bordeaux, INRAE, BIOGECO, 33615 Pessac, France
| | - Xiao-Han Yin
- CAS Key Laboratory of Forest Ecology and Management & Key Laboratory of Terrestrial Ecosystem Carbon Neutrality Liaoning Province, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China
| | - Kun-Fang Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, and College of Forestry, Guangxi University, Nanning, Guangxi 530004, China
| | - Timothy J Brodribb
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
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Buttó V, Millan M, Rossi S, Delagrange S. Contrasting Carbon Allocation Strategies of Ring-Porous and Diffuse-Porous Species Converge Toward Similar Growth Responses to Drought. FRONTIERS IN PLANT SCIENCE 2021; 12:760859. [PMID: 34975943 PMCID: PMC8716880 DOI: 10.3389/fpls.2021.760859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Extreme climatic events that are expected under global warming expose forest ecosystems to drought stress, which may affect the growth and productivity. We assessed intra-annual growth responses of trees to soil water content in species belonging to different functional groups of tree-ring porosity. We pose the hypothesis that species with contrasting carbon allocation strategies, which emerge from different relationships between wood traits and canopy architecture, display divergent growth responses to drought. We selected two diffuse-porous species (Acer saccharum and Betula alleghaniensis) and two ring-porous species (Quercus rubra and Fraxinus americana) from the mixed forest of Quebec (Canada). We measured anatomical wood traits and canopy architecture in eight individuals per species and assessed tree growth sensitivity to water balance during 2008-2017 using the standardized precipitation evapotranspiration index (SPEI). Stem elongation in diffuse-porous species mainly depended upon the total number of ramifications and hydraulic diameter of the tree-ring vessels. In ring-porous species, stem elongation mainly depended upon the productivity of the current year, i.e., number of vessels and basal area increment. Diffuse-porous and ring-porous species had similar responses to soil water balance. The effect of soil water balance on tree growth changed during the growing season. In April, decreasing soil temperature linked to wet conditions could explain the negative relationship between SPEI and tree growth. In late spring, greater water availability affected carbon partitioning, by promoting the formation of larger xylem vessels in both functional groups. Results suggest that timings and duration of drought events affect meristem growth and carbon allocation in both functional groups. Drought induces the formation of fewer xylem vessels in ring-porous species, and smaller xylem vessels in diffuse-porous species, the latter being also prone to a decline in stem elongation due to a reduced number of ramifications. Indeed, stem elongation of diffuse-porous species is influenced by environmental conditions of the previous year, which determine the total number of ramifications during the current year. Drought responses in different functional groups are thus characterized by different drivers, express contrasting levels of resistance or resilience, but finally result in an overall similar loss of productivity.
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Affiliation(s)
- Valentina Buttó
- Département des Sciences Naturelles, Institut des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, Ripon, QC, Canada
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Mathilde Millan
- Département des Sciences Naturelles, Institut des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, Ripon, QC, Canada
| | - Sergio Rossi
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Sylvain Delagrange
- Département des Sciences Naturelles, Institut des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, Ripon, QC, Canada
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7
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Pratt RB, Tobin MF, Jacobsen AL, Traugh CA, De Guzman ME, Hayes CC, Toschi HS, MacKinnon ED, Percolla MI, Clem ME, Smith PT. Starch storage capacity of sapwood is related to dehydration avoidance during drought. AMERICAN JOURNAL OF BOTANY 2021; 108:91-101. [PMID: 33349932 DOI: 10.1002/ajb2.1586] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 09/22/2020] [Indexed: 05/26/2023]
Abstract
PREMISE The xylem tissue of plants performs three principal functions: transport of water, support of the plant body, and nutrient storage. Tradeoffs may arise because different structural requirements are associated with different functions or because suites of traits are under selection that relate to resource acquisition, use, and turnover. The structural and functional basis of xylem storage is not well established. We hypothesized that greater starch storage would be associated with greater sapwood parenchyma and reduced fibers, which would compromise resistance to xylem tensions during dehydration. METHODS We measured cavitation resistance, minimum water potential, starch content, and sapwood parenchyma and fiber area in 30 species of southern California chaparral shrubs (evergreen and deciduous). RESULTS We found that species storing greater starch within their xylem tended to avoid dehydration and were less cavitation resistant, and this was supported by phylogenetic independent contrasts. Greater sapwood starch was associated with greater parenchyma area and reduced fiber area. For species without living fibers, the associations with parenchyma were stronger, suggesting that living fibers may expand starch storage capacity while also contributing to the support function of the vascular tissue. Drought-deciduous species were associated with greater dehydration avoidance than evergreens. CONCLUSIONS Evolutionary forces have led to an association between starch storage and dehydration resistance as part of an adaptive suite of traits. We found evidence for a tradeoff between tissue mechanical traits and starch storage; moreover, the evolution of novel strategies, such as starch-storing living fibers, may mitigate the strength of this tradeoff.
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Affiliation(s)
- R Brandon Pratt
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Michael F Tobin
- University of Houston-Downtown, Department of Natural Sciences, One Main Street, Houston, Texas, 77002, USA
| | - Anna L Jacobsen
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Courtney A Traugh
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Mark E De Guzman
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Christine C Hayes
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Hayden S Toschi
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Evan D MacKinnon
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Marta I Percolla
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Michael E Clem
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
| | - Paul T Smith
- California State University, Bakersfield, Department of Biology, Bakersfield, California, 93311, USA
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8
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Wang DR, Venturas MD, Mackay DS, Hunsaker DJ, Thorp KR, Gore MA, Pauli D. Use of hydraulic traits for modeling genotype-specific acclimation in cotton under drought. THE NEW PHYTOLOGIST 2020; 228:898-909. [PMID: 32557592 PMCID: PMC7586954 DOI: 10.1111/nph.16751] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 06/07/2020] [Indexed: 06/11/2023]
Abstract
Understanding the genetic and physiological basis of abiotic stress tolerance under field conditions is key to varietal crop improvement in the face of climate variability. Here, we investigate dynamic physiological responses to water stress in silico and their relationships to genotypic variation in hydraulic traits of cotton (Gossypium hirsutum), an economically important species for renewable textile fiber production. In conjunction with an ecophysiological process-based model, heterogeneous data (plant hydraulic traits, spatially-distributed soil texture, soil water content and canopy temperature) were used to examine hydraulic characteristics of cotton, evaluate their consequences on whole plant performance under drought, and explore potential genotype × environment effects. Cotton was found to have R-shaped hydraulic vulnerability curves (VCs), which were consistent under drought stress initiated at flowering. Stem VCs, expressed as percent loss of conductivity, differed across genotypes, whereas root VCs did not. Simulation results demonstrated how plant physiological stress can depend on the interaction between soil properties and irrigation management, which in turn affect genotypic rankings of transpiration in a time-dependent manner. Our study shows how a process-based modeling framework can be used to link genotypic variation in hydraulic traits to differential acclimating behaviors under drought.
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Affiliation(s)
- Diane R. Wang
- Department of GeographyUniversity at BuffaloBuffaloNY14261USA
- Present address:
Department of AgronomyPurdue UniversityWest LafayetteIN47907USA
| | | | - D. Scott Mackay
- Department of GeographyUniversity at BuffaloBuffaloNY14261USA
| | | | - Kelly R. Thorp
- US Arid‐Land Agricultural Research CenterMaricopaAZ37860USA
| | - Michael A. Gore
- Plant Breeding and Genetics SectionSchool of Integrative Plant ScienceCornell UniversityIthacaNY14853USA
| | - Duke Pauli
- School of Plant SciencesUniversity of ArizonaTucsonAZ85721USA
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9
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Soriano D, Echeverría A, Anfodillo T, Rosell JA, Olson ME. Hydraulic traits vary as the result of tip-to-base conduit widening in vascular plants. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4232-4242. [PMID: 32219309 DOI: 10.1093/jxb/eraa157] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 03/26/2020] [Indexed: 06/10/2023]
Abstract
Plant hydraulic traits are essential metrics for characterizing variation in plant function, but they vary markedly with plant size and position in a plant. We explore the potential effect of conduit widening on variation in hydraulic traits along the stem. We examined three species that differ in conduit diameter at the stem base for a given height (Moringa oleifera, Casimiroa edulis, and Pinus ayacahuite). We made anatomical and hydraulic measurements at different distances from the stem tip, constructed vulnerability curves, and examined the safety-efficiency trade-off with height-standardized data. Our results showed that segment-specific hydraulic resistance varied predictably along the stem, paralleling changes in mean conduit diameter and total number of conduits. The Huber value and leaf specific conductivity also varied depending on the sampling point. Vulnerability curves were markedly less noisy with height standardization, making the vulnerability-efficiency trade-off clearer. Because conduits widen predictably along the stem, taking height and distance from the tip into account provides a way of enhancing comparability and interpretation of hydraulic traits. Our results suggest the need for rethinking hydraulic sampling for comparing plant functional differences and strategies across individuals.
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Affiliation(s)
- Diana Soriano
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, CP, CDMX, México
| | - Alberto Echeverría
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, CP, CDMX, México
| | - Tommaso Anfodillo
- Department Territorio e Sistemi Agro-Forestali, University of Padova, Legnaro (PD), Italy
| | - Julieta A Rosell
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, CDMX, México
| | - Mark E Olson
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, CP, CDMX, México
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10
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Zhao H, Jiang Z, Ma J, Cai J. What causes the differences in cavitation resistance of two shrubs? Wood anatomical explanations and reliability testing of vulnerability curves. PHYSIOLOGIA PLANTARUM 2020; 169:156-168. [PMID: 31828790 DOI: 10.1111/ppl.13059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 12/09/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
Relationships between xylem anatomical traits and cavitation resistance have always been a major content of plant hydraulics. To know how plants cope with drought, it is extremely important to acquire detailed knowledge about xylem anatomical traits and assess the cavitation resistance accurately. This study aims to increase our knowledge in the methods determining cavitation resistance and xylem anatomical traits. We selected a semi-ring-porous species, Hippophae rhamnoides L., and a diffuse-porous species, Corylus heterophylla F., to clarify the reasons for the difference in cavitation resistance based on detailed xylem anatomical traits and reliable vulnerability curves (VCs). Both Cavitron and bench dehydration (BD) were used to construct VCs. Xylem anatomical traits, including pit membrane ultrastructure of these two species, were determined. The VCs obtained by the two different techniques were of different types for H. rhamnoides, its Cavitron VCs might be unreliable because of open-vessel artifacts. On the basis of BD VCs, H. rhamnoides showed higher cavitation resistance than C. heterophylla, and this is attributed to its low vessel connectivity as well as non-porous and thicker pit membranes.
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Affiliation(s)
- Han Zhao
- College of Forestry, Northwest A&F University, Yangling, 712100, China
| | - Zaimin Jiang
- College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Jin Ma
- College of Forestry, Northwest A&F University, Yangling, 712100, China
| | - Jing Cai
- College of Forestry, Northwest A&F University, Yangling, 712100, China
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11
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Ramirez AR, De Guzman ME, Dawson TE, Ackerly DD. Plant hydraulic traits reveal islands as refugia from worsening drought. CONSERVATION PHYSIOLOGY 2020; 8:coz115. [PMID: 32015878 PMCID: PMC6988607 DOI: 10.1093/conphys/coz115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 12/05/2019] [Accepted: 12/31/2019] [Indexed: 05/14/2023]
Abstract
Relatively mesic environments within arid regions may be important conservation targets as 'climate change refugia' for species persistence in the face of worsening drought conditions. Semi-arid southern California and the relatively mesic environments of California's Channel Islands provide a model system for examining drought responses of plants in potential climate change refugia. Most methods for detecting refugia are focused on 'exposure' of organisms to certain abiotic conditions, which fail to assess how local adaptation or acclimation of plant traits (i.e. 'sensitivity') contribute to or offset the benefits of reduced exposure. Here, we use a comparative plant hydraulics approach to characterize the vulnerability of plants to drought, providing a framework for identifying the locations and trait patterns that underlie functioning climate change refugia. Seasonal water relations, xylem hydraulic traits and remotely sensed vegetation indices of matched island and mainland field sites were used to compare the response of native plants from contrasting island and mainland sites to hotter droughts in the early 21st century. Island plants experienced more favorable water relations and resilience to recent drought. However, island plants displayed low plasticity/adaptation of hydraulic traits to local conditions, which indicates that relatively conserved traits of island plants underlie greater hydraulic safety and localized buffering from regional drought conditions. Our results provide an explanation for how California's Channel Islands function as a regional climate refugia during past and current climate change and demonstrate a physiology-based approach for detecting potential climate change refugia in other systems.
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Affiliation(s)
- Aaron R Ramirez
- Department of Integrative Biology, University of California, 3040 Valley Life Sciences Building #3140 Berkeley CA 94720-3200, USA
- Department of Biology & Environmental Studies, Reed College, Portland, 33203 Southeast Woodstock Blvd., Portland, Oregon 97202-8199, USA
- Corresponding author: Department of Biology & Environmental Studies, Reed College, Portland, 33203 Southeast Woodstock Blvd., Portland, Oregon 97202-8199, USA. Tel: +(503) 517-4101.
| | - Mark E De Guzman
- Department of Biology & Environmental Studies, Reed College, Portland, 33203 Southeast Woodstock Blvd., Portland, Oregon 97202-8199, USA
- Department of Botany & Plant Sciences, University of California, Riverside, 900 University Ave., Riverside CA 92521, USA
| | - Todd E Dawson
- Department of Integrative Biology, University of California, 3040 Valley Life Sciences Building #3140 Berkeley CA 94720-3200, USA
- Department of Environmental Science, Policy, and Management, University of California, 130 Mulford Hall #3114, Berkeley, CA 94720-3114, USA
| | - David D Ackerly
- Department of Integrative Biology, University of California, 3040 Valley Life Sciences Building #3140 Berkeley CA 94720-3200, USA
- Department of Environmental Science, Policy, and Management, University of California, 130 Mulford Hall #3114, Berkeley, CA 94720-3114, USA
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12
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Fontes CG, Cavender-Bares J. Toward an integrated view of the 'elephant': unlocking the mysteries of water transport and xylem vulnerability in oaks. TREE PHYSIOLOGY 2020; 40:1-4. [PMID: 31748794 DOI: 10.1093/treephys/tpz116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/21/2019] [Accepted: 10/24/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Clarissa G Fontes
- Department of Ecology, Evolution and Behavior, University of Minnesota, 1479 Gortner Avenue, Saint Paul, MN 55108, USA
| | - Jeannine Cavender-Bares
- Department of Ecology, Evolution and Behavior, University of Minnesota, 1479 Gortner Avenue, Saint Paul, MN 55108, USA
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13
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Zhang Z, Zhao Y, Zhang X, Tao S, Fang X, Lin X, Chi Y, Zhou L, Wu C. The Accumulated Response of Deciduous Liquidambar formosana Hance and Evergreen Cyclobalanopsis glauca Thunb. Seedlings to Simulated Nitrogen Additions. FRONTIERS IN PLANT SCIENCE 2019; 10:1596. [PMID: 31921245 PMCID: PMC6933011 DOI: 10.3389/fpls.2019.01596] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
Nitrogen depositions in the Yangtze River Delta have is thought to shift the coexistence of mixed evergreen and deciduous species. In this study, the seedlings of the dominant evergreen species Cyclobalanopsis glauca Thunb. and the deciduous species Liquidambar formosana Hance from the Yangtze River Delta were chosen to test their responses to simulated N additions using an ecophysiological approach. N was added to the tree canopy at rates of 0 (CK), 25 kg N ha-1 year-1 (N25), and 50 kg N ha-1 year-1 (N50). The leaf N content per mass (N m, by 44.03 and 49.46%) and total leaf chlorophyll content (Chl, by 72.15 and 63.63%) were enhanced for both species, and C. glauca but not L. formosana tended to allocate more N to Chl per leaf area (with a higher slope). The enhanced N availability and Chl promoted the apparent quantum yield (AQY) significantly by 15.38 and 43.90% for L. formosana and C. glauca, respectively. Hydraulically, the increase in sapwood density (ρ) for L. formosana was almost double that of C. glauca. Synchronous improved sapwood specific hydraulic conductivity (K S, by 37.5%) for C. glauca induced a significant reduction in stomatal conductance (g s) (p < 0.05) in the N50 treatments, which is in contrast to the weak varied g s accompanied by a 59.49% increase in K S for L. formosana. As a result, the elevated maximum photosynthesis (A max) of 12.19% for L. formosana in combination with the increase in the total leaf area (indicated by a 37.82% increase in the leaf area ratio-leaf area divided by total aboveground biomass) ultimately yielded a 34.34% enhancement of total biomass. In contrast, the A max and total biomass were weakly promoted for C. glauca. The reason for these distinct responses may be attributed to the lower water potential at 50% of conductivity lost (P 50) for C. glauca, which enables higher hydraulic safety at the cost of a weak increase in Amax due to the stomatal limitation in response to elevated N availability. Altogether, our results indicate that the deciduous L. formosana would be more susceptible to elevated N availability even if both species received similar N allocation.
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Affiliation(s)
- Zhenzhen Zhang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Yamin Zhao
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Xiaoyan Zhang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Sichen Tao
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Xiong Fang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xingwen Lin
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Yonggang Chi
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Lei Zhou
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
| | - Chaofan Wu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China
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14
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Baker KV, Tai X, Miller ML, Johnson DM. Six co-occurring conifer species in northern Idaho exhibit a continuum of hydraulic strategies during an extreme drought year. AOB PLANTS 2019; 11:plz056. [PMID: 31656556 PMCID: PMC6804486 DOI: 10.1093/aobpla/plz056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
As growing seasons in the northwestern USA lengthen, on track with climate predictions, the mixed conifer forests that dominate this region will experience extended seasonal drought conditions. The year of 2015, which had the most extreme drought for the area on record, offered a potential analogue of future conditions. During this period, we measured the daily courses of water potential and gas exchange as well as the hydraulic conductivity and vulnerability to embolism of six dominant native conifer species, Abies grandis, Larix occidentalis, Pinus ponderosa, Pinus monticola, Pseudotsuga menziesii and Thuja occidentalis, to determine their responses to 5 months of record-low precipitation. The deep ash-capped soils of the region allowed gas exchange to continue without significant evidence of water stress for almost 2 months after the last rainfall event. Midday water potentials never fell below -2.2 MPa in the evergreen species and -2.7 MPa in the one deciduous species. Branch xylem was resistant to embolism, with P 50 values ranging from -3.3 to -7.0 MPa. Root xylem, however, was more vulnerable, with P 50 values from -1.3 to -4.6 MPa. With predawn water potentials as low as -1.3 MPa, the two Pinus species likely experienced declines in root hydraulic conductivity. Stomatal conductance of all six species was significantly responsive to vapour pressure only in the dry months (August-October), with no response evident in the wet months (June-July). While there were similarities among species, they exhibited a continuum of isohydry and safety margins. Despite the severity of this drought, all species were able to continue photosynthesis until mid-October, likely due to the mediating effects of the meter-deep, ash-capped silty-loam soils with large water storage capacity. Areas with these soil types, which are characteristic of much of the northwestern USA, could serve as refugia under drier and warmer future conditions.
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Affiliation(s)
- Kathryn V Baker
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID, USA
- Department of Environmental Science, Marist College, Poughkeepsie, NY, USA
| | - Xiaonan Tai
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA
| | - Megan L Miller
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID, USA
| | - Daniel M Johnson
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
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15
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Huber AE, Melcher PJ, Piñeros MA, Setter TL, Bauerle TL. Signal coordination before, during and after stomatal closure in response to drought stress. THE NEW PHYTOLOGIST 2019; 224:675-688. [PMID: 31364171 DOI: 10.1111/nph.16082] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/22/2019] [Indexed: 05/27/2023]
Abstract
Signal coordination in response to changes in water availability remains unclear, as does the role of embolism events in signaling drought stress. Sunflowers were exposed to two drought treatments of varying intensity while simultaneously monitoring changes in stomatal conductance, acoustic emissions (AE), turgor pressure, surface-level electrical potential, organ-level water potential and leaf abscisic acid (ABA) concentration. Leaf, stem and root xylem vulnerability to embolism were measured with the single vessel injection technique. In both drought treatments, it was found that AE events and turgor changes preceded the onset of stomatal closure, whereas electrical surface potentials shifted concurrently with stomatal closure. Leaf-level ABA concentration did not change until after stomata were closed. Roots and petioles were equally vulnerable to drought stress based on the single vessel injection technique. However, anatomical analysis of the xylem indicated that the increased AE events were not a result of xylem embolism formation. Additionally, roots and stems never reached a xylem pressure threshold that would initiate runaway embolism throughout the entire experiment. It is concluded that stomatal closure was not embolism-driven, but, rather, that onset of stomatal closure was most closely correlated with the hydraulic signal from changes in leaf turgor.
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Affiliation(s)
- Annika E Huber
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, NY, USA
| | - Peter J Melcher
- Biology Department, Center for Natural Sciences, Ithaca College, Ithaca, NY, 14850, NY, USA
| | - Miguel A Piñeros
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, NY, USA
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, 14853, NY, USA
| | - Tim L Setter
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, NY, USA
| | - Taryn L Bauerle
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, NY, USA
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16
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Kiorapostolou N, Da Sois L, Petruzzellis F, Savi T, Trifilò P, Nardini A, Petit G. Vulnerability to xylem embolism correlates to wood parenchyma fraction in angiosperms but not in gymnosperms. TREE PHYSIOLOGY 2019; 39:1675-1684. [PMID: 31211372 DOI: 10.1093/treephys/tpz068] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 03/26/2019] [Accepted: 05/17/2019] [Indexed: 05/26/2023]
Abstract
Understanding which structural and functional traits are linked to species' vulnerability to embolism formation (P50) may provide fundamental knowledge on plant strategies to maintain an efficient water transport. We measured P50, wood density (WD), mean conduit area, conduit density, percentage areas occupied by vessels, parenchyma cells (PATOT) and fibers (FA) on branches of angiosperm and gymnosperm species. Moreover, we compiled a dataset of published hydraulic and anatomical data to be compared with our results. Species more vulnerable to embolism had lower WD. In angiosperms, the variability in WD was better explained by PATOT and FA, which were highly correlated. Angiosperms with a higher P50 (less negative) had a higher amount of PATOT and total amount of nonstructural carbohydrates. Instead, in gymnosperms, P50 vs PATOT was not significant. The correlation between PATOT and P50 might have a biological meaning and also suggests that the causality of the commonly observed relationship of WD vs P50 is indirect and dependent on the parenchyma fraction. Our study suggests that angiosperms have a potential active embolism reversal capacity in which parenchyma has an important role, while in gymnosperms this might not be the case.
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Affiliation(s)
- Natasa Kiorapostolou
- Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova, Viale dell'Università 16, Legnaro, PD 35020, Italy
| | - Luca Da Sois
- Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova, Viale dell'Università 16, Legnaro, PD 35020, Italy
| | - Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Tadeja Savi
- Institute for Viticulture and Pomology, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Konrad Lorenz Straße 24, Tulln, Vienna, 3430, Austria
| | - Patrizia Trifilò
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, Messina 98166, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Giai Petit
- Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova, Viale dell'Università 16, Legnaro, PD 35020, Italy
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17
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Peng G, Yang D, Liang Z, Li J, Tyree MT. An improved centrifuge method for determining water extraction curves and vulnerability curves in the long-vessel species Robinia pseudoacacia. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4865-4876. [PMID: 31056686 PMCID: PMC6760279 DOI: 10.1093/jxb/erz206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 04/26/2019] [Indexed: 05/29/2023]
Abstract
Significant improvements to the centrifuge water-extraction method of measuring the percentage loss volume of water (PLV) and corresponding vulnerability curves (VCs) are reported. Cochard and Sperry rotors are both incapable of measuring the VCs of species with long vessels because of premature embolism induced by hypothetical nanoparticles that can be drawn into segments during flow measurement. In contrast, water extraction pushes nanoparticles out of the sample. This study focuses on a long-vessel species, Robinia pseudoacacia, for which many VCs have been constructed by different methods, and the daily water relations have been quantified. PLV extraction curves have dual Weibull curves, and this paper focuses on the second Weibull curve because it involves the extraction of water from vessels, as proven by staining methods. We demonstrate an improved water extraction method after evaporation correction that has accuracy to within 0.5%, shows good agreement with two traditional methods that are slower and less accurate, and is immune to nanoparticle artefacts. Using Poiseuille's Law and the geometry of vessels, we argue that the percentage loss of conductivity (PLC) equals 2PLV-PLV2 in a special case where all vessels, regardless of size, have the same vulnerability curve. In this special case, this equation predicts the data reasonably well.
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Affiliation(s)
- Guoquan Peng
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Dongmei Yang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
| | - Zhao Liang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
| | - Junhui Li
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
| | - Melvin T Tyree
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
- Center for Nano- and Micro-Mechanics, Engineering Mechanics, Tsinghua University, Beijing, China
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18
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Hammond WM, Yu K, Wilson LA, Will RE, Anderegg WRL, Adams HD. Dead or dying? Quantifying the point of no return from hydraulic failure in drought-induced tree mortality. THE NEW PHYTOLOGIST 2019; 223:1834-1843. [PMID: 31087656 PMCID: PMC6771894 DOI: 10.1111/nph.15922] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 05/05/2019] [Indexed: 05/18/2023]
Abstract
Determining physiological mechanisms and thresholds for climate-driven tree die-off could help improve global predictions of future terrestrial carbon sinks. We directly tested for the lethal threshold in hydraulic failure - an inability to move water due to drought-induced xylem embolism - in a pine sapling experiment. In a glasshouse experiment, we exposed loblolly pine (Pinus taeda) saplings (n = 83) to drought-induced water stress ranging from mild to lethal. Before rewatering to relieve drought stress, we measured native hydraulic conductivity and foliar color change. We monitored all measured individuals for survival or mortality. We found a lethal threshold at 80% loss of hydraulic conductivity - a point of hydraulic failure beyond which it is more likely trees will die, than survive, and describe mortality risk across all levels of water stress. Foliar color changes lagged behind hydraulic failure - best predicting when trees had been dead for some time, rather than when they were dying. Our direct measurement of native conductivity, while monitoring the same individuals for survival or mortality, quantifies a continuous probability of mortality risk from hydraulic failure. Predicting tree die-off events and understanding the mechanism involved requires knowledge not only of when trees are dead, but when they begin dying - having passed the point of no return.
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Affiliation(s)
- William M. Hammond
- Plant Biology, Ecology and EvolutionOklahoma State UniversityStillwaterOK74078USA
| | - Kailiang Yu
- School of Biological SciencesUniversity of UtahSalt Lake CityUT84112USA
| | - Luke A. Wilson
- Plant Biology, Ecology and EvolutionOklahoma State UniversityStillwaterOK74078USA
- Department of Natural Resource Ecology and ManagementOklahoma State UniversityStillwaterOK74078USA
| | - Rodney E. Will
- Department of Natural Resource Ecology and ManagementOklahoma State UniversityStillwaterOK74078USA
| | | | - Henry D. Adams
- Plant Biology, Ecology and EvolutionOklahoma State UniversityStillwaterOK74078USA
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19
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Venturas MD, Pratt RB, Jacobsen AL, Castro V, Fickle JC, Hacke UG. Direct comparison of four methods to construct xylem vulnerability curves: Differences among techniques are linked to vessel network characteristics. PLANT, CELL & ENVIRONMENT 2019; 42:2422-2436. [PMID: 30997689 DOI: 10.1111/pce.13565] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/12/2019] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
During periods of dehydration, water transport through xylem conduits can become blocked by embolism formation. Xylem embolism compromises water supply to leaves and may lead to losses in productivity or plant death. Vulnerability curves (VCs) characterize plant losses in conductivity as xylem pressures decrease. VCs are widely used to characterize and predict plant water use at different levels of water availability. Several methodologies for constructing VCs exist and sometimes produce different results for the same plant material. We directly compared four VC construction methods on stems of black cottonwood (Populus trichocarpa), a model tree species: dehydration, centrifuge, X-ray-computed microtomography (microCT), and optical. MicroCT VC was the most resistant, dehydration and centrifuge VCs were intermediate, and optical VC was the most vulnerable. Differences among VCs were not associated with how cavitation was induced but were related to how losses in conductivity were evaluated: measured hydraulically (dehydration and centrifuge) versus evaluated from visual information (microCT and optical). Understanding how and why methods differ in estimating vulnerability to xylem embolism is important for advancing knowledge in plant ecophysiology, interpreting literature data, and using accurate VCs in water flux models for predicting plant responses to drought.
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Affiliation(s)
- Martin D Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, 84112, Utah, USA
| | - R Brandon Pratt
- Department of Biology, California State University Bakersfield, Bakersfield, 93311, California, USA
| | - Anna L Jacobsen
- Department of Biology, California State University Bakersfield, Bakersfield, 93311, California, USA
| | - Viridiana Castro
- Department of Biology, California State University Bakersfield, Bakersfield, 93311, California, USA
| | - Jaycie C Fickle
- Department of Biology, California State University Bakersfield, Bakersfield, 93311, California, USA
| | - Uwe G Hacke
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
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20
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Rodriguez-Zaccaro FD, Valdovinos-Ayala J, Percolla MI, Venturas MD, Pratt RB, Jacobsen AL. Wood structure and function change with maturity: Age of the vascular cambium is associated with xylem changes in current-year growth. PLANT, CELL & ENVIRONMENT 2019; 42:1816-1831. [PMID: 30707440 DOI: 10.1111/pce.13528] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/27/2019] [Accepted: 01/28/2019] [Indexed: 06/09/2023]
Abstract
Xylem vessel structure changes as trees grow and mature. Age- and development-related changes in xylem structure are likely related to changes in hydraulic function. We examined whether hydraulic function, including hydraulic conductivity and vulnerability to water-stress-induced xylem embolism, changed over the course of cambial development in the stems of 17 tree species. We compared current-year growth of young (1-4 years), intermediate (2-7 years), and older (3-10 years) stems occurring in series along branches. Diffuse and ring porous species were examined, but nearly all species produced only diffuse porous xylem in the distal branches that were examined irrespective of their mature xylem porosity type. Vessel diameter and length increased with cambial age. Xylem became both more conductive and more cavitation resistant with cambial age. Ring porous species had longer and wider vessels and xylem that had higher conductivity and was more vulnerable to cavitation; however, these differences between porosity types were not present in young stem samples. Understanding plant hydraulic function and architecture requires the sampling of multiple-aged tissues because plants may vary considerably in their xylem structural and functional traits throughout the plant body, even over relatively short distances and closely aged tissues.
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Affiliation(s)
| | | | - Marta I Percolla
- Department of Biology, California State University, Bakersfield, Bakersfield, California
| | - Martin D Venturas
- Department of Biology, California State University, Bakersfield, Bakersfield, California
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Madrid, Spain
| | - R Brandon Pratt
- Department of Biology, California State University, Bakersfield, Bakersfield, California
| | - Anna L Jacobsen
- Department of Biology, California State University, Bakersfield, Bakersfield, California
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21
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Yin P, Meng F, Liu Q, An R, Cai J, Du G. A comparison of two centrifuge techniques for constructing vulnerability curves: insight into the 'open-vessel' artifact. PHYSIOLOGIA PLANTARUM 2019; 165:701-710. [PMID: 29602179 DOI: 10.1111/ppl.12738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 03/16/2018] [Accepted: 03/25/2018] [Indexed: 06/08/2023]
Abstract
A vulnerability curve (VC) describes the extent of xylem cavitation resistance. Centrifuges have been used to generate VCs for decades via static- and flow-centrifuge methods. Recently, the validity of the centrifuge techniques has been questioned. Researchers have hypothesized that the centrifuge techniques might yield unreliable VCs due to the open-vessel artifact. However, other researchers reject this hypothesis. The focus of the dispute is centered on whether exponential VCs are more reliable when the static-centrifuge method is used rather than the flow-centrifuge method. To further test the reliability of the centrifuge technique, two centrifuges were manufactured to simulate the static- and flow-centrifuge methods. VCs of three species with open vessels of known lengths were constructed using the two centrifuges. The results showed that both centrifuge techniques produced invalid VCs for Robinia because the water flow through stems under mild tension in centrifuges led to an increasing loss of water conductivity. In addition, the injection of water in the flow-centrifuge exacerbated the loss of water conductivity. However, both centrifuge techniques yielded reliable VCs for Prunus, regardless of the presence of open vessels in the tested samples. We conclude that centrifuge techniques can be used in species with open vessels only when the centrifuge produces a VC that matches the bench-dehydration VC.
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Affiliation(s)
- Pengxian Yin
- College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Feng Meng
- College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Qing Liu
- College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Rui An
- College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Jing Cai
- College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Guangyuan Du
- College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China
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22
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López R, Nolf M, Duursma RA, Badel E, Flavel RJ, Cochard H, Choat B. Mitigating the open vessel artefact in centrifuge-based measurement of embolism resistance. TREE PHYSIOLOGY 2019; 39:143-155. [PMID: 30085232 DOI: 10.1093/treephys/tpy083] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/03/2018] [Indexed: 06/08/2023]
Abstract
Centrifuge-based techniques to assess xylem vulnerability to embolism are increasingly being used, although we are yet to reach a consensus on the nature and extent of artefactual embolism observed in some angiosperm species. In particular, there is disagreement over whether these artefacts influence both the spin (Cavitron) and static versions of the centrifuge technique equally. We tested two methods for inducing embolism: bench dehydration and centrifugation. We used three methods to measure the resulting loss of conductivity: gravimetric flow measured in bench-dehydrated and centrifuged samples (static centrifuge), in situ flow measured under tension during spinning in the centrifuge (Cavitron) and direct imaging using X-ray computed microtomography (microCT) observations in stems of two species of Hakea that differ in vessel length. Both centrifuge techniques were prone to artefactual embolism in samples with maximum vessel length longer than, or similar to, the centrifuge rotor diameter. Observations with microCT indicated that this artefactual embolism occurred in the outermost portions of samples. The artefact was largely eliminated if flow was measured in an excised central part of the segment in the static centrifuge or starting measurements with the Cavitron at pressures lower than the threshold of embolism formation in open vessels. The simulations of loss of conductivity in centrifuged samples with a new model, CAVITOPEN, confirmed that the impact of open vessels on the vulnerability to embolism curve was higher when vessels were long, samples short and when embolism is formed in open vessels at less negative pressures. This model also offers a robust and quantitative tool to test and correct for artefactual embolism at low xylem tensions.
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Affiliation(s)
- Rosana López
- Université Clermont Auvergne, INRA, PIAF, 5, chemin de Beaulieu, Clermont-Ferrand, France
- Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, C/ José Antonio Novais 10, Madrid, Spain
| | - Markus Nolf
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, Australia
| | - Remko A Duursma
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, Australia
| | - Eric Badel
- Université Clermont Auvergne, INRA, PIAF, 5, chemin de Beaulieu, Clermont-Ferrand, France
| | - Richard J Flavel
- School of Environmental and Rural Science, University of New England, Elm Avenue, 2351 Armidale, NSW, Australia
| | - Hervé Cochard
- Université Clermont Auvergne, INRA, PIAF, 5, chemin de Beaulieu, Clermont-Ferrand, France
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, Australia
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23
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Hao X, Tang H, Wang B, Yue C, Wang L, Zeng J, Yang Y, Wang X. Integrative transcriptional and metabolic analyses provide insights into cold spell response mechanisms in young shoots of the tea plant. TREE PHYSIOLOGY 2018; 38:1041-1052. [PMID: 29401304 DOI: 10.1093/treephys/tpy001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 01/15/2018] [Indexed: 05/03/2023]
Abstract
Green tea has attracted an increasing number of consumers worldwide due to its multiple health benefits. With the increase in global warming, more frequent cold spells in the spring often cause more serious damage to green tea production because of the young leaves used. We recorded the changes in climatic conditions during a typical cold spell and the damage symptoms caused by the cold spell in different tea cultivars and breeding lines. By simulating the low temperature of a cold spell under controlled conditions, comparative transcriptome and metabolic analyses were performed with sprouting shoots. Many pathways and genes were regulated differentially by the cold spell conditions. Taking into account the metabolic analysis, the results suggested that the mitogen-activated protein kinase (MAPK)-dependent ethylene and calcium signalling pathways were two major early cold-responsive mechanisms involved in sprouting shoots and were followed by the induction of the Inducer of CBF Expressions (ICE)-C-repeat binding factors (CBF)-cold-responsive (COR) signalling pathway to augment cold tolerance. During the cold shock, growth, photosynthesis and secondary metabolism-mainly involving flavonoid biosynthesis-were remarkably affected. Notably, the increased starch metabolism, which might be dependent on the high expression of β-amylase3 (BAM3) induced by CBF, played crucial roles in protecting young shoots against freezing cold. A schematic diagram of cold spell response mechanisms specifically involved in the sprouting shoots of the tea plant is ultimately proposed. Some essential transcriptional and metabolic changes were further confirmed in the plant materials under natural cold spell conditions. Our results provide a global view of the reprograming of transcription and metabolism in sprouting tea shoots during a cold spell and meaningful information for future practices.
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Affiliation(s)
- Xinyuan Hao
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, China
| | - Hu Tang
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, China
| | - Bo Wang
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Chuan Yue
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, China
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China
| | - Lu Wang
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, China
| | - Jianming Zeng
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, China
| | - Yajun Yang
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, China
| | - Xinchao Wang
- National Center for Tea Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, China
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Klein T, Zeppel MJB, Anderegg WRL, Bloemen J, De Kauwe MG, Hudson P, Ruehr NK, Powell TL, von Arx G, Nardini A. Xylem embolism refilling and resilience against drought-induced mortality in woody plants: processes and trade-offs. Ecol Res 2018. [DOI: 10.1007/s11284-018-1588-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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De Guzman ME, Santiago LS, Schnitzer SA, Álvarez-Cansino L. Trade-offs between water transport capacity and drought resistance in neotropical canopy liana and tree species. TREE PHYSIOLOGY 2017; 37:1404-1414. [PMID: 27672189 DOI: 10.1093/treephys/tpw086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 08/04/2016] [Indexed: 06/06/2023]
Abstract
In tropical forest canopies, it is critical for upper shoots to efficiently provide water to leaves for physiological function while safely preventing loss of hydraulic conductivity due to cavitation during periods of soil water deficit or high evaporative demand. We compared hydraulic physiology of upper canopy trees and lianas in a seasonally dry tropical forest to test whether trade-offs between safety and efficiency of water transport shape differences in hydraulic function between these two major tropical woody growth forms. We found that lianas showed greater maximum stem-specific hydraulic conductivity than trees, but lost hydraulic conductivity at less negative water potentials than trees, resulting in a negative correlation and trade-off between safety and efficiency of water transport. Lianas also exhibited greater diurnal changes in leaf water potential than trees. The magnitude of diurnal water potential change was negatively correlated with sapwood capacitance, indicating that lianas are highly reliant on conducting capability to maintain leaf water status, whereas trees relied more on stored water in stems to maintain leaf water status. Leaf nitrogen concentration was related to maximum leaf-specific hydraulic conductivity only for lianas suggesting that greater water transport capacity is more tied to leaf processes in lianas compared to trees. Our results are consistent with a trade-off between safety and efficiency of water transport and may have implications for increasing liana abundance in neotropical forests.
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Affiliation(s)
- Mark E De Guzman
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Louis S Santiago
- Department of Botany & Plant Sciences, University of California, Riverside, CA 92521, USA
- Smithsonian Tropical Research Institute, Apartado 0843-0392, Balboa, Panamá
| | - Stefan A Schnitzer
- Smithsonian Tropical Research Institute, Apartado 0843-0392, Balboa, Panamá
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA
| | - Leonor Álvarez-Cansino
- Smithsonian Tropical Research Institute, Apartado 0843-0392, Balboa, Panamá
- Department of Plant Ecology, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
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26
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Torres-Ruiz JM, Cochard H, Choat B, Jansen S, López R, Tomášková I, Padilla-Díaz CM, Badel E, Burlett R, King A, Lenoir N, Martin-StPaul NK, Delzon S. Xylem resistance to embolism: presenting a simple diagnostic test for the open vessel artefact. THE NEW PHYTOLOGIST 2017; 215:489-499. [PMID: 28467616 DOI: 10.1111/nph.14589] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/28/2017] [Indexed: 05/21/2023]
Abstract
Xylem vulnerability to embolism represents an essential trait for the evaluation of the impact of hydraulics in plant function and ecology. The standard centrifuge technique is widely used for the construction of vulnerability curves, although its accuracy when applied to species with long vessels remains under debate. We developed a simple diagnostic test to determine whether the open-vessel artefact influences centrifuge estimates of embolism resistance. Xylem samples from three species with differing vessel lengths were exposed to less negative xylem pressures via centrifugation than the minimum pressure the sample had previously experienced. Additional calibration was obtained from non-invasive measurement of embolism on intact olive plants by X-ray microtomography. Results showed artefactual decreases in hydraulic conductance (k) for samples with open vessels when exposed to a less negative xylem pressure than the minimum pressure they had previously experienced. X-Ray microtomography indicated that most of the embolism formation in olive occurs at xylem pressures below -4.0 MPa, reaching 50% loss of hydraulic conductivity at -5.3 MPa. The artefactual reductions in k induced by centrifugation underestimate embolism resistance data of species with long vessels. A simple test is suggested to avoid this open vessel artefact and to ensure the reliability of this technique in future studies.
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Affiliation(s)
| | - Hervé Cochard
- PIAF, INRA, University of Clermont-Auvergne, 63100, Clermont-Ferrand, France
| | - Brendan Choat
- Western Sydney University, Hawkesbury Institute for the Environment, Richmond, NSW, 2753, Australia
| | - Steven Jansen
- Ulm University, Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Rosana López
- PIAF, INRA, University of Clermont-Auvergne, 63100, Clermont-Ferrand, France
- Western Sydney University, Hawkesbury Institute for the Environment, Richmond, NSW, 2753, Australia
| | - Ivana Tomášková
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, 165 00, Praha 6 - Suchdol, Czech Republic
| | - Carmen M Padilla-Díaz
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, 10, 41012, Sevilla, Spain
| | - Eric Badel
- PIAF, INRA, University of Clermont-Auvergne, 63100, Clermont-Ferrand, France
| | - Regis Burlett
- BIOGECO, INRA, University of Bordeaux, 33615, Pessac, France
| | - Andrew King
- Synchrotron SOLEIL, L'Orme de Merisiers, 91190 Saint-Aubin - BP48, Gif-sur-Yvette Cedex, France
| | - Nicolas Lenoir
- CNRS, University of Bordeaux, UMS 3626 Placamat, F-33608, Pessac, France
| | | | - Sylvain Delzon
- BIOGECO, INRA, University of Bordeaux, 33615, Pessac, France
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Venturas MD, Sperry JS, Hacke UG. Plant xylem hydraulics: What we understand, current research, and future challenges. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:356-389. [PMID: 28296168 DOI: 10.1111/jipb.12534] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/09/2017] [Indexed: 05/22/2023]
Abstract
Herein we review the current state-of-the-art of plant hydraulics in the context of plant physiology, ecology, and evolution, focusing on current and future research opportunities. We explain the physics of water transport in plants and the limits of this transport system, highlighting the relationships between xylem structure and function. We describe the great variety of techniques existing for evaluating xylem resistance to cavitation. We address several methodological issues and their connection with current debates on conduit refilling and exponentially shaped vulnerability curves. We analyze the trade-offs existing between water transport safety and efficiency. We also stress how little information is available on molecular biology of cavitation and the potential role of aquaporins in conduit refilling. Finally, we draw attention to how plant hydraulic traits can be used for modeling stomatal responses to environmental variables and climate change, including drought mortality.
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Affiliation(s)
- Martin D Venturas
- Department of Biology, University of Utah, 257 S 1400E, Salt Lake City, UT, 84112, USA
| | - John S Sperry
- Department of Biology, University of Utah, 257 S 1400E, Salt Lake City, UT, 84112, USA
| | - Uwe G Hacke
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
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28
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Gleason SM, Wiggans DR, Bliss CA, Young JS, Cooper M, Willi KR, Comas LH. Embolized Stems Recover Overnight in Zea mays: The Role of Soil Water, Root Pressure, and Nighttime Transpiration. FRONTIERS IN PLANT SCIENCE 2017; 8:662. [PMID: 28503183 PMCID: PMC5408072 DOI: 10.3389/fpls.2017.00662] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/11/2017] [Indexed: 05/26/2023]
Abstract
It is not currently well-understood how much xylem conductance is lost in maize plants during the day, if conductance is recovered during the night, or what soil water conditions are required for recovery to take place. To answer these questions we designed a greenhouse experiment whereby two genetically dissimilar maize genotypes were subjected to a level of water stress commonly experienced in the field (Ψxylem ∼-2 MPa). We then measured the loss of stem-specific conductivity associated with this level of stress, as well as the overnight recovery following three re-watering treatments: Ψsoil ∼ 0 MPa, Ψsoil ∼-0.40 MPa, and Ψsoil ∼-1.70 MPa. Mid-day leaf water potentials of -1.98 MPa resulted in stem-specific conductivity (KS) values that were 31.5% of maximal (i.e., 68% loss). Returning soils to field capacity (Ψsoil ∼ 0 MPa) overnight allowed for the significant recovery of KS (76% of maximal), whereas partial watering (Ψsoil ∼-0.40 MPa) resulted KS values that were 51.7% of maximal values, whereas not watering resulted in no recovery (35.4% of maximal; Ψsoil ∼-1.7 MPa). Recovery of KS was facilitated by the generation of root pressure and low rates of nighttime transpiration.
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Affiliation(s)
- Sean M. Gleason
- Water Management and Systems Research Unit, United States Department of Agriculture – Agricultural Research Service, Fort CollinsCO, USA
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29
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Nardini A, Savi T, Trifilò P, Lo Gullo MA. Drought Stress and the Recovery from Xylem Embolism in Woody Plants. PROGRESS IN BOTANY VOL. 79 2017. [DOI: 10.1007/124_2017_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Torres-Ruiz JM, Cochard H, Mencuccini M, Delzon S, Badel E. Direct observation and modelling of embolism spread between xylem conduits: a case study in Scots pine. PLANT, CELL & ENVIRONMENT 2016; 39:2774-2785. [PMID: 27739597 DOI: 10.1111/pce.12840] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 09/29/2016] [Accepted: 10/04/2016] [Indexed: 06/06/2023]
Abstract
Xylem embolism is one of the main processes involved in drought-related plant mortality. Although its consequences for plant physiology are already well described, embolism formation and spread are poorly evaluated and modelled, especially for tracheid-based species. The aim of this study was to assess the embolism formation and spread in Pinus sylvestris as a case study using X-ray microtomography and hydraulics methods. We also evaluated the potential effects of cavitation fatigue on vulnerability to embolism and the micro-morphology of the bordered pits using scanning electron microscopy (SEM) to test for possible links between xylem anatomy and embolism spread. Finally, a novel model was developed to simulate the spread of embolism in a 2D anisotropic cellular structure. Results showed a large variability in the formation and spread of embolism within a ring despite no differences being observed in intertracheid pit membrane anatomical traits. Simulations from the model showed a highly anisotropic tracheid-to-tracheid embolism spreading pattern, which confirms the major role of tracheid-to-tracheid air seeding to explain how embolism spreads in Scots pine. The results also showed that prior embolism removal from the samples reduced the resistance to embolism of the xylem and could result in overestimates of vulnerability to embolism.
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Affiliation(s)
| | - Hervé Cochard
- PIAF, INRA, Univ. Clermont Auvergne, 63000, Clermont-Ferrand, France
| | - Maurizio Mencuccini
- School of Geosciences, University of Edinburgh, Crew Building, The Kings Buildings, West Main Road, EH93JF, Edinburgh, UK
- ICREA at CREAF, 08193, Cerdanyola del Vallès, Barcelona, Spain
| | | | - Eric Badel
- PIAF, INRA, Univ. Clermont Auvergne, 63000, Clermont-Ferrand, France
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31
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Barotto AJ, Fernandez ME, Gyenge J, Meyra A, Martinez-Meier A, Monteoliva S. First insights into the functional role of vasicentric tracheids and parenchyma in eucalyptus species with solitary vessels: do they contribute to xylem efficiency or safety? TREE PHYSIOLOGY 2016; 36:1485-1497. [PMID: 27614358 DOI: 10.1093/treephys/tpw072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/18/2016] [Accepted: 07/05/2016] [Indexed: 06/06/2023]
Abstract
The relationship between hydraulic specific conductivity (ks) and vulnerability to cavitation (VC) with size and number of vessels has been studied in many angiosperms. However, few of the studies link other cell types (vasicentric tracheids (VT), fibre-tracheids, parenchyma) with these hydraulic functions. Eucalyptus is one of the most important genera in forestry worldwide. It exhibits a complex wood anatomy, with solitary vessels surrounded by VT and parenchyma, which could serve as a good model to investigate the functional role of the different cell types in xylem functioning. Wood anatomy (several traits of vessels, VT, fibres and parenchyma) in conjunction with maximum ks and VC was studied in adult trees of commercial species with medium-to-high wood density (Eucalyptus globulus Labill., Eucalyptus viminalis Labill. and Eucalyptus camaldulensis Dehnh.). Traits of cells accompanying vessels presented correlations with functional variables suggesting that they contribute to both increasing connectivity between adjacent vessels-and, therefore, to xylem conduction efficiency-and decreasing the probability of embolism propagation into the tissue, i.e., xylem safety. All three species presented moderate-to-high resistance to cavitation (mean P50 values = -2.4 to -4.2 MPa) with no general trade-off between efficiency and safety at the interspecific level. The results in these species do not support some well-established hypotheses of the functional meaning of wood anatomy.
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Affiliation(s)
- Antonio José Barotto
- Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, Diagonal 113 469, (1900) La Plata, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, (C1033AAJ) CABA, Argentina
| | - María Elena Fernandez
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, (C1033AAJ) CABA, Argentina
- INTA, EEA Balcarce-Oficina Tandil, Gral. Martín Rodríguez 370, (7000) Tandil, Argentina
| | - Javier Gyenge
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, (C1033AAJ) CABA, Argentina
- INTA, EEA Balcarce-Oficina Tandil, Gral. Martín Rodríguez 370, (7000) Tandil, Argentina
| | - Ariel Meyra
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, (C1033AAJ) CABA, Argentina
- Instituto de Física de Líquidos y Sistemas Biológicos (IFLYSIB-UNLP-CONICET), Calle 59 789, (1900) La Plata, Argentina
| | | | - Silvia Monteoliva
- Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, Diagonal 113 469, (1900) La Plata, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, (C1033AAJ) CABA, Argentina
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Bartlett MK, Klein T, Jansen S, Choat B, Sack L. The correlations and sequence of plant stomatal, hydraulic, and wilting responses to drought. Proc Natl Acad Sci U S A 2016; 113:13098-13103. [PMID: 27807136 PMCID: PMC5135344 DOI: 10.1073/pnas.1604088113] [Citation(s) in RCA: 246] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Climate change is expected to exacerbate drought for many plants, making drought tolerance a key driver of species and ecosystem responses. Plant drought tolerance is determined by multiple traits, but the relationships among traits, either within individual plants or across species, have not been evaluated for general patterns across plant diversity. We synthesized the published data for stomatal closure, wilting, declines in hydraulic conductivity in the leaves, stems, and roots, and plant mortality for 262 woody angiosperm and 48 gymnosperm species. We evaluated the correlations among the drought tolerance traits across species, and the general sequence of water potential thresholds for these traits within individual plants. The trait correlations across species provide a framework for predicting plant responses to a wide range of water stress from one or two sampled traits, increasing the ability to rapidly characterize drought tolerance across diverse species. Analyzing these correlations also identified correlations among the leaf and stem hydraulic traits and the wilting point, or turgor loss point, beyond those expected from shared ancestry or independent associations with water stress alone. Further, on average, the angiosperm species generally exhibited a sequence of drought tolerance traits that is expected to limit severe tissue damage during drought, such as wilting and substantial stem embolism. This synthesis of the relationships among the drought tolerance traits provides crucial, empirically supported insight into representing variation in multiple traits in models of plant and ecosystem responses to drought.
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Affiliation(s)
- Megan K Bartlett
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095;
| | - Tamir Klein
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Steven Jansen
- Ulm University, Institute of Systematic Botany and Ecology, 89081 Ulm, Germany
| | - Brendan Choat
- Western Sydney University, Hawkesbury Institute for the Environment, Richmond, NSW 2753, Australia
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095
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Jacobsen AL, Tobin MF, Toschi HS, Percolla MI, Pratt RB. Structural determinants of increased susceptibility to dehydration-induced cavitation in post-fire resprouting chaparral shrubs. PLANT, CELL & ENVIRONMENT 2016; 39:2473-2485. [PMID: 27423060 DOI: 10.1111/pce.12802] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/06/2016] [Accepted: 07/11/2016] [Indexed: 06/06/2023]
Abstract
It is well established that transpiration and photosynthetic rates generally increase in resprouting shoots after fire in chaparral shrublands. By contrast, little is known about how plant hydraulic function varies during this same recovery period. We hypothesized that vascular traits, both functional and structural, would also shift in order to support this heightened level of gas exchange and growth. We examined stem xylem-specific hydraulic conductivity (Ks ) and resistance to cavitation (P50 ) for eight chaparral shrub species as well as several potential xylem structural determinants of hydraulic function and compared established unburned plants and co-occurring post-fire resprouting plants. Unburned plants were generally more resistant to cavitation than resprouting plants, but the two groups did not differ in Ks . Resprouting plants had altered vessel structure compared with unburned plants, with resprouting plants having both wider diameter vessels and higher inter-vessel pit density. For biomechanics, unburned plants had both stronger and denser stem xylem tissue than resprouting plants. Shifts in hydraulic structure and function resulted in resprouting plants being more vulnerable to dehydration. The interaction between time since disturbance (i.e. resprouting versus established stands) and drought may complicate attempts to predict mortality risk of resprouting plants.
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Affiliation(s)
- Anna L Jacobsen
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Highway, Bakersfield, CA, 93311, USA.
| | - Michael F Tobin
- Department of Natural Sciences, University of Houston-Downtown, One Main Street, Houston, TX, 77002, USA
| | - Hayden S Toschi
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Highway, Bakersfield, CA, 93311, USA
| | - Marta I Percolla
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Highway, Bakersfield, CA, 93311, USA
| | - R Brandon Pratt
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Highway, Bakersfield, CA, 93311, USA
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Umebayashi T, Morita T, Utsumi Y, Kusumoto D, Yasuda Y, Haishi T, Fukuda K. Spatial distribution of xylem embolisms in the stems of Pinus thunbergii at the threshold of fatal drought stress. TREE PHYSIOLOGY 2016; 36:1210-1218. [PMID: 27354714 DOI: 10.1093/treephys/tpw050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 05/16/2016] [Indexed: 05/26/2023]
Abstract
Although previous studies have suggested that branch dieback and whole-plant death due to drought stress occur at 50-88% loss of stem hydraulic conductivity (P50 and P88, respectively), the dynamics of catastrophic failure in the water-conducting pathways in whole plants subjected to drought remain poorly understood. We examined the dynamics of drought stress tolerance in 3-year-old Japanese black pine (Pinus thunbergii Parl.). We nondestructively monitored (i) the spatial distribution of drought-induced embolisms in the stem at greater than P50 and (ii) recovery from embolisms following rehydration. Stem water distributions were visualized by cryo-scanning electron microscopy. The percentages of both embolized area and loss of hydraulic conductivity showed similar patterns of increase, although the water loss in xylem increased markedly at -5.0 MPa or less. One seedling that had reached 72% loss of the water-conducting area survived and the xylem water potential recovered to -0.3 MPa. We concluded that Japanese black pines may need to maintain water-filled tracheids within earlywood of the current-year xylem under natural conditions to avoid disconnection of water movement between the stem and the tops of branches. It is necessary to determine the spatial distribution of embolisms around the point of the lethal threshold to gain an improved understanding of plant survival under conditions of drought.
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Affiliation(s)
- Toshihiro Umebayashi
- Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8563, Japan
- Present address: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Toshimitsu Morita
- Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8563, Japan
| | - Yasuhiro Utsumi
- Ashoro Research Forest, Kyushu University, Ashoro 089-3705, Japan
| | - Dai Kusumoto
- The University of Tokyo Tanashi Forest, The University of Tokyo, Nishitokyo 188-0002, Japan
| | - Yuko Yasuda
- Ashoro Research Forest, Kyushu University, Ashoro 089-3705, Japan
| | | | - Kenji Fukuda
- Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8563, Japan
- Present address: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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Venturas MD, Rodriguez-Zaccaro FD, Percolla MI, Crous CJ, Jacobsen AL, Pratt RB. Single vessel air injection estimates of xylem resistance to cavitation are affected by vessel network characteristics and sample length. TREE PHYSIOLOGY 2016; 36:1247-1259. [PMID: 27358206 DOI: 10.1093/treephys/tpw055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/30/2016] [Indexed: 06/06/2023]
Abstract
Xylem resistance to cavitation is an important trait that is related to the ecology and survival of plant species. Vessel network characteristics, such as vessel length and connectivity, could affect the spread of emboli from gas-filled vessels to functional ones, triggering their cavitation. We hypothesized that the cavitation resistance of xylem vessels is randomly distributed throughout the vessel network. We predicted that single vessel air injection (SVAI) vulnerability curves (VCs) would thus be affected by sample length. Longer stem samples were predicted to appear more resistant than shorter samples due to the sampled path including greater numbers of vessels. We evaluated the vessel network characteristics of grapevine (Vitis vinifera L.), English oak (Quercus robur L.) and black cottonwood (Populus trichocarpa Torr. & A. Gray), and constructed SVAI VCs for 5- and 20-cm-long segments. We also constructed VCs with a standard centrifuge method and used computer modelling to estimate the curve shift expected for pathways composed of different numbers of vessels. For all three species, the SVAI VCs for 5 cm segments rose exponentially and were more vulnerable than the 20 cm segments. The 5 cm curve shapes were exponential and were consistent with centrifuge VCs. Modelling data supported the observed SVAI VC shifts, which were related to path length and vessel network characteristics. These results suggest that exponential VCs represent the most realistic curve shape for individual vessel resistance distributions for these species. At the network level, the presence of some vessels with a higher resistance to cavitation may help avoid emboli spread during tissue dehydration.
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Affiliation(s)
- Martin D Venturas
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
- Forest Genetics and Ecophysiology Research Group (GENFOR), School of Forest Engineering, Technical University of Madrid, 28040 Madrid, Spain
| | - F Daniela Rodriguez-Zaccaro
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - Marta I Percolla
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - Casparus J Crous
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Lynnwood Road & Roper Street, Hatfield, Pretoria 0002, South Africa
| | - Anna L Jacobsen
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - R Brandon Pratt
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
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Venturas MD, MacKinnon ED, Dario HL, Jacobsen AL, Pratt RB, Davis SD. Chaparral Shrub Hydraulic Traits, Size, and Life History Types Relate to Species Mortality during California's Historic Drought of 2014. PLoS One 2016; 11:e0159145. [PMID: 27391489 PMCID: PMC4938587 DOI: 10.1371/journal.pone.0159145] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 06/28/2016] [Indexed: 11/21/2022] Open
Abstract
Chaparral is the most abundant vegetation type in California and current climate change models predict more frequent and severe droughts that could impact plant community structure. Understanding the factors related to species-specific drought mortality is essential to predict such changes. We predicted that life history type, hydraulic traits, and plant size would be related to the ability of species to survive drought. We evaluated the impact of these factors in a mature chaparral stand during the drought of 2014, which has been reported as the most severe in California in the last 1,200 years. We measured tissue water potential, native xylem specific conductivity, leaf specific conductivity, percentage loss in conductivity, and chlorophyll fluorescence for 11 species in February 2014, which was exceptionally dry following protracted drought. Mortality among the 11 dominant species ranged from 0 to 93%. Total stand density was reduced 63.4% and relative dominance of species shifted after the drought. Mortality was negatively correlated with water potential, native xylem specific conductivity, and chlorophyll fluorescence, but not with percent loss in hydraulic conductivity and leaf specific conductivity. The model that best explained mortality included species and plant size as main factors and indicated that larger plants had greater survival for 2 of the species. In general, species with greater resistance to water-stress induced cavitation showed greater mortality levels. Despite adult resprouters typically being more vulnerable to cavitation, results suggest that their more extensive root systems enable them to better access soil moisture and avoid harmful levels of dehydration. These results are consistent with the hypothesis that short-term high intensity droughts have the strongest effect on mature plants of shallow-rooted dehydration tolerant species, whereas deep-rooted dehydration avoiding species fare better in the short-term. Severe droughts can drive changes in chaparral structure as a result of the differential mortality among species.
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Affiliation(s)
- Martin D. Venturas
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, United States of America
- Grupo de Investigación en Genética, Fisiología e Historia Forestal, Universidad Politécnica de Madrid, Avda. de las Moreras s/n, 28040, Madrid, Spain
- * E-mail:
| | - Evan D. MacKinnon
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, United States of America
| | - Hannah L. Dario
- Natural Science Division, Pepperdine University, 24255 Pacific Coast Highway, Malibu, CA 90263, United States of America
| | - Anna L. Jacobsen
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, United States of America
| | - R. Brandon Pratt
- Department of Biology, California State University, 9001 Stockdale Hwy, Bakersfield, CA 93311, United States of America
| | - Stephen D. Davis
- Natural Science Division, Pepperdine University, 24255 Pacific Coast Highway, Malibu, CA 90263, United States of America
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Pereira L, Bittencourt PRL, Oliveira RS, Junior MBM, Barros FV, Ribeiro RV, Mazzafera P. Plant pneumatics: stem air flow is related to embolism - new perspectives on methods in plant hydraulics. THE NEW PHYTOLOGIST 2016; 211:357-70. [PMID: 26918522 DOI: 10.1111/nph.13905] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Accepted: 01/19/2016] [Indexed: 05/12/2023]
Abstract
Wood contains a large amount of air, even in functional xylem. Air embolisms in the xylem affect water transport and can determine plant growth and survival. Embolisms are usually estimated with laborious hydraulic methods, which can be prone to several artefacts. Here, we describe a new method for estimating embolisms that is based on air flow measurements of entire branches. To calculate the amount of air flowing out of the branch, a vacuum was applied to the cut bases of branches under different water potentials. We first investigated the source of air by determining whether it came from inside or outside the branch. Second, we compared embolism curves according to air flow or hydraulic measurements in 15 vessel- and tracheid-bearing species to test the hypothesis that the air flow is related to embolism. Air flow came almost exclusively from air inside the branch during the 2.5-min measurements and was strongly related to embolism. We propose a new embolism measurement method that is simple, effective, rapid and inexpensive, and that allows several measurements on the same branch, thus opening up new possibilities for studying plant hydraulics.
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Affiliation(s)
- Luciano Pereira
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil
| | - Paulo R L Bittencourt
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil
| | - Mauro B M Junior
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil
| | - Fernanda V Barros
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil
| | - Rafael V Ribeiro
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil
| | - Paulo Mazzafera
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil
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Knipfer T, Cuneo IF, Brodersen CR, McElrone AJ. In Situ Visualization of the Dynamics in Xylem Embolism Formation and Removal in the Absence of Root Pressure: A Study on Excised Grapevine Stems. PLANT PHYSIOLOGY 2016; 171:1024-36. [PMID: 27208267 PMCID: PMC4902599 DOI: 10.1104/pp.16.00136] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/19/2016] [Indexed: 05/17/2023]
Abstract
Gas embolisms formed during drought can disrupt long-distance water transport through plant xylem vessels, but some species have the ability to remove these blockages. Despite evidence suggesting that embolism removal is linked to the presence of vessel-associated parenchyma, the underlying mechanism remains controversial and is thought to involve positive pressure generated by roots. Here, we used in situ x-ray microtomography on excised grapevine stems to determine if embolism removal is possible without root pressure, and if the embolism formation/removal affects vessel functional status after sample excision. Our data show that embolism removal in excised stems was driven by water droplet growth and was qualitatively identical to refilling in intact plants. When stem segments were rehydrated with H2O after excision, vessel refilling occurred rapidly (<1 h). The refilling process was substantially slower when polyethylene glycol was added to the H2O source, thereby providing new support for an osmotically driven refilling mechanism. In contrast, segments not supplied with H2O showed no refilling and increased embolism formation. Dynamic changes in liquid/wall contact angles indicated that the processes of embolism removal (i.e. vessel refilling) by water influx and embolism formation by water efflux were directly linked to the activity of vessel-associated living tissue. Overall, our results emphasize that root pressure is not required as a driving force for vessel refilling, and care should be taken when performing hydraulics measurements on excised plant organs containing living vessel-associated tissue, because the vessel behavior may not be static.
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Affiliation(s)
- Thorsten Knipfer
- Department of Viticulture and Enology, University of California, Davis, California 95616 (T.K., I.F.C., A.J.M.); School of Agronomy, Pontificia Universidad Católica de Valparaíso, Quillota, Chile (I.F.C.); School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.); and United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, Davis, California 95618 (A.J.M.)
| | - Italo F Cuneo
- Department of Viticulture and Enology, University of California, Davis, California 95616 (T.K., I.F.C., A.J.M.); School of Agronomy, Pontificia Universidad Católica de Valparaíso, Quillota, Chile (I.F.C.); School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.); and United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, Davis, California 95618 (A.J.M.)
| | - Craig R Brodersen
- Department of Viticulture and Enology, University of California, Davis, California 95616 (T.K., I.F.C., A.J.M.); School of Agronomy, Pontificia Universidad Católica de Valparaíso, Quillota, Chile (I.F.C.); School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.); and United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, Davis, California 95618 (A.J.M.)
| | - Andrew J McElrone
- Department of Viticulture and Enology, University of California, Davis, California 95616 (T.K., I.F.C., A.J.M.); School of Agronomy, Pontificia Universidad Católica de Valparaíso, Quillota, Chile (I.F.C.); School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.); and United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, Davis, California 95618 (A.J.M.)
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39
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Plant hydraulic responses to long-term dry season nitrogen deposition alter drought tolerance in a Mediterranean-type ecosystem. Oecologia 2016; 181:721-31. [DOI: 10.1007/s00442-016-3609-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 03/08/2016] [Indexed: 10/22/2022]
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Pivovaroff AL, Burlett R, Lavigne B, Cochard H, Santiago LS, Delzon S. Testing the 'microbubble effect' using the Cavitron technique to measure xylem water extraction curves. AOB PLANTS 2016; 8:plw011. [PMID: 26903487 PMCID: PMC4804203 DOI: 10.1093/aobpla/plw011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/05/2016] [Indexed: 05/20/2023]
Abstract
Plant resistance to xylem cavitation is a major drought adaptation trait and is essential to characterizing vulnerability to climate change. Cavitation resistance can be determined with vulnerability curves. In the past decade, new techniques have increased the ease and speed at which vulnerability curves are produced. However, these new techniques are also subject to new artefacts, especially as related to long-vesselled species. We tested the reliability of the 'flow rotor' centrifuge technique, the so-called Cavitron, and investigated one potential mechanism behind the open vessel artefact in centrifuge-based vulnerability curves: the microbubble effect. The microbubble effect hypothesizes that microbubbles introduced to open vessels, either through sample flushing or injection of solution, travel by buoyancy or mass flow towards the axis of rotation where they artefactually nucleate cavitation. To test the microbubble effect, we constructed vulnerability curves using three different rotor sizes for five species with varying maximum vessel length, as well as water extraction curves that are constructed without injection of solution into the rotor. We found that the Cavitron technique is robust to measure resistance to cavitation in tracheid-bearing and short-vesselled species, but not for long-vesselled ones. Moreover, our results support the microbubble effect hypothesis as the major cause for the open vessel artefact in long-vesselled species.
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Affiliation(s)
- Alexandria L Pivovaroff
- La Kretz Center for California Conservation Science, University of California Los Angeles, Los Angeles, CA 90095, USA Université de Bordeaux, UMR BIOGECO, 33405 Talence, France Department of Botany and Plant Sciences, University of California Riverside, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Régis Burlett
- Université de Bordeaux, UMR BIOGECO, 33405 Talence, France
| | - Bruno Lavigne
- Université de Bordeaux, UMR BIOGECO, 33405 Talence, France
| | - Hervé Cochard
- INRA, UMR 547 PIAF, Université Clermont Auvergne, 63100 Clermont-Ferrand, France
| | - Louis S Santiago
- Department of Botany and Plant Sciences, University of California Riverside, 2150 Batchelor Hall, Riverside, CA 92521, USA
| | - Sylvain Delzon
- Université de Bordeaux, UMR BIOGECO, 33405 Talence, France INRA, UMR 1202 BIOGECO, 33612 Cestas, France
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41
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Gleason SM, Westoby M, Jansen S, Choat B, Hacke UG, Pratt RB, Bhaskar R, Brodribb TJ, Bucci SJ, Cao KF, Cochard H, Delzon S, Domec JC, Fan ZX, Feild TS, Jacobsen AL, Johnson DM, Lens F, Maherali H, Martínez-Vilalta J, Mayr S, McCulloh KA, Mencuccini M, Mitchell PJ, Morris H, Nardini A, Pittermann J, Plavcová L, Schreiber SG, Sperry JS, Wright IJ, Zanne AE. Weak tradeoff between xylem safety and xylem-specific hydraulic efficiency across the world's woody plant species. THE NEW PHYTOLOGIST 2016; 209:123-36. [PMID: 26378984 DOI: 10.1111/nph.13646] [Citation(s) in RCA: 283] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 08/13/2015] [Indexed: 05/18/2023]
Abstract
The evolution of lignified xylem allowed for the efficient transport of water under tension, but also exposed the vascular network to the risk of gas emboli and the spread of gas between xylem conduits, thus impeding sap transport to the leaves. A well-known hypothesis proposes that the safety of xylem (its ability to resist embolism formation and spread) should trade off against xylem efficiency (its capacity to transport water). We tested this safety-efficiency hypothesis in branch xylem across 335 angiosperm and 89 gymnosperm species. Safety was considered at three levels: the xylem water potentials where 12%, 50% and 88% of maximal conductivity are lost. Although correlations between safety and efficiency were weak (r(2) < 0.086), no species had high efficiency and high safety, supporting the idea for a safety-efficiency tradeoff. However, many species had low efficiency and low safety. Species with low efficiency and low safety were weakly associated (r(2) < 0.02 in most cases) with higher wood density, lower leaf- to sapwood-area and shorter stature. There appears to be no persuasive explanation for the considerable number of species with both low efficiency and low safety. These species represent a real challenge for understanding the evolution of xylem.
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Affiliation(s)
- Sean M Gleason
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
- USDA-ARS, Water Management Research, 2150 Center Ave, Build D, Suite 320, Fort Collins, CO, 80526, USA
| | - Mark Westoby
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Uwe G Hacke
- Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Robert B Pratt
- Department of Biology, California State University, Bakersfield, CA, 93311, USA
| | - Radika Bhaskar
- Department of Biology, Haverford College, 370 Lancaster Avenue, Haverford, PA, 19041, USA
| | - Tim J Brodribb
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - Sandra J Bucci
- Grupo de Estudios Biofísicos y Eco-fisiológicos (GEBEF), Universidad Nacional de la Patagonia San Juan Bosco, 9000, Comodoro Rivadavia, Argentina
| | - Kun-Fang Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, and College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi, 530004, China
| | - Hervé Cochard
- INRA, UMR547 PIAF, F-63100, Clermont-Ferrand, France
- Clermont Université, Université Blaise Pascal, UMR547 PIAF, F-63000, Clermont-Ferrand, France
| | - Sylvain Delzon
- INRA, University of Bordeaux, UMR BIOGECO, F-33450, Talence, France
| | - Jean-Christophe Domec
- Bordeaux Sciences AGRO, UMR1391 ISPA INRA, 1 Cours du général de Gaulle, 33175, Gradignan Cedex, France
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Ze-Xin Fan
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Taylor S Feild
- School of Marine and Tropical Biology, James Cook University, Townsville, Qld, 4811, Australia
| | - Anna L Jacobsen
- Department of Biology, California State University, Bakersfield, CA, 93311, USA
| | - Daniel M Johnson
- Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID, 83844, USA
| | - Frederic Lens
- Naturalis Biodiversity Center, Leiden University, PO Box 9517, 2300RA, Leiden, the Netherlands
| | - Hafiz Maherali
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G2W1, Canada
| | - Jordi Martínez-Vilalta
- CREAF, Cerdanyola del Vallès, E-08193, Barcelona, Spain
- ICREA at CREAF, Cerdanyola del Vallès, E-08193, Barcelona, Spain
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Sternwartestr. 15, 6020, Innsbruck, Austria
| | | | - Maurizio Mencuccini
- ICREA at CREAF, Cerdanyola del Vallès, E-08193, Barcelona, Spain
- School of GeoSciences, University of Edinburgh, Crew Building, West Mains Road, Edinburgh, EH9 3FF, UK
| | | | - Hugh Morris
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Andrea Nardini
- Dipartimento Scienze della Vita, Università Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Jarmila Pittermann
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95064, USA
| | - Lenka Plavcová
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - Stefan G Schreiber
- Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - John S Sperry
- Department of Biology, University of Utah, 257S 1400E, Salt Lake City, UT, 84112, USA
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Amy E Zanne
- Department of Biological Sciences, George Washington University, Science and Engineering Hall, 800 22nd Street NW, Suite 6000, Washington, DC, 20052, USA
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42
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Fukuda K, Kawaguchi D, Aihara T, Ogasa MY, Miki NH, Haishi T, Umebayashi T. Vulnerability to cavitation differs between current-year and older xylem: non-destructive observation with a compact magnetic resonance imaging system of two deciduous diffuse-porous species. PLANT, CELL & ENVIRONMENT 2015; 38:2508-18. [PMID: 25630712 DOI: 10.1111/pce.12510] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Revised: 12/30/2014] [Accepted: 01/09/2015] [Indexed: 05/26/2023]
Abstract
Development of xylem embolism during water stress in two diffuse-porous hardwoods, Katsura (Cercidiphyllum japonicum) and Japanese white birch (Betula platyphylla var. japonica), was observed non-destructively under a compact magnetic resonance imaging (MRI) system in addition to conventional quantitation of hydraulic vulnerability to cavitation from excised stem segments. Distribution of white and dark areas in MR images corresponded well to the distribution of water-filled/embolized vessels observed by cryo-scanning electron microscopy in both species. Water-filled vessels were observed in MR images as white areas in Katsura and as white dots in Japanese white birch, respectively, and embolisms could be detected as a change to dark areas. The increase in the relative embolized area (REA: %) in the cross-sectional area of total xylem during water stress, which was estimated from the binarized MR images, was consistent with the hydraulic vulnerability curves of these species. From the non-destructive MRI observations, cavitation induced by water stress was shown to develop earlier in 1- or 2-year-old xylem than in the current-year xylem in both species; that is, the vulnerability to cavitation differs between vessels in the current-year xylem and those in older annual rings.
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Affiliation(s)
- Kenji Fukuda
- Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8563, Japan
| | - Daichi Kawaguchi
- Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8563, Japan
| | - Tomo Aihara
- Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
| | - Mayumi Y Ogasa
- Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8563, Japan
| | - Naoko H Miki
- Graduate School of Environmental and Life Science, Okayama University, Okayama, 700-8530, Japan
| | | | - Toshihiro Umebayashi
- Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8563, Japan
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43
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Pivovaroff AL, Pasquini SC, De Guzman ME, Alstad KP, Stemke JS, Santiago LS. Multiple strategies for drought survival among woody plant species. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12518] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Alexandria L. Pivovaroff
- Department of Botany & Plant Sciences University of California 2150 Batchelor Hall Riverside CA 92521‐0124 USA
| | - Sarah C. Pasquini
- Department of Botany & Plant Sciences University of California 2150 Batchelor Hall Riverside CA 92521‐0124 USA
| | - Mark E. De Guzman
- Department of Botany & Plant Sciences University of California 2150 Batchelor Hall Riverside CA 92521‐0124 USA
| | - Karrin P. Alstad
- Department of Botany & Plant Sciences University of California 2150 Batchelor Hall Riverside CA 92521‐0124 USA
| | - Jenessa S. Stemke
- Department of Botany & Plant Sciences University of California 2150 Batchelor Hall Riverside CA 92521‐0124 USA
| | - Louis S. Santiago
- Department of Botany & Plant Sciences University of California 2150 Batchelor Hall Riverside CA 92521‐0124 USA
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44
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Knipfer T, Brodersen CR, Zedan A, Kluepfel DA, McElrone AJ. Patterns of drought-induced embolism formation and spread in living walnut saplings visualized using X-ray microtomography. TREE PHYSIOLOGY 2015; 35:744-55. [PMID: 26063708 DOI: 10.1093/treephys/tpv040] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/27/2015] [Indexed: 05/23/2023]
Abstract
Embolism formation and spread are dependent on conduit structure and xylem network connectivity. Detailed spatial analysis has been limited due to a lack of non-destructive methods to visualize these processes in living plants. We used synchrotron X-ray computed tomography (microCT) to visualize these processes in vivo for Juglans microcarpa Berl. saplings subjected to drought, and also evaluated embolism repair capability after re-watering. Cavitation was not detected in vivo until stem water potentials (Ψ(stem)) reached -2.2 MPa, and loss of stem hydraulic conductivity as derived from microCT images predicted that 50% of conductivity was lost at Ψ(stem) of ∼ -3.5 MPa; xylem vulnerability as determined with the centrifuge method was comparable only in the range of Ψ(stem) from -2.5 to -3.5 MPa. MicroCT images showed that cavitation appeared initially in isolated vessels not connected to other air-filled conduits. Once embolized vessels were present, multiple vessels in close proximity cavitated, and 3-D analysis along the stem axis revealed some connections between cavitated vessels. A tomography-derived automated xylem network analysis found that only 36% of vessels had one or more connections to other vessels. Cavitation susceptibility was related to vessel diameter, with large diameter vessels (>40 μm, mean diameter 25-30 μm) cavitating mainly under moderate stress (Ψ(stem) > -3 MPa) and small diameter vessels (<30 μm) under severe stress. After re-watering there was no evidence for short or longer term vessel refilling over 2 weeks despite a rapid recovery of plant water status. The low embolism susceptibility in 1-year-old J. microcarpa may aid sapling survival during establishment.
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Affiliation(s)
- Thorsten Knipfer
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
| | - Craig R Brodersen
- School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT 06511, USA
| | - Amr Zedan
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
| | - Daniel A Kluepfel
- US Department of Agriculture, Agricultural Research Service, Davis, CA 95616, USA
| | - Andrew J McElrone
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA US Department of Agriculture, Agricultural Research Service, Davis, CA 95616, USA
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45
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Venturas MD, Mackinnon ED, Jacobsen AL, Pratt RB. Excising stem samples underwater at native tension does not induce xylem cavitation. PLANT, CELL & ENVIRONMENT 2015; 38:1060-8. [PMID: 25292257 DOI: 10.1111/pce.12461] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 09/25/2014] [Indexed: 05/10/2023]
Abstract
Xylem resistance to water stress-induced cavitation is an important trait that is associated with drought tolerance of plants. The level of xylem cavitation experienced by a plant is often assessed as the percentage loss in conductivity (PLC) at different water potentials. Such measurements are constructed with samples that are excised underwater at native tensions. However, a recent study concluded that cutting conduits under significant tension induced cavitation, even when samples were held underwater during cutting. This resulted in artificially increased PLC because of what we have termed a 'tension-cutting artefact'. We tested the hypothesized tension-cutting artefact on five species by measuring PLC at native tension compared with after xylem tensions had been relaxed. Our results did not support the tension-cutting artefact hypothesis, as no differences were observed between native and relaxed samples in four of five species. In a fifth species (Laurus nobilis), differences between native and relaxed samples appear to be due to vessel refilling rather than a tension-cutting effect. We avoided the tension-cutting artefact by cutting samples to slightly longer than their measurement length and subsequent trimming of at least 0.5 cm of sample ends prior to measurement.
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Affiliation(s)
- Martin D Venturas
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA, 93311, USA
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46
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Baert A, De Schepper V, Steppe K. Variable hydraulic resistances and their impact on plant drought response modelling. TREE PHYSIOLOGY 2015; 35:439-449. [PMID: 25273815 DOI: 10.1093/treephys/tpu078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 08/17/2014] [Indexed: 06/03/2023]
Abstract
Plant drought responses are still not fully understood. Improved knowledge on drought responses is, however, crucial to better predict their impact on individual plant and ecosystem functioning. Mechanistic models in combination with plant measurements are promising for obtaining information on plant water status and can assist us in understanding the effect of limiting soil water availability and drought stress. While existing models are reliable under sufficient soil water availability, they generally fail under dry conditions as not all appropriate mechanisms seem yet to have been implemented. We therefore aimed at identifying mechanisms underlying plant drought responses, and in particular investigated the behaviour of hydraulic resistances encountered in the soil and xylem for grapevine (Vitis vinifera L.) and oak (Quercus robur L.). A variable hydraulic soil-to-stem resistance was necessary to describe plant drought responses. In addition, implementation of a variable soil-to-stem hydraulic resistance enabled us to generate an in situ soil-to-stem vulnerability curve, which might be an alternative to the conventionally used vulnerability curves. Furthermore, a daily recalibration of the model revealed a drought-induced increase in radial hydraulic resistance between xylem and elastic living tissues. Accurate information on plant hydraulic resistances and simulation of plant drought responses can foster important discussions regarding the functioning of plants and ecosystems during droughts.
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Affiliation(s)
- Annelies Baert
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
| | - Veerle De Schepper
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
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Rosner S. A new type of vulnerability curve: is there truth in vine? TREE PHYSIOLOGY 2015; 35:410-4. [PMID: 25240728 DOI: 10.1093/treephys/tpu080] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 08/17/2014] [Indexed: 05/23/2023]
Affiliation(s)
- Sabine Rosner
- Institute of Botany, BOKU Vienna, Gregor Mendel Str. 33, A-1180 Vienna, Austria
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Pratt RB, MacKinnon ED, Venturas MD, Crous CJ, Jacobsen AL. Root resistance to cavitation is accurately measured using a centrifuge technique. TREE PHYSIOLOGY 2015; 35:185-196. [PMID: 25716876 DOI: 10.1093/treephys/tpv003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Plants transport water under negative pressure and this makes their xylem vulnerable to cavitation. Among plant organs, root xylem is often highly vulnerable to cavitation due to water stress. The use of centrifuge methods to study organs, such as roots, that have long vessels are hypothesized to produce erroneous estimates of cavitation resistance due to the presence of open vessels through measured samples. The assumption that roots have long vessels may be premature since data for root vessel length are sparse; moreover, recent studies have not supported the existence of a long-vessel artifact for stems when a standard centrifuge technique was used. We examined resistance to cavitation estimated using a standard centrifuge technique and compared these values with native embolism measurements for roots of seven woody species grown in a common garden. For one species we also measured vulnerability using single-vessel air injection. We found excellent agreement between root native embolism and the levels of embolism measured using a centrifuge technique, and with air-seeding estimates from single-vessel injection. Estimates of cavitation resistance measured from centrifuge curves were biologically meaningful and were correlated with field minimum water potentials, vessel diameter (VD), maximum xylem-specific conductivity (Ksmax) and vessel length. Roots did not have unusually long vessels compared with stems; moreover, root vessel length was not correlated to VD or to the vessel length of stems. These results suggest that root cavitation resistance can be accurately and efficiently measured using a standard centrifuge method and that roots are highly vulnerable to cavitation. The role of root cavitation resistance in determining drought tolerance of woody species deserves further study, particularly in the context of climate change.
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Affiliation(s)
- R B Pratt
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - E D MacKinnon
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - M D Venturas
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
| | - C J Crous
- Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa
| | - A L Jacobsen
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA 93311, USA
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Hacke UG, Venturas MD, MacKinnon ED, Jacobsen AL, Sperry JS, Pratt RB. The standard centrifuge method accurately measures vulnerability curves of long-vesselled olive stems. THE NEW PHYTOLOGIST 2015; 205:116-27. [PMID: 25229841 DOI: 10.1111/nph.13017] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/01/2014] [Indexed: 05/02/2023]
Abstract
The standard centrifuge method has been frequently used to measure vulnerability to xylem cavitation. This method has recently been questioned. It was hypothesized that open vessels lead to exponential vulnerability curves, which were thought to be indicative of measurement artifact. We tested this hypothesis in stems of olive (Olea europea) because its long vessels were recently claimed to produce a centrifuge artifact. We evaluated three predictions that followed from the open vessel artifact hypothesis: shorter stems, with more open vessels, would be more vulnerable than longer stems; standard centrifuge-based curves would be more vulnerable than dehydration-based curves; and open vessels would cause an exponential shape of centrifuge-based curves. Experimental evidence did not support these predictions. Centrifuge curves did not vary when the proportion of open vessels was altered. Centrifuge and dehydration curves were similar. At highly negative xylem pressure, centrifuge-based curves slightly overestimated vulnerability compared to the dehydration curve. This divergence was eliminated by centrifuging each stem only once. The standard centrifuge method produced accurate curves of samples containing open vessels, supporting the validity of this technique and confirming its utility in understanding plant hydraulics. Seven recommendations for avoiding artefacts and standardizing vulnerability curve methodology are provided.
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Affiliation(s)
- Uwe G Hacke
- Department of Renewable Resources, University of Alberta, Edmonton, AB, T6G 2E3, Canada
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Torres-Ruiz JM, Jansen S, Choat B, McElrone AJ, Cochard H, Brodribb TJ, Badel E, Burlett R, Bouche PS, Brodersen CR, Li S, Morris H, Delzon S. Direct x-ray microtomography observation confirms the induction of embolism upon xylem cutting under tension. PLANT PHYSIOLOGY 2015; 167:40-3. [PMID: 25378693 PMCID: PMC4281005 DOI: 10.1104/pp.114.249706] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 11/05/2014] [Indexed: 05/17/2023]
Abstract
Direct visualization shows enhanced embolism of xylem samples when they are collected under tension .
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Affiliation(s)
- José M Torres-Ruiz
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Steven Jansen
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Brendan Choat
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Andrew J McElrone
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Hervé Cochard
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Timothy J Brodribb
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Eric Badel
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Regis Burlett
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Pauline S Bouche
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Craig R Brodersen
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Shan Li
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Hugh Morris
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
| | - Sylvain Delzon
- Université de Bordeaux, BIOGECO, Unité Mixte de Recherche 1202, F-33615 Pessac, France (J.M.T.-R., R.B., P.S.B., S.D.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1202 BIOGECO, F-33610 Cestas, France (J.M.T.-R., R.B., P.S.B., S.D.);Ulm University, Institute of Systematic Botany and Ecology, D-89081 Ulm, Germany (S.J., P.S.B., S.L., H.M.);University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, New South Wales 2753, Australia (B.C.);United States Department of Agriculture-Agricultural Research Service, Crops Pathology and Genetics Research Unit, University of California, Davis, California 95616 (A.J.M.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, 63100 Clermont-Ferrand, France (H.C., E.B.);Clermont Université, Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (H.C., E.B.);School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia (T.J.B.); andSchool of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
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