1
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Zhang Y, Pereira L, Kaack L, Liu J, Jansen S. Gold perfusion experiments support the multi-layered, mesoporous nature of intervessel pit membranes in angiosperm xylem. THE NEW PHYTOLOGIST 2024; 242:493-506. [PMID: 38404029 DOI: 10.1111/nph.19608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 01/30/2024] [Indexed: 02/27/2024]
Abstract
Fluid transport across intervessel pit membranes of angiosperm xylem plays a major role in plant transpiration, with transport resistance largely depending on pore constriction sizes. Traditionally, fluid particles traversing pit membranes are assumed to cross a single instead of multiple pore constrictions. We tested a multi-layered pit membrane model in xylem of eight angiosperm species by estimating the size frequency of pore constrictions in relation to pit membrane thickness and compared modelled data with perfusion characteristics of nanoscale gold particles based on transmission electron microscopy. The size frequency of modelled pore constrictions showed similar patterns to the measured number of perfused particle sizes inside pit membranes, although frequency values measured were 10-50 times below modelled data. Small particles enter pit membranes most easily, especially when injected in thin pit membranes. The trapping of gold particles by pore constrictions becomes more likely with increasing pore constriction number and pit membrane thickness. While quantitative differences between modelled and experimental data are due to various practical limitations, their qualitative agreement supports a multi-layered pit membrane model with multiple pore constrictions. Pore constrictions between 5 and 50 nm are realistic, and confirm the mesoporous nature of pit membranes.
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Affiliation(s)
- Ya Zhang
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal University, Beijingzhong Road 2, Wuhu, 241000, China
| | - Luciano Pereira
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm, D-89081, Germany
| | - Lucian Kaack
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm, D-89081, Germany
| | - Jiabao Liu
- College of Ecology and Environment, Anhui Normal University, Beijingzhong Road 2, Wuhu, 241000, China
| | - Steven Jansen
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm, D-89081, Germany
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2
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Wei Y, Chen YJ, Siddiq Z, Zhang JL, Zhang SB, Jansen S, Cao KF. Hydraulic traits and photosynthesis are coordinated with trunk sapwood capacitance in tropical tree species. TREE PHYSIOLOGY 2023; 43:2109-2120. [PMID: 37672225 DOI: 10.1093/treephys/tpad107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 08/28/2023] [Indexed: 09/07/2023]
Abstract
Water stored in trunk sapwood is vital for the canopy to maintain its physiological function under high transpiration demands. Little is known regarding the anatomical properties that contribute to the hydraulic capacitance of tree trunks and whether trunk capacitance is correlated with the hydraulic and gas exchange traits of canopy branches. We examined sapwood capacitance, xylem anatomical characteristics of tree trunks, embolism resistance, the minimal xylem water potential of canopy branches, leaf photosynthesis and stomatal conductance in 22 species from a tropical seasonal rainforest and savanna. The results showed that the mean trunk sapwood capacitance did not differ between the two biomes. Capacitance was closely related to the fiber lumen fraction and fiber wall reinforcement and not to the axial and ray parenchyma fractions. Additionally, it was positively correlated with the theoretical hydraulic conductivity of a trunk and the specific hydraulic conductivity of branches, and showed a trade-off with branch embolism resistance. Species with a high trunk sapwood capacitance maintained less negative canopy water potentials in the dry season, but higher leaf photosynthetic rates and stomatal conductance in the wet season. This study provides a functional link among trunk sapwood capacitance, xylem anatomy, canopy hydraulics and photosynthesis in tropical trees.
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Affiliation(s)
- Yang Wei
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
| | - Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang 653300, Yunnan, China
| | - Zafar Siddiq
- Department of Botany, Government College University, Katchery Road, Lahore 54000, Punjab, Pakistan
| | - Jiao-Lin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303, Yunnan, China
| | - Steven Jansen
- Institute of Botany, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Baden-Wurttemberg, Germany
| | - Kun-Fang Cao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, NO. 100 Daxuedonglu, Nanning 530004, Guangxi, China
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Xiang Y, Kagawa A, Nagai S, Yasuda Y, Utsumi Y. The difference in the functional water flow network between the stem and current-year root cross-sectional surfaces in Salix gracilistyla stem xylem. TREE PHYSIOLOGY 2023; 43:1326-1340. [PMID: 37098160 DOI: 10.1093/treephys/tpad056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 04/17/2023] [Accepted: 04/21/2023] [Indexed: 06/19/2023]
Abstract
The dye injection method has been applied to many species to analyze the xylem water transport pathway in trees. However, traditional dye injection methods introduced dye tracers from the surface of cut stems, including several annual rings. Furthermore, the traditional dye injection method did not evaluate radial water movement from the outermost annual rings to the inner annual rings. In this study, we assessed the difference in radial water movement visualized by an injected dye, between stem base cut and current-year root cut samples of Salix gracilistyla Miq., with current-year roots grown hydroponically. The results showed that the number of stained annual rings in the root cut samples was smaller than that in the stem cut samples, and the percentage of stained vessels in the root cut samples was significantly smaller than that in the stem base cut samples in the second and third annual rings. In the current-year root cut samples, water transport mainly occurred in the outermost rings from the current-year roots to leaves. In addition, the theoretical hydraulic conductivity of stained vessels in the stem cut samples was higher in the current-year root cut samples in the second and third annual rings. These findings indicate that the previously reported dye injection method using stem cut samples overestimated the water transport pathway in the inner part of the stems. Moreover, previous hydraulic conductivity measurement methods might not have considered the effects of radial resistance through the annual ring boundary, and they might have overestimated the hydraulic conductivity in the inner annual rings.
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Affiliation(s)
- Yan Xiang
- Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi Ward, Fukuoka city, Fukuoka, 819-0385, Japan
| | - Akira Kagawa
- Forestry and Forest Products Research Institute, Wood Anatomy and Quality Laboratory, 1 Matsunosato, Tsukuba, Ibaraki 300-1244, Japan
| | - Satoshi Nagai
- Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Forestry and Forest Products Research Institute, 430 Yamasakicho Ikaba, Shiso, Hyogo 671-2515, Japan
| | - Yuko Yasuda
- Department of Environmental Sciences and Technology, Faculty of Agriculture, Kagoshima University, 1 Chome-21-24 Korimoto, Kagoshima City Kagoshima, 890-0065, Japan
| | - Yasuhiro Utsumi
- Kyushu University Forest, Kyushu University, 394-1 Tsubakuro, Sasaguri, Kasuya District, Fukuoka 811-2415, Japan
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Yan C, Zhang N, Xu C, Jin Q, Qi Y, Cai Y. Effects on stone cell development and lignin deposition in pears by different pollinators. FRONTIERS IN PLANT SCIENCE 2023; 14:1093661. [PMID: 36844042 PMCID: PMC9944722 DOI: 10.3389/fpls.2023.1093661] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
INTRODUCTION The pear pulp is formed by the development of the ovary wall, which is the somatic cell of the female parent, and its genetic traits are identical to those of the female parent, so that its phenotypic traits should also be identical to those of the female parent. However, the pulp quality of most pears, especially the stone cell clusters (SCCs) number and degree of polymerization (DP), were significantly affected by the paternal type. Stone cells are formed by the deposition of lignin in parenchymal cell (PC) walls. Studies on the effect of pollination on lignin deposition and stone cell formation in pear fruit have not been reported. Methods: In this study, 'Dangshan Su' (P. bretschneideri Rehd.) was selected as the mother tree, while 'Yali' (P. bretschneideri Rehd.) and 'Wonhwang' (P. pyrifolia Nakai.) were used as the father trees to perform cross-pollination. We investigated the effects of different parents on SCCs number and DP, and lignin deposition by microscopic and ultramicroscopic observation. RESULTS AND DISCUSSION The results showed that the formation of SCCs proceeds was consistent in DY and DW, but the SCC number and DP in DY were higher than that in DW. Ultramicroscopy revealed that the lignification process of DY and DW were all from corner to rest regions of the compound middle lamella and the secondary wall, with lignin particles deposited along the cellulose microfibrils. They were alternatively arranged until they filled up the whole cell cavity to culminate in the formation of stone cells. However, the compactness of the wall layer of cell wall was significantly higher in DY than in DW. We also found that the pit of stone cell was predominantly single pit pair, they transported degraded material from the PCs that were beginning to lignify out of the cells. Stone cell formation and lignin deposition in pollinated pear fruit from different parents were consistent, but the DP of SCCs and the compactness of the wall layer were higher in DY than that in DW. Therefore, DY SCC had a higher ability to resist the expansion pressure of PC.
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Affiliation(s)
- Chongchong Yan
- Anhui Academy of Agricultural Sciences, Hefei, Anhui, China
- Insititute of Horticulture, Anhui Academy of Agricultural Sciences, Key Laboratory of Horticultural Crop Germplasm innovation and Utilization (Co-construction by Ministry and Province), Hefei, Anhui, China
| | - Nan Zhang
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, China
- College of Health and Elderly, Anhui Vocational College of City Management, Hefei, Anhui, China
| | - Chao Xu
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, China
| | - Qing Jin
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, China
| | - Yongjie Qi
- Anhui Academy of Agricultural Sciences, Hefei, Anhui, China
- Insititute of Horticulture, Anhui Academy of Agricultural Sciences, Key Laboratory of Horticultural Crop Germplasm innovation and Utilization (Co-construction by Ministry and Province), Hefei, Anhui, China
| | - Yongping Cai
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, China
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Carmesin CF, Port F, Böhringer S, Gottschalk KE, Rasche V, Jansen S. Ageing-induced shrinkage of intervessel pit membranes in xylem of Clematis vitalba modifies its mechanical properties as revealed by atomic force microscopy. FRONTIERS IN PLANT SCIENCE 2023; 14:1002711. [PMID: 36755701 PMCID: PMC9899931 DOI: 10.3389/fpls.2023.1002711] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/05/2023] [Indexed: 06/18/2023]
Abstract
Bordered pit membranes of angiosperm xylem are anisotropic, mesoporous media between neighbouring conduits, with a key role in long distance water transport. Yet, their mechanical properties are poorly understood. Here, we aim to quantify the stiffness of intervessel pit membranes over various growing seasons. By applying an AFM-based indentation technique "Quantitative Imaging" we measured the effective elastic modulus (E effective) of intervessel pit membranes of Clematis vitalba in dependence of size, age, and hydration state. The indentation-deformation behaviour was analysed with a non-linear membrane model, and paired with magnetic resonance imaging to visualise sap-filled and embolised vessels, while geometrical data of bordered pits were obtained using electron microscopy. E effective was transformed to the geometrically independent apparent elastic modulus E apparent and to aspiration pressure P b. The material stiffness (E apparent) of fresh pit membranes was with 57 MPa considerably lower than previously suggested. The estimated pressure for pit membrane aspiration was 2.20+28 MPa. Pit membranes from older growth rings were shrunken, had a higher material stiffness and a lower aspiration pressure than current year ones, suggesting an irreversible, mechanical ageing process. This study provides an experimental-stiffness analysis of hydrated intervessel pit membranes in their native state. The estimated aspiration pressure suggests that membranes are not deflected under normal field conditions. Although absolute values should be interpreted carefully, our data suggest that pit membrane shrinkage implies increasing material stiffness, and highlight the dynamic changes of pit membrane mechanics and their complex, functional behaviour for fluid transport.
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Affiliation(s)
- Cora F. Carmesin
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
| | - Fabian Port
- Institute of Experimental Physics, Ulm University, Albert Einstein Allee 45, Ulm, Germany
| | - Samuel Böhringer
- Institut für Quantenphysik and Center for Integrated Quantum Science and Technology, Universität Ulm, Albert-Einstein-Allee 11, Ulm, Germany
| | | | - Volker Rasche
- Core Facility Small Animal Imaging, Medical Faculty, Ulm University, Ulm, Germany
- Department of Internal Medicine II, Ulm University, Albert Einstein Allee 45, Ulm, Germany
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
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Avila RT, Kane CN, Batz TA, Trabi C, Damatta FM, Jansen S, McAdam SAM. The relative area of vessels in xylem correlates with stem embolism resistance within and between genera. TREE PHYSIOLOGY 2023; 43:75-87. [PMID: 36070431 DOI: 10.1093/treephys/tpac110] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
The resistance of xylem conduits to embolism is a major factor defining drought tolerance and can set the distributional limits of species across rainfall gradients. Recent work suggests that the proximity of vessels to neighbors increases the vulnerability of a conduit. We therefore investigated whether the relative vessel area of xylem correlates with intra- and inter-generic variation in xylem embolism resistance in species pairs or triplets from the genera Acer, Cinnamomum, Ilex, Quercus and Persea, adapted to environments differing in aridity. We used the optical vulnerability method to assess embolism resistance in stems and conducted anatomical measurements on the xylem in which embolism resistance was quantified. Vessel lumen fraction (VLF) correlated with xylem embolism resistance across and within genera. A low VLF likely increases the resistance to gas movement between conduits, by diffusion or advection, whereas a high VLF enhances gas transport thorough increased conduit-to-conduit connectivity and reduced distances between conduits and therefore the likelihood of embolism propagation. We suggest that the rate of gas movement due to local pressure differences and xylem network connectivity is a central driver of embolism propagation in angiosperm vessels.
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Affiliation(s)
- Rodrigo T Avila
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
- Department of Botany and Plant Pathology, Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Cade N Kane
- Department of Botany and Plant Pathology, Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Timothy A Batz
- Department of Botany and Plant Pathology, Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Christophe Trabi
- Faculty of Natural Sciences, Institute of Systematic Botany and Ecology, Ulm University, Ulm, Baden-Württemberg 89081, Germany
| | - Fábio M Damatta
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Steven Jansen
- Faculty of Natural Sciences, Institute of Systematic Botany and Ecology, Ulm University, Ulm, Baden-Württemberg 89081, Germany
| | - Scott A M McAdam
- Department of Botany and Plant Pathology, Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
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Echeverría A, Petrone‐Mendoza E, Segovia‐Rivas A, Figueroa‐Abundiz VA, Olson ME. The vessel wall thickness-vessel diameter relationship across woody angiosperms. AMERICAN JOURNAL OF BOTANY 2022; 109:856-873. [PMID: 35435252 PMCID: PMC9328290 DOI: 10.1002/ajb2.1854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 05/26/2023]
Abstract
PREMISE Comparative anatomy is necessary to identify the extremes of combinations of functionally relevant structural traits, to ensure that physiological data cover xylem anatomical diversity adequately, and thus achieve a global understanding of xylem structure-function relations. A key trait relationship is that between xylem vessel diameter and wall thickness of both the single vessel and the double vessel+adjacent imperforate tracheary element (ITE). METHODS We compiled a comparative data set with 1093 samples, 858 species, 350 genera, 86 families, and 33 orders. We used broken linear regression and an algorithm to explore changes in parameter values from linear regressions using subsets of the data set to identify a threshold, at 90-µm vessel diameter, in the wall thickness-diameter relationship. RESULTS Below 90 µm diameter for vessels, virtually any wall thickness could be associated with virtually any diameter. Below this threshold, selection is free to favor a very wide array of combinations, such as very thick walls and narrow vessels in ITE-free herbs, or very thin-walled, wide vessels in evergreen dryland pioneers. Above 90 µm, there was a moderate positive relationship. CONCLUSIONS Our analysis shows that the space of vessel wall thickness-diameter combinations is very wide, with selection apparently eliminating individuals with vessel walls "too thin" for their diameter. Most importantly, our survey revealed poorly studied plant hydraulic syndromes (functionally significant trait combinations). These data suggest that the full span of trait combinations, and thus the minimal set of hydraulic syndromes requiring study to span woody plant functional diversity adequately, remains to be documented.
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Affiliation(s)
- Alberto Echeverría
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510México
| | - Emilio Petrone‐Mendoza
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510México
| | - Alí Segovia‐Rivas
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510México
| | - Víctor A. Figueroa‐Abundiz
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510México
| | - Mark E. Olson
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510México
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Barigah TS, Gyenge JE, Barreto F, Rozenberg P, Fernández ME. Narrow vessels cavitate first during a simulated drought in Eucalyptus camaldulensis. PHYSIOLOGIA PLANTARUM 2021; 173:2081-2090. [PMID: 34523145 DOI: 10.1111/ppl.13556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 09/06/2021] [Indexed: 06/13/2023]
Abstract
Establishing drying-limits for mortality of different tree species and understanding the anatomical and physiological traits involved is crucial to predict forests' responses to climate change. The xylem of Eucalyptus camaldulensis presents a complex of solitary vessels surrounded by different imperforate tracheary elements and parenchyma that influence, in a poorly known way, its hydraulic functioning. We aimed at describing the dynamics of embolism propagation in this type of xylem, seeking any vessel-size pattern, and unraveling the threshold of xylem embolism leading to nonrecovery after drought in E. camaldulensis. We assigned potted saplings to a protracted water-stress for 70 days. We relied on colorimetric and hydraulic methods to test for links between xylem anatomy and embolism propagation in the main stem. On average, the occurrence of embolism was randomly distributed in the stem xylem, but the probability of embolized vessels was higher than predicted by chance in the narrowest vessels of individuals that experienced low to moderate water-stress. The saplings could recover from severe water-stress if their percentage loss of conductance (PLC) was <77%, but not when the PLC was ˃ 85%. We concluded that, contrary to results reported for most species, the narrowest vessels are the most vulnerable to cavitation in E. camaldulensis, suggesting a lack of tradeoff between xylem efficiency and safety (in response to drought) at the tissue level. These results challenge the well-established paradigm of the effect of vessel size on cavitation, which states that the widest conduits are the most vulnerable to both freeze-thaw and drought-induced cavitation.
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Affiliation(s)
| | - Javier Enrique Gyenge
- CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- INTA, Instituto Nacional de Tecnología Agropecuaria, Ecología Forestal, UEDD INTA-CONICET IPADS, Tandil, Argentina
| | - Florencia Barreto
- CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | | | - María Elena Fernández
- CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- INTA, Instituto Nacional de Tecnología Agropecuaria, Ecología Forestal, UEDD INTA-CONICET IPADS, Tandil, Argentina
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9
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Mrad A, Johnson DM, Love DM, Domec JC. The roles of conduit redundancy and connectivity in xylem hydraulic functions. THE NEW PHYTOLOGIST 2021; 231:996-1007. [PMID: 33908055 DOI: 10.1111/nph.17429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
Wood anatomical traits shape a xylem segment's hydraulic efficiency and resistance to embolism spread due to declining water potential. It has been known for decades that variations in conduit connectivity play a role in altering xylem hydraulics. However, evaluating the precise effect of conduit connectivity has been elusive. The objective here is to establish an analytical linkage between conduit connectivity and grouping and tissue-scale hydraulics. It is hypothesized that an increase in conduit connectivity brings improved resistance to embolism spread due to increased hydraulic pathway redundancy. However, an increase in conduit connectivity could also reduce resistance due to increased speed of embolism spread with respect to pressure. We elaborate on this trade-off using graph theory, percolation theory and computational modeling of xylem. The results are validated using anatomical measurements of Acer branch xylem. Considering only species with vessels, increases in connectivity improve resistance to embolism spread without negatively affecting hydraulic conductivity. The often measured grouping index fails to capture the totality of the effect of conduit connectivity on xylem hydraulics. Variations in xylem network characteristics, such as conduit connectivity, might explain why hypothesized trends among woody species, such as the 'safety-efficiency' trade-off hypothesis, are weaker than expected.
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Affiliation(s)
- Assaad Mrad
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
- Department of Civil and Environmental Engineering, University of California, Irvine, CA, 92697, USA
- Department of Engineering, Wake Forest University, Winston-Salem, NC, 27101, USA
| | - Daniel M Johnson
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA
| | - David M Love
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA
| | - Jean-Christophe Domec
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
- Bordeaux Sciences Agro, UMR 1391 INRA-ISPA, Gradignan Cedex, 33175, France
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10
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Trabi CL, Pereira L, Guan X, Miranda MT, Bittencourt PRL, Oliveira RS, Ribeiro RV, Jansen S. A User Manual to Measure Gas Diffusion Kinetics in Plants: Pneumatron Construction, Operation, and Data Analysis. FRONTIERS IN PLANT SCIENCE 2021; 12:633595. [PMID: 34163496 PMCID: PMC8216216 DOI: 10.3389/fpls.2021.633595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/12/2021] [Indexed: 05/17/2023]
Abstract
The Pneumatron device measures gas diffusion kinetics in the xylem of plants. The device provides an easy, low-cost, and powerful tool for research on plant water relations and gas exchange. Here, we describe in detail how to construct and operate this device to estimate embolism resistance of angiosperm xylem, and how to analyse pneumatic data. Simple and more elaborated ways of constructing a Pneumatron are shown, either using wires, a breadboard, or a printed circuit board. The instrument is based on an open-source hardware and software system, which allows users to operate it in an automated or semi-automated way. A step-by-step manual and a troubleshooting section are provided. An excel spreadsheet and an R-script are also presented for fast and easy data analysis. This manual aims at helping users to avoid common mistakes, such as unstable measurements of the minimum and maximum amount of gas discharged from xylem tissue, which has major consequences for estimating embolism resistance. Major advantages of the Pneumatron device include its automated and accurate measurements of gas diffusion rates, including highly precise measurements of the gas volume in intact, embolised conduits. It is currently unclear if the method can also be applied to woody monocots, gymnosperm species that possess torus-margo pit membranes, or to herbaceous species.
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Affiliation(s)
| | - Luciano Pereira
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
- Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, Brazil
- Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Xinyi Guan
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - Marcela T. Miranda
- Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, Brazil
| | | | - Rafael S. Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Rafael V. Ribeiro
- Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
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11
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Guan X, Pereira L, McAdam SAM, Cao KF, Jansen S. No gas source, no problem: Proximity to pre-existing embolism and segmentation affect embolism spreading in angiosperm xylem by gas diffusion. PLANT, CELL & ENVIRONMENT 2021; 44:1329-1345. [PMID: 33529382 DOI: 10.1111/pce.14016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/16/2021] [Accepted: 01/17/2021] [Indexed: 05/12/2023]
Abstract
Embolism spreading in dehydrating angiosperm xylem is driven by gas movement between embolized and sap-filled conduits. Here we examine how the proximity to pre-existing embolism and hydraulic segmentation affect embolism propagation. Based on the optical method, we compare xylem embolism resistance between detached leaves and leaves attached to branches, and between intact leaves and leaves with cut minor veins, for six species. Embolism resistance of detached leaves was significantly lower than that of leaves attached to stems, except for two species, with all vessels ending in their petioles. Cutting of minor veins showed limited embolism spreading in minor veins near the cuts prior to major veins. Moreover, despite strong agreement in the overall embolism resistance of detached leaves between the optical and pneumatic method, minor differences were observed during early stages of embolism formation. We conclude that embolism resistance may represent a relative trait due to an open-xylem artefact, with embolism spreading possibly affected by the proximity and connectivity to pre-existing embolism as a gas source, while hydraulic segmentation prevents such artefact. Since embolism formation may not rely on a certain pressure difference threshold between functional and embolized conduits, we speculate that embolism is facilitated by pressure-driven gas diffusion across pit membranes.
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Affiliation(s)
- Xinyi Guan
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - Luciano Pereira
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
- Laboratory of Plant Physiology "Coaracy M. Franco", Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, Brazil
- Laboratory of Crop Physiology, Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Scott A M McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, USA
| | - Kun-Fang Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilisation of Subtropical Agro-Bioresources, Guangxi University, Nanning, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
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12
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McElrone AJ, Manuck CM, Brodersen CR, Patakas A, Pearsall KR, Williams LE. Functional hydraulic sectoring in grapevines as evidenced by sap flow, dye infusion, leaf removal and micro-computed tomography. AOB PLANTS 2021; 13:plab003. [PMID: 33841756 PMCID: PMC8023307 DOI: 10.1093/aobpla/plab003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 01/08/2021] [Indexed: 05/24/2023]
Abstract
The supply of water to a plant canopy is dependent on the xylem pathway connecting roots to leaves. In some plants, sectored xylem pathways can restrict resource distribution, resulting in variable quality of organs in the shoots, yet little is known about the effects of sectoring in crop cultivars. In this study, we combined sap flow measurements and infusion of xylem-specific dyes to document functional conductive area and flow pathways from roots to shoots of 20-year-old Thompson Seedless and 8-year-old Chardonnay grapevines. Sap flow measurements and dye infusion demonstrated that water flowed predominantly in discrete xylem (visually identifiable from the trunk surface) sectors along the trunk axis, each supplying limited portions of the canopy. Functional conductive area in the trunk was proportional to that in the shoots even though sector size varied considerably between vines. Leaf area removal experiments further demonstrated sectoring in grapevines; sap flow decreased by >90 % in trunk sectors connected to excised shoots while it remained constant in trunk sectors supplying intact portions of the canopy. Despite the functional sectoring in grapevines, a high degree of interconnectivity of trunk xylem in the tangential direction was confirmed with synchrotron-based micro-computed tomography (microCT) and dye crossover infusion studies. Fruit attached to dyed canes was also similarly sectored; no clusters exhibited dye on non-dyed canes, while 97 % of clusters attached to dyed canes exhibited dye infusion. The dye travelled down the cluster rachis and appeared to accumulate at the pedicel/berry junction, but only on dyed canes. These findings suggest that xylem in grapevine trunks is integrated anatomically, but functions in a sectored manner due to high axial hydraulic conductivity. The functional sectoring of grapevine xylem documented here has important implications for management practices in vineyards and for fruit cluster uniformity within single grapevine.
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Affiliation(s)
- A J McElrone
- USDA-ARS, Crops Pathology and Genetics Research Unit, Davis, CA 95616, USA
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
| | - C M Manuck
- USDA-ARS, Crops Pathology and Genetics Research Unit, Davis, CA 95616, USA
| | | | - A Patakas
- University of Ioannina, Ioannina, 451 10, Greece
| | - K R Pearsall
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
| | - L E Williams
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
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13
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Levionnois S, Jansen S, Wandji RT, Beauchêne J, Ziegler C, Coste S, Stahl C, Delzon S, Authier L, Heuret P. Linking drought-induced xylem embolism resistance to wood anatomical traits in Neotropical trees. THE NEW PHYTOLOGIST 2021; 229:1453-1466. [PMID: 32964439 DOI: 10.1111/nph.16942] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/04/2020] [Indexed: 05/27/2023]
Abstract
Drought-induced xylem embolism is considered to be one of the main factors driving mortality in woody plants worldwide. Although several structure-functional mechanisms have been tested to understand the anatomical determinants of embolism resistance, there is a need to study this topic by integrating anatomical data for many species. We combined optical, laser, and transmission electron microscopy to investigate vessel diameter, vessel grouping, and pit membrane ultrastructure for 26 tropical rainforest tree species across three major clades (magnoliids, rosiids, and asteriids). We then related these anatomical observations to previously published data on drought-induced embolism resistance, with phylogenetic analyses. Vessel diameter, vessel grouping, and pit membrane ultrastructure were all predictive of xylem embolism resistance, but with weak predictive power. While pit membrane thickness was a predictive trait when vestured pits were taken into account, the pit membrane diameter-to-thickness ratio suggests a strong importance of the deflection resistance of the pit membrane. However, phylogenetic analyses weakly support adaptive coevolution. Our results emphasize the functional significance of pit membranes for air-seeding in tropical rainforest trees, highlighting also the need to study their mechanical properties due to the link between embolism resistance and pit membrane diameter-to-thickness ratio. Finding support for adaptive coevolution also remains challenging.
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Affiliation(s)
- Sébastien Levionnois
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- UMR AMAP, Université de Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, D-89081, Germany
| | - Ruth Tchana Wandji
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Jacques Beauchêne
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- AgroParisTech, UMR Silva, INRAE, Université de Lorraine, Nancy, F-54000, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Sylvain Delzon
- UMR BIOGECO, INRAE, Université de Bordeaux, Pessac, 33615, France
| | - Louise Authier
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Patrick Heuret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
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14
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Olson ME. From Carlquist's ecological wood anatomy to Carlquist's Law: why comparative anatomy is crucial for functional xylem biology. AMERICAN JOURNAL OF BOTANY 2020; 107:1328-1341. [PMID: 33078405 DOI: 10.1002/ajb2.1552] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
All students of xylem structure-function relations need to be familiar with the work of Sherwin Carlquist. He studies xylem through the lens of the comparative method, which uses the appearance of similar anatomical features under similar conditions of natural selection to infer function. "Function" in biology implies adaptation; maximally supported adaptation inferences require experimental and comparative xylem scientists to work with one another. Engaging with comparative inferences of xylem function will, more likely sooner rather than later, bring one to the work of Sherwin Carlquist. To mark his 90th birthday, I highlight just a few examples of his extraordinarily perceptive and general comparative insights. One is "Carlquist's Law", the pervasive tendency for vessels to be solitary when background cells are conductive. I cover his pioneering of "ecological" wood anatomy, viewing xylem variation as reflecting the effects of selection across climate and habit variation. Another is the embolism vulnerability-conduit diameter relationship, one of the most widely invoked structure-function relationships in xylem biology. I discuss the inferential richness within the notion of Carlquistian paedomorphosis, including detailed functional inferences regarding ray cell orientation. My final example comes from his very recent work offering the first satisfactory hypothesis accounting for the geographical and histological distribution of scalariform perforation plates as an adaptation, including "Carlquist's Ratchet", why scalariform plates are adaptive but do not re-evolve once lost. This extraordinarily rich production over six decades is filled with comparative inferences that should keep students of xylem function busy testing for decades to come.
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Affiliation(s)
- Mark E Olson
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Mexico, DF, 04510, México
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15
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Yazaki K, Levia DF, Takenouchi A, Watanabe M, Kabeya D, Miki NH, Taneda H, Ogasa MY, Oguro M, Saiki S, Tobita H, Fukuda K. Imperforate tracheary elements and vessels alleviate xylem tension under severe dehydration: insights from water release curves for excised twigs of three tree species. AMERICAN JOURNAL OF BOTANY 2020; 107:1122-1135. [PMID: 32779767 PMCID: PMC7496847 DOI: 10.1002/ajb2.1518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
PREMISE Water stored in the xylem of woody plants is important for supporting the transpiration stream under prolonged drought, yet the source of stored water within the xylem during drought remains unclear. Insights into xylem water utilization during drought will uncover the adaptation strategies of the test species to stress. METHODS To fill the existing knowledge gap, we excised twigs of Abies firma (Japanese fir, conifer), Cercidiphyllum japonicum (katsura tree, diffuse-porous) and Quercus serrata (konara oak, ring-porous) to quantify interspecific variation of water transfer in xylem corresponding with increasing cumulative water release (CWR) using micro x-ray computed tomography and cryo-SEM. RESULTS For all species studied, the main components of water storage within the operating range of water potential were not living cells but cavitation release and capillaries. Abies firma maintained water in the earlywood-like cells, for possible maintenance of the transpiration stream. Cercidiphyllum japonicum maintained water in its vessels over 200 kg m-3 of CWR, while Q. serrata lost most of its water in vessels with increasing CWR up to 100 kg m-3 . Cercidiphyllum japonicum exhibited a higher water storage capacity than Q. serrata. Under high CWR, narrow conduits stored xylem water in C. japonicum and imperforate tracheary elements in Q. serrata. CONCLUSIONS Among the species examined, increasing CWR appears to indicate differential utilization of stored water in relation to variation of xylem structure, thereby providing insight into the interspecific responses of tree species to drought.
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Affiliation(s)
- Kenichi Yazaki
- Department of Plant EcologyForestry and Forest Products Research Institute (FFPRI)TsukubaIbaraki305‐8687Japan
| | - Delphis F. Levia
- Departments of Geography & Spatial Sciences and Plant & Soil SciencesUniversity of DelawareNewarkDE19716USA
| | - Akiko Takenouchi
- Research Center for Structural MaterialsNational Institute of Materials Science (NIMS)TsukubaIbaraki305‐0047Japan
| | - Makoto Watanabe
- Research Center for Structural MaterialsNational Institute of Materials Science (NIMS)TsukubaIbaraki305‐0047Japan
| | - Daisuke Kabeya
- Department of Plant EcologyForestry and Forest Products Research Institute (FFPRI)TsukubaIbaraki305‐8687Japan
| | - Naoko H. Miki
- Graduate School of Environmental and Life ScienceOkayama UniversityOkayama700‐8530Japan
| | - Haruhiko Taneda
- Graduate School of ScienceThe University of TokyoTokyo113‐0033Japan
| | - Mayumi Y. Ogasa
- Kansai Research CenterForestry and Forest Products Research Institute (FFPRI)KyotoKyoto612‐0855Japan
| | - Michio Oguro
- Department of Forest VegetationForestry and Forest Products Research Institute (FFPRI)TsukubaIbaraki305‐8687Japan
| | - Shin‐Taro Saiki
- Department of Plant EcologyForestry and Forest Products Research Institute (FFPRI)TsukubaIbaraki305‐8687Japan
| | - Hiroyuki Tobita
- Department of Plant EcologyForestry and Forest Products Research Institute (FFPRI)TsukubaIbaraki305‐8687Japan
| | - Kenji Fukuda
- Graduate School of Agricultural and Life SciencesThe University of TokyoTokyo113‐8657Japan
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16
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Olson M, Rosell JA, Martínez‐Pérez C, León‐Gómez C, Fajardo A, Isnard S, Cervantes‐Alcayde MA, Echeverría A, Figueroa‐Abundiz VA, Segovia‐Rivas A, Trueba S, Vázquez‐Segovia K. Xylem vessel‐diameter–shoot‐length scaling: ecological significance of porosity types and other traits. ECOL MONOGR 2020. [DOI: 10.1002/ecm.1410] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Mark Olson
- Instituto de Biología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
| | - Julieta A. Rosell
- Laboratorio Nacional de Ciencias de la Sostenibilidad Instituto de Ecología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
| | - Cecilia Martínez‐Pérez
- Instituto de Biología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
| | - Calixto León‐Gómez
- Instituto de Biología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
| | - Alex Fajardo
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP) Camino Baguales s/n Coyhaique 5951601 Chile
| | - Sandrine Isnard
- Botanique et Modélisation de l’Architecture de Plantes de des Végétations Institut de Recherche pourle Développement Centre de Coopération Internationale en Recherche Agronomique pour le Développement Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique Université de Montpellier Montpellier 34398 France
- Botanique et Modélisation de l’Architecture de Plantes de des Végétations Institut de Recherche pourle Développement Herbier de Nouvelle‐Caledonia Nouméa 98848 New Caledonia
| | - María Angélica Cervantes‐Alcayde
- Instituto de Biología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
| | - Alberto Echeverría
- Instituto de Biología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
| | - Víctor A. Figueroa‐Abundiz
- Instituto de Biología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
| | - Alí Segovia‐Rivas
- Instituto de Biología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
| | - Santiago Trueba
- Botanique et Modélisation de l’Architecture de Plantes de des Végétations Institut de Recherche pourle Développement Centre de Coopération Internationale en Recherche Agronomique pour le Développement Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique Université de Montpellier Montpellier 34398 France
- Botanique et Modélisation de l’Architecture de Plantes de des Végétations Institut de Recherche pourle Développement Herbier de Nouvelle‐Caledonia Nouméa 98848 New Caledonia
- School of Forestry & Environmental Studies Yale University New Haven Connecticut 06511 USA
| | - Karen Vázquez‐Segovia
- Laboratorio Nacional de Ciencias de la Sostenibilidad Instituto de Ecología Universidad Nacional Autónoma de México Tercer Circuito s/n de Ciudad Universitaria Ciudad de México 04510 México
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17
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Zhang Y, Carmesin C, Kaack L, Klepsch MM, Kotowska M, Matei T, Schenk HJ, Weber M, Walther P, Schmidt V, Jansen S. High porosity with tiny pore constrictions and unbending pathways characterize the 3D structure of intervessel pit membranes in angiosperm xylem. PLANT, CELL & ENVIRONMENT 2020; 43:116-130. [PMID: 31595539 DOI: 10.1111/pce.13654] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 05/29/2023]
Abstract
Pit membranes between xylem vessels play a major role in angiosperm water transport. Yet, their three-dimensional (3D) structure as fibrous porous media remains unknown, largely due to technical challenges and sample preparation artefacts. Here, we applied a modelling approach based on thickness measurements of fresh and fully shrunken pit membranes of seven species. Pore constrictions were also investigated visually by perfusing fresh material with colloidal gold particles of known sizes. Based on a shrinkage model, fresh pit membranes showed tiny pore constrictions of ca. 20 nm, but a very high porosity (i.e. pore volume fraction) of on average 0.81. Perfusion experiments showed similar pore constrictions in fresh samples, well below 50 nm based on transmission electron microscopy. Drying caused a 50% shrinkage of pit membranes, resulting in much smaller pore constrictions. These findings suggest that pit membranes represent a mesoporous medium, with the pore space characterized by multiple constrictions. Constrictions are much smaller than previously assumed, but the pore volume is large and highly interconnected. Pores do not form highly tortuous, bent, or zigzagging pathways. These insights provide a novel view on pit membranes, which is essential to develop a mechanistic, 3D understanding of air-seeding through this porous medium.
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Affiliation(s)
- Ya Zhang
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- College of Life Sciences, Anhui Normal University, Beijingdong Road 1, 241000, Wuhu, Anhui, China
| | - Cora Carmesin
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Lucian Kaack
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Matthias M Klepsch
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Martyna Kotowska
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany
| | - Tabea Matei
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - H Jochen Schenk
- Department of Biological Science, California State University Fullerton, 800 N. State College Blvd, CA, 92831-3599, Fullerton, USA
| | - Matthias Weber
- Institute of Stochastics, Ulm University, Helmholtzstraße 18, 89069, Ulm, Germany
| | - Paul Walther
- Central Facility for Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Volker Schmidt
- Institute of Stochastics, Ulm University, Helmholtzstraße 18, 89069, Ulm, Germany
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
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18
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Wason JW, Brodersen CR, Huggett BA. The functional implications of tracheary connections across growth rings in four northern hardwood trees. ANNALS OF BOTANY 2019; 124:297-306. [PMID: 31330537 PMCID: PMC6758585 DOI: 10.1093/aob/mcz076] [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: 01/04/2019] [Accepted: 05/02/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Deciduous angiosperm trees transport xylem sap through trunks and branches in vessels within annual growth rings. Utilizing previous growth rings for sap transport could increase vessel network size and redundancy but may expose new xylem to residual air embolisms in the network. Despite the important role of vessel networks in sap transport and drought resistance, our understanding of cross-ring connections within and between species is limited. METHODS We studied cross-ring connections in four temperate deciduous trees using dye staining and X-ray microcomputed tomography (microCT) to detect xylem connectivity across growth rings and quantify their impact on hydraulic conductivity. KEY RESULTS Acer rubrum and Fraxinus americana had cross-ring connections visible in microCT but only A. rubrum used previous growth rings for axial sap flow. Fagus grandifolia and Quercus rubra, however, did not have cross-ring connections. Accounting for the number of growth rings that function for axial transport improved hydraulic conductivity estimates. CONCLUSIONS These data suggest that the presence of cross-ring connections may help explain aspects of whole-tree xylem sap transport and should be considered for plant hydraulics measurements in these species and others with similar anatomy.
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Affiliation(s)
- Jay W Wason
- School of Forest Resources, University of Maine, Orono, ME, USA
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
- For correspondence. E-mail
| | - Craig R Brodersen
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
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19
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Trueba S, Delzon S, Isnard S, Lens F. Similar hydraulic efficiency and safety across vesselless angiosperms and vessel-bearing species with scalariform perforation plates. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3227-3240. [PMID: 30921455 DOI: 10.1093/jxb/erz133] [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: 09/28/2018] [Accepted: 03/14/2019] [Indexed: 06/09/2023]
Abstract
The evolution of xylem vessels from tracheids is put forward as a key innovation that boosted hydraulic conductivity and photosynthetic capacities in angiosperms. Yet, the role of xylem anatomy and interconduit pits in hydraulic performance across vesselless and vessel-bearing angiosperms is incompletely known, and there is a lack of functional comparisons of ultrastructural pits between species with different conduit types. We assessed xylem hydraulic conductivity and vulnerability to drought-induced embolism in 12 rain forest species from New Caledonia, including five vesselless species, and seven vessel-bearing species with scalariform perforation plates. We measured xylem conduit traits, along with ultrastructural features of the interconduit pits, to assess the relationships between conduit traits and hydraulic efficiency and safety. In spite of major differences in conduit diameter, conduit density, and the presence/absence of perforation plates, the species studied showed similar hydraulic conductivity and vulnerability to drought-induced embolism, indicating functional similarity between both types of conduits. Interconduit pit membrane thickness (Tm) was the only measured anatomical feature that showed a relationship to significant vulnerability to embolism. Our results suggest that the incidence of drought in rain forest ecosystems can have similar effects on species bearing water-conducting cells with different morphologies.
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Affiliation(s)
- Santiago Trueba
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Charles E. Young Dr. South, Los Angeles, CA, USA
- AMAP, IRD, CIRAD, CNRS, INRA, Université de Montpellier, Nouméa, New Caledonia
| | | | - Sandrine Isnard
- AMAP, IRD, CIRAD, CNRS, INRA, Université de Montpellier, Nouméa, New Caledonia
| | - Frederic Lens
- Naturalis Biodiversity Center, Leiden University, Leiden, The Netherlands
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20
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Copini P, Vergeldt FJ, Fonti P, Sass-Klaassen U, den Ouden J, Sterck F, Decuyper M, Gerkema E, Windt CW, Van As H. Magnetic resonance imaging suggests functional role of previous year vessels and fibres in ring-porous sap flow resumption. TREE PHYSIOLOGY 2019; 39:1009-1018. [PMID: 30896019 DOI: 10.1093/treephys/tpz019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 01/15/2019] [Indexed: 06/09/2023]
Abstract
Reactivation of axial water flow in ring-porous species is a complex process related to stem water content and developmental stage of both earlywood-vessel and leaf formation. Yet empirical evidence with non-destructive methods on the dynamics of water flow resumption in relation to these mechanisms is lacking. Here we combined in vivo magnetic resonance imaging and wood-anatomical observations to monitor the dynamic changes in stem water content and flow during spring reactivation in 4-year-old pedunculate oaks (Quercus robur L.) saplings. We found that previous year latewood vessels and current year developing earlywood vessels form a functional unit for water flow during growth resumption. During spring reactivation, water flow shifted from latewood towards the new earlywood, paralleling the formation of earlywood vessels and leaves. At leaves' full expansion, volumetric water content of previous rings drastically decreased due to the near-absence of water in fibre tissue. We conclude (i) that in ring-porous oak, latewood vessels play an important hydraulic role for bridging the transition between old and new water-conducting vessels and (ii) that fibre and parenchyma provides a place for water storage.
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Affiliation(s)
- Paul Copini
- Forest Ecology and Forest Management Group, Wageningen University & Research, PO Box 47, AA Wageningen, The Netherlands
- Wageningen Environmental Research, Wageningen University & Research, PO Box 47, AA Wageningen, The Netherlands
| | - Frank J Vergeldt
- Laboratory of Biophysics and MAGNetic resonance research FacilitY (MAGNEFY), Wageningen University & Research, Postbus 8128, 6700ET Wageningen, The Netherlands
| | - Patrick Fonti
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland
| | - Ute Sass-Klaassen
- Forest Ecology and Forest Management Group, Wageningen University & Research, PO Box 47, AA Wageningen, The Netherlands
| | - Jan den Ouden
- Forest Ecology and Forest Management Group, Wageningen University & Research, PO Box 47, AA Wageningen, The Netherlands
| | - Frank Sterck
- Forest Ecology and Forest Management Group, Wageningen University & Research, PO Box 47, AA Wageningen, The Netherlands
| | - Mathieu Decuyper
- Forest Ecology and Forest Management Group, Wageningen University & Research, PO Box 47, AA Wageningen, The Netherlands
- Laboratory of Geo-Information Science and Remote Sensing, Wageningen University & Research, PO Box 47, AA Wageningen, The Netherlands
| | - Edo Gerkema
- Laboratory of Biophysics and MAGNetic resonance research FacilitY (MAGNEFY), Wageningen University & Research, Postbus 8128, 6700ET Wageningen, The Netherlands
| | - Carel W Windt
- IBG-2: Plant Sciences, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Henk Van As
- Laboratory of Biophysics and MAGNetic resonance research FacilitY (MAGNEFY), Wageningen University & Research, Postbus 8128, 6700ET Wageningen, The Netherlands
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21
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Pan R, Tyree MT. How does water flow from vessel to vessel? Further investigation of the tracheid bridge concept. TREE PHYSIOLOGY 2019; 39:1019-1031. [PMID: 30825311 DOI: 10.1093/treephys/tpz015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 01/22/2019] [Indexed: 06/09/2023]
Abstract
Hydraulic safety and efficiency have become the central concept of the interpretation of the structure and function of vessels and their interconnections. Plants form an appropriate xylem network structure to maintain a balance of hydraulic safety vs efficiency. The term 'tracheid bridge' is used to describe a possible pathway of water transport between neighboring vessels via tracheids, and this pathway could also provide increased safety against embolisms. However, the only physiological study of such a structure thus far has been in Hippophae rhamnoides Linn. To test the function of tracheid bridges, this research examined four species that have relatively long and solitary vessels, which are two of the criteria for efficient tracheid bridges. Tracheids contributed less than 2.2% of the total conductance of the vessels in these species, but in theory, tracheids could serve as very efficient transport connector pathways that may or may not make direct vessel-to-vessel contact via pit fields between adjacent vessels. In some species, tracheid bridges may represent the dominant pathway for water flow between vessels, whereas in other species, tracheid bridges may be sub-dominant or virtually nil. Broader searches of woody taxa are needed to reveal the functional importance of tracheid bridges in vascular plants.
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Affiliation(s)
- Ruihua Pan
- Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau & Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Melvin T Tyree
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, China
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22
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Pereira L, Flores-Borges DNA, Bittencourt PRL, Mayer JLS, Kiyota E, Araújo P, Jansen S, Freitas RO, Oliveira RS, Mazzafera P. Infrared Nanospectroscopy Reveals the Chemical Nature of Pit Membranes in Water-Conducting Cells of the Plant Xylem. PLANT PHYSIOLOGY 2018; 177:1629-1638. [PMID: 29871981 PMCID: PMC6084671 DOI: 10.1104/pp.18.00138] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/24/2018] [Indexed: 05/02/2023]
Abstract
In the xylem of angiosperm plants, microscopic pits through the secondary cell walls connect the water-conducting vessels. Cellulosic meshes originated from primary walls, and middle lamella between adjacent vessels, called the pit membrane, separates one conduit from another. The intricate structure of the nano-sized pores in pit membranes enables the passage of water under negative pressure without hydraulic failure due to obstruction by gas bubbles (i.e. embolism) under normal conditions or mild drought stress. Since the chemical composition of pit membranes affects embolism formation and bubble behavior, we directly measured pit membrane composition in Populus nigra wood. Here, we characterized the chemical composition of cell wall structures by synchrotron infrared nanospectroscopy and atomic force microscopy-infrared nanospectroscopy with high spatial resolution. Characteristic peaks of cellulose, phenolic compounds, and proteins were found in the intervessel pit membranes of P. nigra wood. In addition, the vessel to parenchyma pit membranes and developing cell walls of the vascular cambium showed clear signals of cellulose, proteins, and pectin. We did not find a distinct peak of lignin and other compounds in these structures. Our investigation of the complex chemical composition of intervessel pit membranes furthers our understanding of the flow of water and bubbles between neighboring conduits. The advances presented here pave the way for further label-free studies related to the nanochemistry of plant cell components.
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Affiliation(s)
- Luciano Pereira
- Department of Plant Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, Sao Paulo, Brazil
| | - Denisele N A Flores-Borges
- Department of Plant Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, Sao Paulo, Brazil
| | - Paulo R L Bittencourt
- Department of Plant Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, Sao Paulo, Brazil
| | - Juliana L S Mayer
- Department of Plant Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, Sao Paulo, Brazil
| | - Eduardo Kiyota
- Department of Plant Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, Sao Paulo, Brazil
| | - Pedro Araújo
- Department of Plant Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, Sao Paulo, Brazil
| | - Steven Jansen
- Ulm University, Institute of Systematic Botany and Ecology, 89081 Ulm, Germany
| | - Raul O Freitas
- Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, 13083-970 Campinas, Sao Paulo, Brazil
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, Sao Paulo, Brazil
| | - Paulo Mazzafera
- Department of Plant Biology, Institute of Biology, University of Campinas, 13083-970 Campinas, Sao Paulo, Brazil
- Department of Crop Production, School of Agriculture Luiz de Queiroz, University of São Paulo, 13418-900 Piracicaba, Sao Paulo, Brazil
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23
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Zhang Y, Lamarque LJ, Torres-Ruiz JM, Schuldt B, Karimi Z, Li S, Qin DW, Bittencourt P, Burlett R, Cao KF, Delzon S, Oliveira R, Pereira L, Jansen S. Testing the plant pneumatic method to estimate xylem embolism resistance in stems of temperate trees. TREE PHYSIOLOGY 2018; 38:1016-1025. [PMID: 29474679 PMCID: PMC6025199 DOI: 10.1093/treephys/tpy015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/19/2018] [Accepted: 01/31/2018] [Indexed: 05/23/2023]
Abstract
Methods to estimate xylem embolism resistance generally rely on hydraulic measurements, which can be far from straightforward. Recently, a pneumatic method based on air flow measurements of terminal branch ends was proposed to construct vulnerability curves by linking the amount of air extracted from a branch with the degree of embolism. We applied this novel technique for 10 temperate tree species, including six diffuse, two ring-porous and two gymnosperm species, and compared the pneumatic curves with hydraulic ones obtained from either the flow-centrifuge or the hydraulic-bench dehydration method. We found that the pneumatic method provides a good estimate of the degree of xylem embolism for all angiosperm species. The xylem pressure at 50% and 88% loss of hydraulic conductivity (i.e., Ψ50 and Ψ88) based on the methods applied showed a strongly significant correlation for all eight angiosperms. However, the pneumatic method showed significantly reduced Ψ50 values for the two conifers. Our findings suggest that the pneumatic method could provide a fast and accurate approach for angiosperms due to its convenience and feasibility, at least within the range of embolism resistances covered by our samples.
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Affiliation(s)
- Ya Zhang
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
| | - Laurent J Lamarque
- BIOGECO, INRA, University of Bordeaux, Pessac, France
- EGFV, INRA, University of Bordeaux, Villenave d’Ornon, France
| | | | - Bernhard Schuldt
- Albrecht-von-Haller-Institute for Plant Sciences, Göttingen University, Göttingen, Germany
| | - Zohreh Karimi
- Department of Biology, Faculty of Science, Golestan University, Gorgan, Iran
| | - Shan Li
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
- Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, PR China
| | - De-Wen Qin
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, PR China
| | - Paulo Bittencourt
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas – UNICAMP, Campinas, SP, Brazil
| | - Régis Burlett
- BIOGECO, INRA, University of Bordeaux, Pessac, France
| | - Kun-Fang Cao
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, PR China
| | | | - Rafael Oliveira
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas – UNICAMP, Campinas, SP, Brazil
| | - Luciano Pereira
- Department of Plant Biology, Institute of Biology, PO Box 6109, University of Campinas – UNICAMP, Campinas, SP, Brazil
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
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24
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Zhang Y, Klepsch M, Jansen S. Bordered pits in xylem of vesselless angiosperms and their possible misinterpretation as perforation plates. PLANT, CELL & ENVIRONMENT 2017; 40:2133-2146. [PMID: 28667823 DOI: 10.1111/pce.13014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 06/27/2017] [Indexed: 06/07/2023]
Abstract
Vesselless wood represents a rare phenomenon within the angiosperms, characterizing Amborellaceae, Trochodendraceae and Winteraceae. Anatomical observations of bordered pits and their pit membranes based on light, scanning and transmission electron microscopy (SEM and TEM) are required to understand functional questions surrounding vesselless angiosperms and the potential occurrence of cryptic vessels. Interconduit pit membranes in 11 vesselless species showed a similar ultrastructure as mesophytic vessel-bearing angiosperms, with a mean thickness of 245 nm (± 53, SD; n = six species). Shrunken, damaged and aspirated pit membranes, which were 52% thinner than pit membranes in fresh samples (n = four species), occurred in all dried-and-rehydrated samples, and in fresh latewood of Tetracentron sinense and Trochodendron aralioides. SEM demonstrated that shrunken pit membranes showed artificially enlarged, > 100 nm wide pores. Moreover, perfusion experiments with stem segments of Drimys winteri showed that 20 and 50 nm colloidal gold particles only passed through 2 cm long dried-and-rehydrated segments, but not through similar sized fresh ones. These results indicate that pit membrane shrinkage is irreversible and associated with a considerable increase in pore size. Moreover, our findings suggest that pit membrane damage, which may occur in planta, could explain earlier records of vessels in vesselless angiosperms.
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Affiliation(s)
- Ya Zhang
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Matthias Klepsch
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
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25
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Jura-Morawiec J. Atypical origin, structure and arrangement of secondary tracheary elements in the stem of the monocotyledonous dragon tree, Dracaena draco. PLANTA 2017; 245:93-99. [PMID: 27585974 PMCID: PMC5226991 DOI: 10.1007/s00425-016-2593-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 08/25/2016] [Indexed: 06/06/2023]
Abstract
Tracheary elements within the secondary body of a dragon tree shared features characteristic of fibres. Their considerable intrusive growth resulted in a rigid network with a braid-like arrangement which contributes towards the tree-like form of the plant. Monocot cambium gives rise to xylem and phloem which become organized into vascular bundles. The xylem consists entirely of tracheids, and these undergo considerable intrusive elongation during their development, unlike the tracheids of conifers and those of vesselless dicotyledons. Monocot tracheids have not been fully investigated, and our understanding of their structure is incomplete. Therefore, in this study the degree of variation in the structure and arrangement of secondary tracheary elements of monocots were determined, based on the Dracaena draco stem. In addition, its mechanical and physiological implications were discussed. Analysis of series of thin serial sections and macerations of the immature and fully developed tracheids showed that the course of intrusive elongation of tracheids was determined by the spatial relationship that exists between the growing tracheid and surrounding cells, and was not usually parallel to the stem axis. It influenced the shape of tracheids, as well the cross-sectional shape of vascular bundles. Tracheids become twisted or even interwoven and so, their ends do not join with the ends of other tracheids. The complexity of the tracheid network, that functions both in transport and mechanical support, seems to have a major impact on the tree-like growth habit of D. draco.
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Affiliation(s)
- Joanna Jura-Morawiec
- Polish Academy of Sciences Botanical Garden, Centre for Biological Diversity Conservation in Powsin, Prawdziwka 2, 02-973, Warsaw, Poland.
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26
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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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27
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Nakaba S, Yamane K, Fukahori M, Nugroho WD, Yamaguchi M, Kuroda K, Sano Y, Wuled Lenggoro I, Izuta T, Funada R. Effect of epicuticular wax crystals on the localization of artificially deposited sub-micron carbon-based aerosols on needles of Cryptomeria japonica. JOURNAL OF PLANT RESEARCH 2016; 129:873-881. [PMID: 27294967 DOI: 10.1007/s10265-016-0839-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 04/17/2016] [Indexed: 06/06/2023]
Abstract
Elucidation of the mechanism of adsorption of particles suspended in the gas-phase (aerosol) to the outer surfaces of leaves provides useful information for understanding the mechanisms of the effect of aerosol particles on the growth and physiological functions of trees. In the present study, we examined the localization of artificially deposited sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica, a typical Japanese coniferous tree species, by field-emission scanning electron microscopy. The clusters (aggregates) of carbon-based particles were deposited on the needle surface regions where epicuticular wax crystals were sparsely distributed. By contrast, no clusters of the particles were found on the needle surface regions with dense distribution of epicuticular wax crystals. Number of clusters of carbon-based particles per unit area showed statistically significant differences between regions with sparse epicuticular wax crystals and those with dense epicuticular wax crystals. These results suggest that epicuticular wax crystals affect distribution of carbon-based particles on needles. Therefore, densely distributed epicuticular wax crystals might prevent the deposition of sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica to retain the function of stomata.
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Affiliation(s)
- Satoshi Nakaba
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| | - Kenichi Yamane
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| | - Mie Fukahori
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| | - Widyanto Dwi Nugroho
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
- Faculty of Forestry, Universitas Gadjah Mada, Jalan Agro No. 1 Bulaksumur, Yogyakarta, 55281, Indonesia
| | - Masahiro Yamaguchi
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, Nagasaki, 852-8521, Japan
| | - Katsushi Kuroda
- Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki, 305-8687, Japan
| | - Yuzou Sano
- Graduate School of Agriculture, Hokkaido University, Kita 9, Nishi 9, Kita-ku, Sapporo, Hokkaido, 060-8589, Japan
| | - I Wuled Lenggoro
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Takeshi Izuta
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| | - Ryo Funada
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan.
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28
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Jupa R, Plavcová L, Gloser V, Jansen S. Linking xylem water storage with anatomical parameters in five temperate tree species. TREE PHYSIOLOGY 2016; 36:756-69. [PMID: 27083523 DOI: 10.1093/treephys/tpw020] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 02/28/2016] [Indexed: 05/26/2023]
Abstract
The release of water from storage compartments to the transpiration stream is an important functional mechanism that provides the buffering of sudden fluctuations in water potential. The ability of tissues to release water per change in water potential, referred to as hydraulic capacitance, is assumed to be associated with the anatomy of storage tissues. However, information about how specific anatomical parameters determine capacitance is limited. In this study, we measured sapwood capacitance (C) in terminal branches and roots of five temperate tree species (Fagus sylvatica L., Picea abies L., Quercus robur L., Robinia pseudoacacia L., Tilia cordata Mill.). Capacitance was calculated separately for water released mainly from capillary (CI; open vessels, tracheids, fibres, intercellular spaces and cracks) and elastic storage compartments (CII; living parenchyma cells), corresponding to two distinct phases of the moisture release curve. We found that C was generally higher in roots than branches, with CI being 3-11 times higher than CII Sapwood density and the ratio of dead to living xylem cells were most closely correlated with C In addition, the magnitude of CI was strongly correlated with fibre/tracheid lumen area, whereas CII was highly dependent on the thickness of axial parenchyma cell walls. Our results indicate that water released from capillary compartments predominates over water released from elastic storage in both branches and roots, suggesting the limited importance of parenchyma cells for water storage in juvenile xylem of temperate tree species. Contrary to intact organs, water released from open conduits in our small wood samples significantly increased CI at relatively high water potentials. Linking anatomical parameters with the hydraulic capacitance of a tissue contributes to a better understanding of water release mechanisms and their implications for plant hydraulics.
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Affiliation(s)
- Radek Jupa
- Faculty of Science, Department of Experimental Biology, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Lenka Plavcová
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 890 81 Ulm, Germany Faculty of Science, Department of Experimental Plant Biology, Charles University, Viničná 5, 128 44 Prague, Czech Republic
| | - Vít Gloser
- Faculty of Science, Department of Experimental Biology, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 890 81 Ulm, Germany
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29
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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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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: 12] [Impact Index Per Article: 1.3] [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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31
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Graf I, Ceseri M, Stockie JM. Multiscale model of a freeze-thaw process for tree sap exudation. J R Soc Interface 2015; 12:20150665. [PMID: 26400199 PMCID: PMC4614504 DOI: 10.1098/rsif.2015.0665] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 08/28/2015] [Indexed: 11/12/2022] Open
Abstract
Sap transport in trees has long fascinated scientists, and a vast literature exists on experimental and modelling studies of trees during the growing season when large negative stem pressures are generated by transpiration from leaves. Much less attention has been paid to winter months when trees are largely dormant but nonetheless continue to exhibit interesting flow behaviour. A prime example is sap exudation, which refers to the peculiar ability of sugar maple (Acer saccharum) and related species to generate positive stem pressure while in a leafless state. Experiments demonstrate that ambient temperatures must oscillate about the freezing point before significantly heightened stem pressures are observed, but the precise causes of exudation remain unresolved. The prevailing hypothesis attributes exudation to a physical process combining freeze-thaw and osmosis, which has some support from experimental studies but remains a subject of active debate. We address this knowledge gap by developing the first mathematical model for exudation, while also introducing several essential modifications to this hypothesis. We derive a multiscale model consisting of a nonlinear system of differential equations governing phase change and transport within wood cells, coupled to a suitably homogenized equation for temperature on the macroscale. Numerical simulations yield stem pressures that are consistent with experiments and provide convincing evidence that a purely physical mechanism is capable of capturing exudation.
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Affiliation(s)
- Isabell Graf
- Department of Mathematics, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6
| | - Maurizio Ceseri
- Consiglio Nazionale delle Ricerche, Istituto per le Applicazioni del Calcolo 'Mauro Picone', via dei Taurini 19, Rome 00185, Italy
| | - John M Stockie
- Department of Mathematics, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6
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Cai J, Li S, Zhang H, Zhang S, Tyree MT. Recalcitrant vulnerability curves: methods of analysis and the concept of fibre bridges for enhanced cavitation resistance. PLANT, CELL & ENVIRONMENT 2014; 37:35-44. [PMID: 23600520 DOI: 10.1111/pce.12120] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 04/05/2013] [Accepted: 04/09/2013] [Indexed: 05/26/2023]
Abstract
Vulnerability curves (VCs) generally can be fitted to the Weibull equation; however, a growing number of VCs appear to be recalcitrant, that is, deviate from a Weibull but seem to fit dual Weibull curves. We hypothesize that dual Weibull curves in Hippophae rhamnoides L. are due to different vessel diameter classes, inter-vessel hydraulic connections or vessels versus fibre tracheids. We used dye staining techniques, hydraulic measurements and quantitative anatomy measurements to test these hypotheses. The fibres contribute 1.3% of the total stem conductivity, which eliminates the hypothesis that fibre tracheids account for the second Weibull curve. Nevertheless, the staining pattern of vessels and fibre tracheids suggested that fibres might function as a hydraulic bridge between adjacent vessels. We also argue that fibre bridges are safer than vessel-to-vessel pits and put forward the concept as a new paradigm. Hence, we tentatively propose that the first Weibull curve may be accounted by vessels connected to each other directly by pit fields, while the second Weibull curve is associated with vessels that are connected almost exclusively by fibre bridges. Further research is needed to test the concept of fibre bridge safety in species that have recalcitrant or normal Weibull curves.
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Affiliation(s)
- Jing Cai
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China; Qinling National Forest Ecosystem Research Station, Yangling, Shaanxi, 712100, China
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Cochard H, Badel E, Herbette S, Delzon S, Choat B, Jansen S. Methods for measuring plant vulnerability to cavitation: a critical review. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:4779-91. [PMID: 23888067 DOI: 10.1093/jxb/ert193] [Citation(s) in RCA: 205] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Xylem cavitation resistance has profound implications for plant physiology and ecology. This process is characterized by a 'vulnerability curve' (VC) showing the variation of the percentage of cavitation as a function of xylem pressure potential. The shape of this VC varies from 'sigmoidal' to 'exponential'. This review provides a panorama of the techniques that have been used to generate such a curve. The techniques differ by (i) the way cavitation is induced (e.g. bench dehydration, centrifugation, or air injection), and (ii) the way cavitation is measured (e.g. percentage loss of conductivity (PLC) or acoustic emission), and a nomenclature is proposed based on these two methods. A survey of the literature of more than 1200 VCs was used to draw statistics on the usage of these methods and on their reliability and validity. Four methods accounted for more than 96% of all curves produced so far: bench dehydration-PLC, centrifugation-PLC, pressure sleeve-PLC, and Cavitron. How the shape of VCs varies across techniques and species xylem anatomy was also analysed. Strikingly, it was found that the vast majority of curves obtained with the reference bench dehydration-PLC method are 'sigmoidal'. 'Exponential' curves were more typical of the three other methods and were remarkably frequent for species having large xylem conduits (ring-porous), leading to a substantial overestimation of the vulnerability of cavitation for this functional group. We suspect that 'exponential' curves may reflect an open-vessel artefact and call for more precautions with the usage of the pressure sleeve and centrifugation techniques.
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Affiliation(s)
- Hervé Cochard
- INRA, UMR 547 PIAF, F-63100 Clermont-Ferrand, France
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34
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Ziemińska K, Butler DW, Gleason SM, Wright IJ, Westoby M. Fibre wall and lumen fractions drive wood density variation across 24 Australian angiosperms. AOB PLANTS 2013; 5:plt046. [PMCID: PMC4104653 DOI: 10.1093/aobpla/plt046] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Wood density is often considered to be a key plant functional trait. But it is not clear what actually wood density is? We rigorously quantified anatomical underpinnings of wood density variation. We found that density was mainly driven by properties of mechanical tissue such as fibre wall fraction and fibre lumen fraction. However, there was also a substantial anatomical variation independent of density. This variation suggests that different plant ecological strategies may be available to woods with the same density. Our results imply that density is a complex characteristic of wood rather than a straightforward indicator of plant ecological strategies. Wood density is considered a key plant trait, affecting mechanical and physiological performance, yet its biological meaning is still rather unclear. Accordingly we investigated the anatomical underpinnings of wood density in trees and shrubs. We measured wood density and anatomical traits in distal stems 4–10 mm diameter under bark in 24 Australian species. Proportions of wood components that are functionally distinct were analysed, including fibre wall and lumen, vessel wall and lumen, and axial and ray parenchyma. Wood density was mainly driven by the density of wood outside vessel lumens (densityNV) rather than by vessel lumen fraction. In turn, densityNV variation was chiefly affected by fibre wall and lumen fractions. Considerable anatomical variation was observed at a given densityNV, especially among medium-densityNV species (0.60–0.85 g cm−3); this range of medium densityNV roughly translates to 0.50–0.75 g cm−3 of overall density. The anatomy of these species formed a continuum from low fibre lumen and medium parenchyma fractions to medium fibre lumen and low parenchyma fractions. Our data suggest that wood density is an emergent property influenced by a complex anatomy rather than an unambiguous functional trait, particularly in medium-density species. With much anatomical variation, they likely represent a wide range of ecological strategies.
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Affiliation(s)
- Kasia Ziemińska
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
- Corresponding author's e-mail address:
| | - Don W. Butler
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
- Present address: Queensland Herbarium, Mt Coot-tha Road, Toowong, QLD 4066, Australia
| | - Sean M. Gleason
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Ian J. Wright
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Mark Westoby
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
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Scholz A, Rabaey D, Stein A, Cochard H, Smets E, Jansen S. The evolution and function of vessel and pit characters with respect to cavitation resistance across 10 Prunus species. TREE PHYSIOLOGY 2013; 33:684-694. [PMID: 23933827 DOI: 10.1093/treephys/tpt050] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Various structure-function relationships regarding drought-induced cavitation resistance of secondary xylem have been postulated. These hypotheses were tested on wood of 10 Prunus species showing a range in P50 (i.e., the pressure corresponding to 50% loss of hydraulic conductivity) from -3.54 to -6.27 MPa. Hydraulically relevant wood characters were quantified using light and electron microscopy. A phylogenetic tree was constructed to investigate evolutionary correlations using a phylogenetically independent contrast (PIC) analysis. Vessel-grouping characters were found to be most informative in explaining interspecific variation in P50, with cavitation-resistant species showing more solitary vessels than less resistant species. Co-evolution between vessel-grouping indices and P50 was reported. P50 was weakly correlated with the shape of the intervessel pit aperture, but not with the total intervessel pit membrane area per vessel. A negative correlation was found between P50 and intervessel pit membrane thickness, but this relationship was not supported by the PIC analysis. Cavitation resistance has co-evolved with vessel grouping within Prunus and was mainly influenced by the spatial distribution of the vessel network.
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Affiliation(s)
- Alexander Scholz
- Institute for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany
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36
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Tixier A, Cochard H, Badel E, Dusotoit-Coucaud A, Jansen S, Herbette S. Arabidopsis thaliana as a model species for xylem hydraulics: does size matter? JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:2295-305. [PMID: 23547109 PMCID: PMC3654419 DOI: 10.1093/jxb/ert087] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
While Arabidopsis thaliana has been proposed as a model species for wood development, the potential of this tiny herb for studying xylem hydraulics remains unexplored and anticipated by scepticism. Inflorescence stems of A. thaliana were used to measure hydraulic conductivity and cavitation resistance, whereas light and electron microscopy allowed observations of vessels. In wild-type plants, measured and theoretical conductivity showed a significant correlation (R (2) = 0.80, P < 0.01). Moreover, scaling of vessel dimensions and intervessel pit structure of A. thaliana were consistent with structure-function relationships of woody plants. The reliability and resolution of the hydraulic methods applied to measure vulnerability to cavitation were addressed by comparing plants grown under different photoperiods or different mutant lines. Sigmoid vulnerability curves of A. thaliana indicated a pressure corresponding to 50% loss of hydraulic conductance (P 50) between -3 and -2.5MPa for short-day and long-day plants, respectively. Polygalacturonase mutants showed a higher P 50 value (-2.25MPa), suggesting a role for pectins in vulnerability to cavitation. The application of A. thaliana as a model species for xylem hydraulics provides exciting possibilities for (1) exploring the molecular basis of xylem anatomical features and (2) understanding genetic mechanisms behind xylem functional traits such as cavitation resistance. Compared to perennial woody species, however, the lesser amount of xylem in A. thaliana has its limitations.
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Affiliation(s)
- Aude Tixier
- Clermont Université, Université Blaise Pascal, UMR 547 PIAF, F-63177, Aubière, France
- Institute for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, D–89081, Ulm, Germany
| | - Hervé Cochard
- INRA, UMR 547 PIAF, F-63100 Clermont-Ferrand, France
| | - Eric Badel
- INRA, UMR 547 PIAF, F-63100 Clermont-Ferrand, France
| | | | - Steven Jansen
- Institute for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, D–89081, Ulm, Germany
| | - Stéphane Herbette
- Clermont Université, Université Blaise Pascal, UMR 547 PIAF, F-63177, Aubière, France
- * To whom correspondence should be addressed. E-mail:
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Scholz A, Klepsch M, Karimi Z, Jansen S. How to quantify conduits in wood? FRONTIERS IN PLANT SCIENCE 2013; 4:56. [PMID: 23507674 PMCID: PMC3600434 DOI: 10.3389/fpls.2013.00056] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 02/28/2013] [Indexed: 05/02/2023]
Abstract
Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology.
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Affiliation(s)
- Alexander Scholz
- Institute for Systematic Botany and Ecology, Ulm UniversityUlm, Germany
| | - Matthias Klepsch
- Institute for Systematic Botany and Ecology, Ulm UniversityUlm, Germany
| | - Zohreh Karimi
- Institute for Systematic Botany and Ecology, Ulm UniversityUlm, Germany
- Golestan UniversityGorgan, Iran
| | - Steven Jansen
- Institute for Systematic Botany and Ecology, Ulm UniversityUlm, Germany
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Plavcová L, Jansen S, Klepsch M, Hacke UG. Nobody's perfect: can irregularities in pit structure influence vulnerability to cavitation? FRONTIERS IN PLANT SCIENCE 2013; 4:453. [PMID: 24273549 PMCID: PMC3824106 DOI: 10.3389/fpls.2013.00453] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 10/22/2013] [Indexed: 05/04/2023]
Abstract
Recent studies have suggested that species-specific pit properties such as pit membrane thickness, pit membrane porosity, torus-to-aperture diameter ratio and pit chamber depth influence xylem vulnerability to cavitation. Despite the indisputable importance of using mean pit characteristics, considerable variability in pit structure within a single species or even within a single pit field should be acknowledged. According to the rare pit hypothesis, a single pit that is more air-permeable than many neighboring pits is sufficient to allow air-seeding. Therefore, any irregularities or morphological abnormalities in pit structure allowing air-seeding should be associated with increased vulnerability to cavitation. Considering the currently proposed models of air-seeding, pit features such as rare, large pores in the pit membrane, torus extensions, and plasmodesmatal pores in a torus can represent potential glitches. These aberrations in pit structure could either result from inherent developmental flaws, or from damage caused to the pit membrane by chemical and physical agents. This suggests the existence of interesting feedbacks between abiotic and biotic stresses in xylem physiology.
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Affiliation(s)
- Lenka Plavcová
- Institute for Systematic Botany and Ecology, Ulm UniversityUlm, Germany
- *Correspondence: Lenka Plavcová, Institute for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany e-mail:
| | - Steven Jansen
- Institute for Systematic Botany and Ecology, Ulm UniversityUlm, Germany
| | - Matthias Klepsch
- Institute for Systematic Botany and Ecology, Ulm UniversityUlm, Germany
| | - Uwe G. Hacke
- Department of Renewable Resources, University of AlbertaEdmonton, AB, Canada
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