1
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Ziegler C, Cochard H, Stahl C, Foltzer L, Gérard B, Goret JY, Heuret P, Levionnois S, Maillard P, Bonal D, Coste S. Residual water losses mediate the trade-off between growth and drought survival across saplings of 12 tropical rainforest tree species with contrasting hydraulic strategies. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4128-4147. [PMID: 38613495 DOI: 10.1093/jxb/erae159] [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: 07/31/2023] [Accepted: 04/12/2024] [Indexed: 04/15/2024]
Abstract
Knowledge of the physiological mechanisms underlying species vulnerability to drought is critical for better understanding patterns of tree mortality. Investigating plant adaptive strategies to drought should thus help to fill this knowledge gap, especially in tropical rainforests exhibiting high functional diversity. In a semi-controlled drought experiment using 12 rainforest tree species, we investigated the diversity in hydraulic strategies and whether they determined the ability of saplings to use stored non-structural carbohydrates during an extreme imposed drought. We further explored the importance of water- and carbon-use strategies in relation to drought survival through a modelling approach. Hydraulic strategies varied considerably across species with a continuum between dehydration tolerance and avoidance. During dehydration leading to hydraulic failure and irrespective of hydraulic strategies, species showed strong declines in whole-plant starch concentrations and maintenance, or even increases in soluble sugar concentrations, potentially favouring osmotic adjustments. Residual water losses mediated the trade-off between time to hydraulic failure and growth, indicating that dehydration avoidance is an effective drought-survival strategy linked to the 'fast-slow' continuum of plant performance at the sapling stage. Further investigations on residual water losses may be key to understanding the response of tropical rainforest tree communities to climate change.
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Affiliation(s)
- Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Hervé Cochard
- Université Clermont-Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Louis Foltzer
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Bastien Gérard
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Jean-Yves Goret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
| | - Patrick Heuret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD, 34000 Montpellier, France
| | - Sébastien Levionnois
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
- AMAP, Univ. Montpellier, CIRAD, CNRS, INRAE, IRD, 34000 Montpellier, France
| | - Pascale Maillard
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Damien Bonal
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, 54000 Nancy, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, 97310 Kourou, France
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2
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D'Amico L, Svetlove A, Longo E, Meyer R, Senigagliesi B, Saccomano G, Nolte P, Wagner WL, Wielpütz MO, Leitz DHW, Duerr J, Mall MA, Casalis L, Köster S, Alves F, Tromba G, Dullin C. Characterization of transient and progressive pulmonary fibrosis by spatially correlated phase contrast microCT, classical histopathology and atomic force microscopy. Comput Biol Med 2024; 169:107947. [PMID: 38211385 DOI: 10.1016/j.compbiomed.2024.107947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/07/2023] [Accepted: 01/01/2024] [Indexed: 01/13/2024]
Abstract
Pulmonary fibrosis (PF) is a severe and progressive condition in which the lung becomes scarred over time resulting in pulmonary function impairment. Classical histopathology remains an important tool for micro-structural tissue assessment in the diagnosis of PF. A novel workflow based on spatial correlated propagation-based phase-contrast micro computed tomography (PBI-microCT), atomic force microscopy (AFM) and histopathology was developed and applied to two different preclinical mouse models of PF - the commonly used and well characterized Bleomycin-induced PF and a novel mouse model for progressive PF caused by conditional Nedd4-2 KO. The aim was to integrate structural and mechanical features from hallmarks of fibrotic lung tissue remodeling. PBI-microCT was used to assess structural alteration in whole fixed and paraffin embedded lungs, allowing for identification of fibrotic foci within the 3D context of the entire organ and facilitating targeted microtome sectioning of planes of interest for subsequent histopathology. Subsequently, these sections of interest were subjected to AFM to assess changes in the local tissue stiffness of previously identified structures of interest. 3D whole organ analysis showed clear morphological differences in 3D tissue porosity between transient and progressive PF and control lungs. By integrating the results obtained from targeted AFM analysis, it was possible to discriminate between the Bleomycin model and the novel conditional Nedd4-2 KO model using agglomerative cluster analysis. As our workflow for 3D spatial correlation of PBI, targeted histopathology and subsequent AFM is tailored around the standard procedure of formalin-fixed paraffin-embedded (FFPE) tissue specimens, it may be a powerful tool for the comprehensive tissue assessment beyond the scope of PF and preclinical research.
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Affiliation(s)
- Lorenzo D'Amico
- University of Trieste, Department of Physics, Via Alfonso Valerio 2, Trieste, 34127, Italy; Elettra Sincrotrone Trieste S.C.p.A., s.s. 14 km 163, 500 in Area Science Park, Basovizza, 34149, Italy
| | - Angelika Svetlove
- Translational Molecular Imaging, Max-Plank-Institute for Multidisciplinary Sciences, Hermann-Rein-Straße 3, Göttingen, 37075, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Robert-Koch-Str. 40, Göttingen, 37075, Germany
| | - Elena Longo
- Elettra Sincrotrone Trieste S.C.p.A., s.s. 14 km 163, 500 in Area Science Park, Basovizza, 34149, Italy
| | - Ruth Meyer
- Institute for X-ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, Göttingen, 37077, Germany
| | - Beatrice Senigagliesi
- Interdisciplinary Institute for Neuroscience, University of Bordeaux-UMR 5297 and CNRS, 146 Rue Léo Saignat, Bordeaux, 33000, France
| | - Giulia Saccomano
- Elettra Sincrotrone Trieste S.C.p.A., s.s. 14 km 163, 500 in Area Science Park, Basovizza, 34149, Italy; University of Trieste, Department of Architecture and Engineering, Via Alfonso Valerio 6/1, Trieste, 34127, Italy
| | - Philipp Nolte
- Faculty of Engineering and Health, University of Applied Sciences and Arts, Göttingen, 37085, Germany; Institute for Diagnostic and Interventional Radiology, University Medical Center, Göttingen, 37075, Germany
| | - Willi L Wagner
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Mark O Wielpütz
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Dominik H W Leitz
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charite - University Hospital Berlin, Berlin, 13353, Germany; German Center for Lung Research (DZL), associated partner site, Berlin, Germany; Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, 10117, Germany
| | - Julia Duerr
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charite - University Hospital Berlin, Berlin, 13353, Germany; German Center for Lung Research (DZL), associated partner site, Berlin, Germany; Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, 10117, Germany
| | - Marcus A Mall
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charite - University Hospital Berlin, Berlin, 13353, Germany; German Center for Lung Research (DZL), associated partner site, Berlin, Germany; Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, 10117, Germany
| | - Loredana Casalis
- Elettra Sincrotrone Trieste S.C.p.A., s.s. 14 km 163, 500 in Area Science Park, Basovizza, 34149, Italy
| | - Sarah Köster
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Robert-Koch-Str. 40, Göttingen, 37075, Germany; Institute for X-ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, Göttingen, 37077, Germany
| | - Frauke Alves
- Translational Molecular Imaging, Max-Plank-Institute for Multidisciplinary Sciences, Hermann-Rein-Straße 3, Göttingen, 37075, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Robert-Koch-Str. 40, Göttingen, 37075, Germany; Institute for Diagnostic and Interventional Radiology, University Medical Center, Göttingen, 37075, Germany; Department for Haematology and Medical Oncology, University Medical Center, Göttingen, 37075, Germany
| | - Giuliana Tromba
- Elettra Sincrotrone Trieste S.C.p.A., s.s. 14 km 163, 500 in Area Science Park, Basovizza, 34149, Italy
| | - Christian Dullin
- Elettra Sincrotrone Trieste S.C.p.A., s.s. 14 km 163, 500 in Area Science Park, Basovizza, 34149, Italy; Translational Molecular Imaging, Max-Plank-Institute for Multidisciplinary Sciences, Hermann-Rein-Straße 3, Göttingen, 37075, Germany; Institute for Diagnostic and Interventional Radiology, University Medical Center, Göttingen, 37075, Germany; Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.
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3
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Liu J, Hochberg U, Ding R, Xiong D, Dai Z, Zhao Q, Chen J, Ji S, Kang S. Elevated CO2 concentration increases maize growth under water deficit or soil salinity but with a higher risk of hydraulic failure. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:422-437. [PMID: 37715996 DOI: 10.1093/jxb/erad365] [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: 04/26/2023] [Accepted: 09/15/2023] [Indexed: 09/18/2023]
Abstract
Climate change presents a challenge for plants to acclimate their water relations under changing environmental conditions, and may increase the risks of hydraulic failure under stress. In this study, maize plants were acclimated to two different CO2 concentrations ([CO2]; 400 ppm and 700 ppm) while under either water stress (WS) or soil salinity (SS) treatments, and their growth and hydraulic traits were examined in detail. Both WS and SS inhibited growth and had significant impacts on hydraulic traits. In particular, the water potential at 50% loss of stem hydraulic conductance (P50) decreased by 1 MPa in both treatments at 400 ppm. When subjected to elevated [CO2], the plants under both WS and SS showed improved growth by 7-23%. Elevated [CO2] also significantly increased xylem vulnerability (measured as loss of conductivity with decreasing xylem pressure), resulting in smaller hydraulic safety margins. According to the plant desiccation model, the critical desiccation degree (time×vapor pressure deficit) that the plants could tolerate under drought was reduced by 43-64% under elevated [CO2]. In addition, sensitivity analysis showed that P50 was the most important trait in determining the critical desiccation degree. Thus, our results demonstrated that whilst elevated [CO2] benefited plant growth under WS or SS, it also interfered with hydraulic acclimation, thereby potentially placing the plants at a higher risk of hydraulic failure and increased mortality.
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Affiliation(s)
- Junzhou Liu
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Uri Hochberg
- Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization Volcani Center, Bet Dagan, 7505101, Israel
| | - Risheng Ding
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Dongliang Xiong
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhanwu Dai
- Beijing Key Laboratory of Grape Science and Enology and Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China
| | - Qing Zhao
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Jinliang Chen
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Shasha Ji
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
| | - Shaozhong Kang
- Center for Agricultural Water Research in China, China Agricultural University, Beijing, 100083, China
- National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733009, China
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4
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Tomasella M, Petruzzellis F, Natale S, Tromba G, Nardini A. Detecting and Quantifying Xylem Embolism by Synchrotron-Based X-Ray Micro-CT. Methods Mol Biol 2024; 2722:51-63. [PMID: 37897599 DOI: 10.1007/978-1-0716-3477-6_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/30/2023]
Abstract
The vulnerability to xylem embolism is a key trait underlying species-specific drought tolerance of plants, and hence is critical for screening climate-resilient crops and understanding vegetation responses to drought and heat waves. Yet, accurate determination of embolism in plant's xylem is challenging, because most traditional hydraulic techniques are destructive and prone to artefacts. Hence, direct and in vivo synchrotron-based X-ray micro-CT observation of xylem conduits has emerged as a key reference technique for accurate quantification of vulnerability to xylem embolism. Micro-CT is nowadays a fundamental tool for studies of plant hydraulic architecture, and this chapter describes the fundamentals of acquisition and processing of micro-CT images of plant xylem.
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Affiliation(s)
- Martina Tomasella
- Dipartimento di Scienze della Vita, Università di Trieste, Trieste, Italy
| | | | - Sara Natale
- Dipartimento di Scienze della Vita, Università di Trieste, Trieste, Italy
| | | | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Trieste, Italy.
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5
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Isasa E, Link RM, Jansen S, Tezeh FR, Kaack L, Sarmento Cabral J, Schuldt B. Addressing controversies in the xylem embolism resistance-vessel diameter relationship. THE NEW PHYTOLOGIST 2023; 238:283-296. [PMID: 36636783 DOI: 10.1111/nph.18731] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Although xylem embolism is a key process during drought-induced tree mortality, its relationship to wood anatomy remains debated. While the functional link between bordered pits and embolism resistance is known, there is no direct, mechanistic explanation for the traditional assumption that wider vessels are more vulnerable than narrow ones. We used data from 20 temperate broad-leaved tree species to study the inter- and intraspecific relationship of water potential at 50% loss of conductivity (P50 ) with hydraulically weighted vessel diameter (Dh ) and tested its link to pit membrane thickness (TPM ) and specific conductivity (Ks ) on species level. Embolism-resistant species had thick pit membranes and narrow vessels. While Dh was weakly associated with TPM , the P50 -Dh relationship remained highly significant after accounting for TPM . The interspecific pattern between P50 and Dh was mirrored by a link between P50 and Ks , but there was no evidence for an intraspecific relationship. Our results provide robust evidence for an interspecific P50 -Dh relationship across our species. As a potential cause for the inconsistencies in published P50 -Dh relationships, our analysis suggests differences in the range of trait values covered, and the level of data aggregation (species, tree or sample level) studied.
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Affiliation(s)
- Emilie Isasa
- Ecophysiology and Vegetation Ecology, Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz 3, 97082, Würzburg, Germany
| | - Roman Mathias Link
- Ecophysiology and Vegetation Ecology, Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz 3, 97082, Würzburg, Germany
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technical University of Dresden, Pienner Str. 7, 01737, Tharandt, Germany
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Fon Robinson Tezeh
- Ecophysiology and Vegetation Ecology, Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz 3, 97082, Würzburg, Germany
| | - Lucian Kaack
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Juliano Sarmento Cabral
- Ecosystem Modeling Group, Center for Computational and Theoretical Biology, University of Würzburg, Klara-Oppenheimer-Weg 32, 97074, Würzburg, Germany
- Biodiversity Modelling and Environmental Change, School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Bernhard Schuldt
- Ecophysiology and Vegetation Ecology, Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz 3, 97082, Würzburg, Germany
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technical University of Dresden, Pienner Str. 7, 01737, Tharandt, Germany
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6
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Lens F, Gleason SM, Bortolami G, Brodersen C, Delzon S, Jansen S. Functional xylem characteristics associated with drought-induced embolism in angiosperms. THE NEW PHYTOLOGIST 2022; 236:2019-2036. [PMID: 36039697 DOI: 10.1111/nph.18447] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 08/03/2022] [Indexed: 06/15/2023]
Abstract
Hydraulic failure resulting from drought-induced embolism in the xylem of plants is a key determinant of reduced productivity and mortality. Methods to assess this vulnerability are difficult to achieve at scale, leading to alternative metrics and correlations with more easily measured traits. These efforts have led to the longstanding and pervasive assumed mechanistic link between vessel diameter and vulnerability in angiosperms. However, there are at least two problems with this assumption that requires critical re-evaluation: (1) our current understanding of drought-induced embolism does not provide a mechanistic explanation why increased vessel width should lead to greater vulnerability, and (2) the most recent advancements in nanoscale embolism processes suggest that vessel diameter is not a direct driver. Here, we review data from physiological and comparative wood anatomy studies, highlighting the potential anatomical and physicochemical drivers of embolism formation and spread. We then put forward key knowledge gaps, emphasising what is known, unknown and speculation. A meaningful evaluation of the diameter-vulnerability link will require a better mechanistic understanding of the biophysical processes at the nanoscale level that determine embolism formation and spread, which will in turn lead to more accurate predictions of how water transport in plants is affected by drought.
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Affiliation(s)
- Frederic Lens
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA, Leiden, the Netherlands
- Leiden University, Institute of Biology Leiden, Plant Sciences, Sylviusweg 72, 2333 BE, Leiden, the Netherlands
| | - Sean M Gleason
- Water Management and Systems Research Unit, United States Department of Agriculture, Agricultural Research Service, Fort Collins, CO, 80526, USA
| | - Giovanni Bortolami
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA, Leiden, the Netherlands
| | - Craig Brodersen
- School of the Environment, Yale University, New Haven, CT, 06511, USA
| | - Sylvain Delzon
- University of Bordeaux, INRAE, BIOGECO, 33615, Pessac, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, D-89081, Ulm, Germany
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Guan X, Werner J, Cao KF, Pereira L, Kaack L, McAdam SAM, Jansen S. Stem and leaf xylem of angiosperm trees experiences minimal embolism in temperate forests during two consecutive summers with moderate drought. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:1208-1223. [PMID: 34990084 DOI: 10.1111/plb.13384] [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: 09/27/2021] [Accepted: 12/02/2021] [Indexed: 06/14/2023]
Abstract
Drought events may increase the likelihood that the plant water transport system becomes interrupted by embolism. Yet our knowledge about the temporal frequency of xylem embolism in the field is frequently lacking, as it requires detailed, long-term measurements. We measured xylem embolism resistance and midday xylem water potentials during the consecutive summers of 2019 and 2020 to estimate maximum levels of embolism in leaf and stem xylem of ten temperate angiosperm tree species. We also studied vessel and pit membrane characteristics based on light and electron microscopy to corroborate potential differences in embolism resistance between leaves and stems. Apart from A. pseudoplatanus and Q. petraea, eight species experienced minimum xylem water potentials that were close to or below those required to initiate embolism. Water potentials corresponding to ca. 12% loss of hydraulic conductivity (PLC) could occur in six species, while considerable levels of embolism around 50% PLC were limited to B. pendula and C. avellana. There was a general agreement in embolism resistance between stems and leaves, with leaves being equally or more resistant than stems. Also, xylem embolism resistance was significantly correlated to intervessel pit membrane thickness (TPM ) for stems, but not to vessel diameter and total intervessel pit membrane surface area of a vessel. Our data indicate that low amounts of embolism occur in most species during moderate summer drought, and that considerable levels of embolism are uncommon. Moreover, our experimental and TPM data show that leaf xylem is generally no more vulnerable than stem xylem.
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Affiliation(s)
- X Guan
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - J Werner
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - K-F Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilisation of Subtropical Agro-Bioresources, Guangxi University, Nanning, Guangxi, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, China
| | - L Pereira
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - L Kaack
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - S A M McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - S Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
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8
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Knüver T, Bär A, Ganthaler A, Gebhardt T, Grams TEE, Häberle K, Hesse BD, Losso A, Tomedi I, Mayr S, Beikircher B. Recovery after long-term summer drought: Hydraulic measurements reveal legacy effects in trunks of Picea abies but not in Fagus sylvatica. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:1240-1253. [PMID: 35611757 PMCID: PMC10084041 DOI: 10.1111/plb.13444] [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: 10/29/2021] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Climate change is expected to increase the frequency and intensity of summer droughts. Sufficient drought resistance, the ability to acclimate to and/or recover after drought, is thus crucial for forest tree species. However, studies on the hydraulics of mature trees during and after drought in natura are scarce. In this study, we analysed trunk water content (electrical resistivity: ER) and further hydraulic (water potential, sap flow density, specific hydraulic conductivity, vulnerability to embolism) as well as wood anatomical traits (tree ring width, conduit diameter, conduit wall reinforcement) of drought-stressed (artificially induced summer drought via throughfall-exclusion) and unstressed Picea abies and Fagus sylvatica trees. In P. abies, ER indicated a strong reduction in trunk water content after 5 years of summer drought, corresponding to significantly lower pre-dawn leaf water potential and xylem sap flow density. Vulnerability to embolism tended to be higher in drought-stressed trees. In F. sylvatica, only small differences between drought-stressed and control trees were observed. Re-watering led to a rapid increase in water potentials and xylem sap flow of both drought-stressed trees, and to increased growth rates in the next growing season. ER analyses revealed lower trunk water content in P. abies trees growing on throughfall-exclusion plots even 1 year after re-watering, indicating a limited capacity to restore internal water reserves. Results demonstrated that P. abies is more susceptible to recurrent summer drought than F. sylvatica, and can exhibit long-lasting and pronounced legacy effects in trunk water reserves.
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Affiliation(s)
- T. Knüver
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - A. Bär
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - A. Ganthaler
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - T. Gebhardt
- Technical University of MunichSchool of Life SciencesProfessorship for Land Surface‐Atmosphere Interactions AG Ecophysiology of PlantsFreisingGermany
| | - T. E. E. Grams
- Technical University of MunichSchool of Life SciencesProfessorship for Land Surface‐Atmosphere Interactions AG Ecophysiology of PlantsFreisingGermany
| | - K.‐H. Häberle
- Technical University of MunichSchool of Life SciencesChair of Restoration EcologyFreisingGermany
| | - B. D. Hesse
- Technical University of MunichSchool of Life SciencesProfessorship for Land Surface‐Atmosphere Interactions AG Ecophysiology of PlantsFreisingGermany
| | - A. Losso
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondAustralia
| | - I. Tomedi
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - S. Mayr
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - B. Beikircher
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
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9
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Geisler M, Buerki S, Serpe MD. Herbivory Amplifies Adverse Effects of Drought on Seedling Recruitment in a Keystone Species of Western North American Rangelands. PLANTS (BASEL, SWITZERLAND) 2022; 11:2628. [PMID: 36235494 PMCID: PMC9573362 DOI: 10.3390/plants11192628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/01/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Biotic interactions can affect a plant's ability to withstand drought. Such an effect may impact the restoration of the imperiled western North American sagebrush steppe, where seedlings are exposed to summer drought. This study investigated the impact of herbivory on seedlings' drought tolerance for a keystone species in this steppe, the shrub Artemisia tridentata. Herbivory effects were investigated in two field experiments where seedlings were without tree protectors or within plastic or metal-mesh tree protectors. Treatment effects were statistically evaluated on herbivory, survival, leaf water potential, and inflorescence development. Herbivory occurrence was 80% higher in seedlings without protectors. This damage occurred in early spring and was likely caused by ground squirrels. Most plants recovered, but herbivory was associated with higher mortality during the summer when seedlings experienced water potentials between -2.5 and -7 MPa. However, there were no differences in water potential between treatments, suggesting that the browsed plants were less tolerant of the low water potentials experienced. Twenty months after outplanting, the survival of plants without protectors was 40 to 60% lower than those with protectors. The percentage of live plants developing inflorescences was approximately threefold higher in plants with protectors. Overall, spring herbivory amplified susceptibility to drought and delayed reproductive development.
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10
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Oliveira LA, Cardoso AA, Andrade MT, Pereira TS, Araújo WL, Santos GA, Damatta FM, Martins SCV. Exploring leaf hydraulic traits to predict drought tolerance of Eucalyptus clones. TREE PHYSIOLOGY 2022; 42:1750-1761. [PMID: 35388901 DOI: 10.1093/treephys/tpac040] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
Ongoing changes in climate, and the consequent mortality of natural and cultivated forests across the globe, highlight the urgent need to understand the plant traits associated with greater tolerance to drought. Here, we aimed at assessing key foliar traits, with a focus on the hydraulic component, that could confer a differential ability to tolerate drought in three commercial hybrids of the most important Eucalyptus species utilized in tropical silviculture: E. urophyla, E. grandis and E. camaldulensis. All genotypes exhibited similar water potential when the 90% stomatal closure (Ψgs90) occurs with Ψgs90 always preceding the start of embolism events. The drought-tolerant hybrid showed a higher leaf resistance to embolism, but the leaf hydraulic efficiency was similar among all genotypes. Other traits presented by the drought-tolerant hybrid were a higher cell wall reinforcement, lower value of osmotic potential at full turgor and greater bulk modulus of elasticity. We also identified that the leaf capacitance after the turgor loss, the ratio between cell wall thickness (t) and lumen breadth (b) ratio (t/b)3, and the minimal conductance might be good proxies for screening drought-tolerant Eucalyptus genotypes. Our findings suggest that xylem resistance to embolism can be an important component of drought tolerance in Eucalyptus in addition to other traits aimed at delaying the development of high tensions in the xylem. Highlight Drought tolerance in tropical Eucalyptus hybrids encompasses a high leaf resistance to embolism and a suite of traits aimed at delaying the development of high tensions in the xylem.
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Affiliation(s)
- Leonardo A Oliveira
- Departmento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Amanda A Cardoso
- Departmento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Moab T Andrade
- Departmento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Talitha S Pereira
- Departmento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Wagner L Araújo
- Departmento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Gleison A Santos
- Departmento de Engenharia Florestal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Fábio M Damatta
- Departmento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Samuel C V Martins
- Departmento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
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11
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Levionnois S, Kaack L, Heuret P, Abel N, Ziegler C, Coste S, Stahl C, Jansen S. Pit characters determine drought-induced embolism resistance of leaf xylem across 18 Neotropical tree species. PLANT PHYSIOLOGY 2022; 190:371-386. [PMID: 35567500 PMCID: PMC9434246 DOI: 10.1093/plphys/kiac223] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 04/19/2022] [Indexed: 05/16/2023]
Abstract
Embolism spreading in xylem is an important component of plant drought resistance. Since embolism resistance has been shown to be mechanistically linked to pit membrane characters in stem xylem, we speculate that similar mechanisms account for leaf xylem. We conducted transmission electron microscopy to investigate pit membrane characters in leaf xylem across 18 Neotropical tree species. We also conducted gold perfusion and polar lipid detection experiments on three species covering the full range of leaf embolism resistance. We then related these observations to previously published data on embolism resistance of leaf xylem. We also incorporated previously published data on stem embolism resistance and stem xylem pit membranes to investigate the link between vulnerability segmentation (i.e. difference in embolism resistance) and leaf-stem anatomical variation. Maximum pit membrane thickness (Tpm,max) and the pit membrane thickness-to-diameter ratio (Tpm,max/Dpm) were predictive of leaf embolism resistance, especially when vestured pits were taken into account. Variation in Tpm,max/Dpm was the only trait predictive of vulnerability segmentation between leaves and stems. Gold particles of 5- and 10-nm infiltrated pit membranes in three species, while the entry of 50-nm particles was blocked. Moreover, polar lipids were associated with inner conduit walls and pits. Our results suggest that mechanisms related to embolism spreading are determined by Tpm, pore constrictions (i.e. the narrowest bottlenecks along pore pathways), and lipid surfactants, which are largely similar between leaf and stem xylem and between temperate and tropical trees. However, our mechanistic understanding of embolism propagation and the functional relevance of Tpm,max/Dpm remains elusive.
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Affiliation(s)
| | - Lucian Kaack
- Institute of Systematic Botany and Ecology, Ulm University, Ulm D-89081, Germany
| | | | - Nina Abel
- Institute of Systematic Botany and Ecology, Ulm University, Ulm D-89081, Germany
| | - Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou 97310, France
- Université de Lorraine, AgroParisTech, INRAE, UMR SILVA, Nancy 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
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12
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Jiang (蒋国凤) GF, Li (李溯源) SY, Li (李艺蝉) YC, Roddy AB. Coordination of hydraulic thresholds across roots, stems, and leaves of two co-occurring mangrove species. PLANT PHYSIOLOGY 2022; 189:2159-2174. [PMID: 35640109 PMCID: PMC9342987 DOI: 10.1093/plphys/kiac240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/09/2022] [Indexed: 05/30/2023]
Abstract
Mangroves are frequently inundated with saline water and have evolved different anatomical and physiological mechanisms to filter and, in some species, excrete excess salt from the water they take up. Because salts impose osmotic stress, interspecific differences in salt tolerance and salt management strategy may influence physiological responses to drought throughout the entire plant hydraulic pathway, from roots to leaves. Here, we characterized embolism vulnerability simultaneously in leaves, stems, and roots of seedlings of two mangrove species (Avicennia marina and Bruguiera gymnorrhiza) along with turgor-loss points in roots and leaves and xylem anatomical traits. In both species, the water potentials causing 50% of total embolism were less negative in roots and leaves than they were in stems, but the water potentials causing incipient embolism (5%) were similar in roots, stems, and leaves. Stomatal closure in leaves and turgor loss in both leaves and roots occurred at water potentials only slightly less negative than the water potentials causing 5% of total embolism. Xylem anatomical traits were unrelated to vulnerability to embolism. Vulnerability segmentation may be important in limiting embolism spread into stems from more vulnerable roots and leaves. Interspecific differences in salt tolerance affected hydraulic traits from roots to leaves: the salt-secretor A. marina lost turgor at more negative water potentials and had more embolism-resistant xylem than the salt-excluder B. gymnorrhiza. Characterizing physiological thresholds of roots may help to explain recent mangrove mortality after drought and extended saltwater inundation.
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Affiliation(s)
| | - Su-Yuan Li (李溯源)
- Guangxi Key Laboratory of Forest Ecology and Conservation, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China
| | - Yi-Chan Li (李艺蝉)
- Guangxi Key Laboratory of Forest Ecology and Conservation, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China
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13
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Cardoso AA, Kane CN, Rimer IM, McAdam SAM. Seeing is believing: what visualising bubbles in the xylem has revealed about plant hydraulic function. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:759-772. [PMID: 35718950 DOI: 10.1071/fp21326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
Maintaining water transport in the xylem is critical for vascular plants to grow and survive. The drought-induced accumulation of embolism, when gas enters xylem conduits, causes declines in hydraulic conductance (K ) and is ultimately lethal. Several methods can be used to estimate the degree of embolism in xylem, from measuring K in tissues to directly visualising embolism in conduits. One method allowing a direct quantification of embolised xylem area is the optical vulnerability (OV) technique. This method has been used across different organs and has a high spatial and temporal resolution. Here, we review studies using the OV technique, discuss the main advantages and disadvantages of this method, and summarise key advances arising from its use. Vulnerability curves generated by the OV method are regularly comparable to other methods, including the centrifuge and X-ray microtomography. A major advantage of the OV technique over other methods is that it can be simultaneously used to determine in situ embolism formation in leaves, stems and roots, in species spanning the phylogeny of land plants. The OV method has been used to experimentally investigate the spreading of embolism through xylem networks, associate embolism with downstream tissue death, and observe embolism formation in the field.
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Affiliation(s)
- Amanda A Cardoso
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Cade N Kane
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Ian M Rimer
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Scott A M McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
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14
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Britton TG, Brodribb TJ, Richards SA, Ridley C, Hovenden MJ. Canopy damage during a natural drought depends on species identity, physiology and stand composition. THE NEW PHYTOLOGIST 2022; 233:2058-2070. [PMID: 34850394 DOI: 10.1111/nph.17888] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
Vulnerability to xylem cavitation is a strong predictor of drought-induced damage in forest communities. However, biotic features of the community itself can influence water availability at the individual tree-level, thereby modifying patterns of drought damage. Using an experimental forest in Tasmania, Australia, we determined the vulnerability to cavitation (leaf P50 ) of four tree species and assessed the drought-induced canopy damage of 2944 6-yr-old trees after an extreme natural drought episode. We examined how individual damage was related to their size and the density and species identity of neighbouring trees. The two co-occurring dominant tree species, Eucalyptus delegatensis and Eucalyptus regnans, were the most vulnerable to drought-induced xylem cavitation and both species suffered significantly greater damage than neighbouring, subdominant species Pomaderris apetala and Acacia dealbata. While the two eucalypts had similar leaf P50 values, E. delegatensis suffered significantly greater damage, which was strongly related to the density of neighbouring P. apetala. Damage in E. regnans was less impacted by neighbouring plants and smaller trees of both eucalypts sustained significantly more damage than larger trees. Our findings demonstrate that natural drought damage is influenced by individual plant physiology as well as the composition, physiology and density of the surrounding stand.
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Affiliation(s)
- Travis G Britton
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Timothy J Brodribb
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Shane A Richards
- School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Chantelle Ridley
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Mark J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tas., 7001, Australia
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15
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Sheridan RA, Nackley LL. Applying Plant Hydraulic Physiology Methods to Investigate Desiccation During Prolonged Cold Storage of Horticultural Trees. FRONTIERS IN PLANT SCIENCE 2022; 13:818769. [PMID: 35283873 PMCID: PMC8908214 DOI: 10.3389/fpls.2022.818769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Plant nursery production systems are a multi-billion-dollar, international, and horticultural industry that depends on storing and shipping live plants. The storage environment represents potentially desiccating and even fatal conditions for dormant, bareroot, and deciduous horticulture crops, like orchard trees, forestry trees, ornamental trees, and grapevines. When tree mortality is considered within a plant hydraulic framework, plants experiencing water stress are thought to ultimately die from hydraulic failure or carbon starvation. We hypothesized that the hydraulic framework can be applied to stored crops to determine if hydraulic failure or carbon starvation could be attributed to mortality. We used deciduous trees as model species because they are important horticultural crops and provide a diversity of hydraulic strategies. We selected cultivars from six genera: Acer, Amelanchier, Gleditsia, Gymnocladus, Malus, and Quercus. For each cultivar, we measured stem hydraulic conductance and vulnerability to embolism. On a weekly basis for 14 weeks (March-June), we removed trees of each cultivar from cold storage (1-2°C). Each week and for each cultivar, we measured stem water potential and water content (n = 7) and planted trees to track survival and growth (n = 10). At three times during this period, we also measured non-structural carbohydrates. Our results showed that for four cultivars (Acer, Amelanchier, Malus, and Quercus), the stem water potentials measured in trees removed from storage did not exceed stem P 50, the water potential at which 50% of stem hydraulic conductivity is lost. This suggests that the water transport system remains intact during storage. For two cultivars (Gleditsia and Gymnocladus), the water potential measured on trees out of storage exceeded stem P 50, yet planted trees from all weeks survived and grew. In the 14 weeks, there were no significant changes or directional trends in stem water potential, water content, or NSC for most cultivars, with a few exceptions. Overall, the results show that the trees did not experience detrimental water relations or carbon starvation thresholds. Our results suggest that many young deciduous trees are resilient to conditions caused by prolonged dormancy and validate the current storage methods. This experiment provides an example of how a mechanistically based understanding of physiological responses can inform cold storage regimes in nursery tree production.
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Affiliation(s)
| | - Lloyd L. Nackley
- North Willamette Research and Extension Center, Oregon State University, Corvallis, OR, United States
- Department of Horticulture, Oregon State University, Corvallis, OR, United States
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16
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Ganthaler A, Bär A, Dämon B, Losso A, Nardini A, Dullin C, Tromba G, von Arx G, Mayr S. Alpine dwarf shrubs show high proportions of nonfunctional xylem: Visualization and quantification of species-specific patterns. PLANT, CELL & ENVIRONMENT 2022; 45:55-68. [PMID: 34783044 DOI: 10.1111/pce.14226] [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: 04/13/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Xylem conductive capacity is a key determinant of plant hydraulic function and intimately linked to photosynthesis and productivity, but can be impeded by temporary or permanent conduit dysfunctions. Here we show that persistent xylem dysfunctions in unstressed plants are frequent in Alpine dwarf shrubs and occur in various but species-specific cross-sectional patterns. Combined synchrotron micro-computed tomography (micro-CT) imaging, xylem staining, and flow measurements in saturated samples of six widespread Ericaceae species evidence a high proportion (19%-50%) of hydraulically nonfunctional xylem areas in the absence of drought stress, with regular distribution of dysfunctions between or within growth rings. Dysfunctions were only partly reversible and reduced the specific hydraulic conductivity to 1.38 to 3.57 ×10-4 m2 s-1 MPa-1 . Decommission of inner growth rings was clearly related to stem age and a higher vulnerability to cavitation of older rings, while the high proportion of nonfunctional conduits in each annual ring needs further investigations. The lower the xylem fraction contributing to the transport function, the higher was the hydraulic efficiency of conducting xylem areas. Improved understanding of the functional lifespan of xylem elements and the prevalence and nature of dysfunctions is critical to correctly assess structure-function relationships and whole-plant hydraulic strategies.
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Affiliation(s)
- Andrea Ganthaler
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Andreas Bär
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Birgit Dämon
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Adriano Losso
- Department of Botany, University of Innsbruck, Innsbruck, Austria
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Trieste, Italy
| | - Christian Dullin
- Elettra-Sincrotrone Trieste, Basovizza, Italy
- Institute for Diagnostic and Interventional Radiology, University Medical Center, Göttingen, Germany
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
- Diagnostic and Interventional Radiology, University Hospital, Heidelberg, Germany
| | | | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Innsbruck, Austria
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17
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Lübbe T, Lamarque LJ, Delzon S, Torres Ruiz JM, Burlett R, Leuschner C, Schuldt B. High variation in hydraulic efficiency but not xylem safety between roots and branches in four temperate broad‐leaved tree species. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13975] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Torben Lübbe
- Plant Ecology Albrecht von Haller Institute for Plant Sciences University of Goettingen Goettingen Germany
| | - Laurent J. Lamarque
- Département des Sciences de l'environnement Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada
- University of Bordeaux INRAE BIOGECO Pessac France
| | | | | | | | - Christoph Leuschner
- Plant Ecology Albrecht von Haller Institute for Plant Sciences University of Goettingen Goettingen Germany
| | - Bernhard Schuldt
- Plant Ecology Albrecht von Haller Institute for Plant Sciences University of Goettingen Goettingen Germany
- Julius‐von‐Sachs‐Institute of Biological Sciences, Ecophysiology and Vegetation Ecology University of Würzburg Würzburg Germany
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18
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Hartmann H, Link RM, Schuldt B. A whole-plant perspective of isohydry: stem-level support for leaf-level plant water regulation. TREE PHYSIOLOGY 2021; 41:901-905. [PMID: 33594416 PMCID: PMC8827077 DOI: 10.1093/treephys/tpab011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Affiliation(s)
| | - Roman Mathias Link
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
| | - Bernhard Schuldt
- Julius-von-Sachs-Institute of Biological Sciences, Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Platz 3, 97082 Würzburg, Germany
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19
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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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20
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Schenk HJ, Jansen S, Hölttä T. Positive pressure in xylem and its role in hydraulic function. THE NEW PHYTOLOGIST 2021; 230:27-45. [PMID: 33206999 DOI: 10.1111/nph.17085] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 10/13/2020] [Indexed: 05/29/2023]
Abstract
Although transpiration-driven transport of xylem sap is well known to operate under absolute negative pressure, many terrestrial, vascular plants show positive xylem pressure above atmospheric pressure on a seasonal or daily basis, or during early developmental stages. The actual location and mechanisms behind positive xylem pressure remain largely unknown, both in plants that show seasonal xylem pressure before leaf flushing, and those that show a diurnal periodicity of bleeding and guttation. Available evidence shows that positive xylem pressure can be driven based on purely physical forces, osmotic exudation into xylem conduits, or hydraulic pressure in parenchyma cells associated with conduits. The latter two mechanisms may not be mutually exclusive and can be understood based on a similar modelling scenario. Given the renewed interest in positive xylem pressure, this review aims to provide a constructive way forward by discussing similarities and differences of mechanistic models, evaluating available evidence for hydraulic functions, such as rehydration of tissues, refilling of water stores, and embolism repair under positive pressure, and providing recommendations for future research, including methods that avoid or minimise cutting artefacts.
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Affiliation(s)
- H Jochen Schenk
- Department of Biological Science, California State University Fullerton, PO Box 6850, Fullerton, CA, 92834, USA
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, D-89081, Germany
| | - Teemu Hölttä
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, PO Box 27, Helsinki, FI-00014, Finland
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21
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Koddenberg T, Greving I, Hagemann J, Flenner S, Krause A, Laipple D, Klein KC, Schmitt U, Schuster M, Wolf A, Seifert M, Ludwig V, Funk S, Militz H, Nopens M. Three-dimensional imaging of xylem at cell wall level through near field nano holotomography. Sci Rep 2021; 11:4574. [PMID: 33633184 PMCID: PMC7907381 DOI: 10.1038/s41598-021-83885-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 02/08/2021] [Indexed: 11/09/2022] Open
Abstract
Detailed imaging of the three-dimensionally complex architecture of xylary plants is important for studying biological and mechanical functions of woody plants. Apart from common two-dimensional microscopy, X-ray micro-computed tomography has been established as a three-dimensional (3D) imaging method for studying the hydraulic function of wooden plants. However, this X-ray imaging method can barely reach the resolution needed to see the minute structures (e.g. pit membrane). To complement the xylem structure with 3D views at the nanoscale level, X-ray near-field nano-holotomography (NFH) was applied to analyze the wood species Pinus sylvestris and Fagus sylvatica. The demanded small specimens required focused ion beam (FIB) application. The FIB milling, however, influenced the image quality through gallium implantation on the cell-wall surfaces. The measurements indicated that NFH is appropriate for imaging wood at nanometric resolution. With a 26 nm voxel pitch, the structure of the cell-wall surface in Pinus sylvestris could be visualized in genuine detail. In wood of Fagus sylvatica, the structure of a pit pair, including the pit membrane, between two neighboring fibrous cells could be traced tomographically.
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Affiliation(s)
- Tim Koddenberg
- Wood Biology and Wood Products, Faculty of Forest Sciences and Forest Ecology, University of Goettingen, Büsgenweg 4, 37077, Göttingen, Germany
| | - Imke Greving
- Institute of Materials Physics, Helmholtz-Zentrum Geesthacht, Max Plank Straße1, 21502, Geesthacht, Germany
| | - Johannes Hagemann
- Deutsches Elektronen Synchrotron-DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Silja Flenner
- Institute of Materials Physics, Helmholtz-Zentrum Geesthacht, Max Plank Straße1, 21502, Geesthacht, Germany
| | - Andreas Krause
- Thünen-Institute of Wood Research, Leuschnerstraße 91, Hamburg-Bergedorf, 21031, Hamburg, Germany
| | - Daniel Laipple
- Institute of Materials Physics, Helmholtz-Zentrum Geesthacht, Max Plank Straße1, 21502, Geesthacht, Germany
| | - Kim C Klein
- Wood Biology and Wood Products, Faculty of Forest Sciences and Forest Ecology, University of Goettingen, Büsgenweg 4, 37077, Göttingen, Germany
| | - Uwe Schmitt
- Thünen-Institute of Wood Research, Leuschnerstraße 91, Hamburg-Bergedorf, 21031, Hamburg, Germany
| | - Max Schuster
- Erlangen Centre for Astroparticle Physics, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erwin-Rommel-Strasse 1, 91058, Erlangen, Germany
| | - Andreas Wolf
- Erlangen Centre for Astroparticle Physics, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erwin-Rommel-Strasse 1, 91058, Erlangen, Germany
| | - Maria Seifert
- Erlangen Centre for Astroparticle Physics, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erwin-Rommel-Strasse 1, 91058, Erlangen, Germany
| | - Veronika Ludwig
- Erlangen Centre for Astroparticle Physics, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erwin-Rommel-Strasse 1, 91058, Erlangen, Germany
| | - Stefan Funk
- Erlangen Centre for Astroparticle Physics, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erwin-Rommel-Strasse 1, 91058, Erlangen, Germany
| | - Holger Militz
- Wood Biology and Wood Products, Faculty of Forest Sciences and Forest Ecology, University of Goettingen, Büsgenweg 4, 37077, Göttingen, Germany
| | - Martin Nopens
- Thünen-Institute of Wood Research, Leuschnerstraße 91, Hamburg-Bergedorf, 21031, Hamburg, Germany.
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22
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Walthert L, Ganthaler A, Mayr S, Saurer M, Waldner P, Walser M, Zweifel R, von Arx G. From the comfort zone to crown dieback: Sequence of physiological stress thresholds in mature European beech trees across progressive drought. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 753:141792. [PMID: 33207466 DOI: 10.1016/j.scitotenv.2020.141792] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/14/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
Drought responses of mature trees are still poorly understood making it difficult to predict species distributions under a warmer climate. Using mature European beech (Fagus sylvatica L.), a widespread and economically important tree species in Europe, we aimed at developing an empirical stress-level scheme to describe its physiological response to drought. We analysed effects of decreasing soil and leaf water potential on soil water uptake, stem radius, native embolism, early defoliation and crown dieback with comprehensive measurements from overall nine hydrologically distinct beech stands across Switzerland, including records from the exceptional 2018 drought and the 2019/2020 post-drought period. Based on the observed responses to decreasing water potential we derived the following five stress levels: I (predawn leaf water potential >-0.4 MPa): no detectable hydraulic limitations; II (-0.4 to -1.3): persistent stem shrinkage begins and growth ceases; III (-1.3 to -2.1): onset of native embolism and defoliation; IV (-2.1 to -2.8): onset of crown dieback; V (<-2.8): transpiration ceases and crown dieback is >20%. Our scheme provides, for the first time, quantitative thresholds regarding the physiological downregulation of mature European beech trees under drought and therefore synthesises relevant and fundamental information for process-based species distribution models. Moreover, our study revealed that European beech is drought vulnerable, because it still transpires considerably at high levels of embolism and because defoliation occurs rather as a result of embolism than preventing embolism. During the 2018 drought, an exposure to the stress levels III-V of only one month was long enough to trigger substantial crown dieback in beech trees on shallow soils. On deep soils with a high water holding capacity, in contrast, water reserves in deep soil layers prevented drought stress in beech trees. This emphasises the importance to include local data on soil water availability when predicting the future distribution of European beech.
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Affiliation(s)
- Lorenz Walthert
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland.
| | - Andrea Ganthaler
- Department of Botany, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Matthias Saurer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Peter Waldner
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Marco Walser
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
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23
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Chen YJ, Maenpuen P, Zhang YJ, Barai K, Katabuchi M, Gao H, Kaewkamol S, Tao LB, Zhang JL. Quantifying vulnerability to embolism in tropical trees and lianas using five methods: can discrepancies be explained by xylem structural traits? THE NEW PHYTOLOGIST 2021; 229:805-819. [PMID: 32929748 DOI: 10.1111/nph.16927] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 08/18/2020] [Indexed: 05/21/2023]
Abstract
Vulnerability curves (VCs) describe the loss of hydraulic conductance against increasing xylem tension, providing valuable insights about the response of plant water transport to water stress. Techniques to construct VCs have been developed and modified continuously, but controversies continue. We compared VCs constructed using the bench-top dehydration (BD), air-injection-flow (AI), pneumatic-air-discharge (PAD), optical (OP) and X-ray-computed microtomography (MicroCT) methods for tropical trees and lianas with contrasting vessel lengths. The PAD method generated highly vulnerable VCs, the AI method intermediate VCs, whereas the BD, OP and MicroCT methods produced comparable and more resistant VCs. Vessel-length and diameter accounted for the overestimation ratio of vulnerability estimated using the AI but not the PAD method. Compared with directly measured midday embolism levels, the PAD and AI methods substantially overestimated embolism, whereas the BD, MicroCT and OP methods provided more reasonable estimations. Cut-open vessels, uncertainties in maximum air volume estimations, sample-length effects, tissue cracks and shrinkage together may impede the reliability of the PAD method. In conclusion, we validate the BD, OP and MicroCT methods for tropical plants, whereas the PAD and AI need further mechanistic testing. Therefore, applications of VCs in estimating plant responses to drought need to be cautious.
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Affiliation(s)
- Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan, 653300, China
| | - Phisamai Maenpuen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME, 04469, USA
| | - Kallol Barai
- School of Biology and Ecology, University of Maine, Orono, ME, 04469, USA
| | - Masatoshi Katabuchi
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Hui Gao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Sasiwimol Kaewkamol
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lian-Bin Tao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Jiao-Lin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
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24
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Unterholzner L, Carrer M, Bär A, Beikircher B, Dämon B, Losso A, Prendin AL, Mayr S. Juniperus communis populations exhibit low variability in hydraulic safety and efficiency. TREE PHYSIOLOGY 2020; 40:1668-1679. [PMID: 32785622 DOI: 10.1093/treephys/tpaa103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 08/07/2020] [Indexed: 06/11/2023]
Abstract
The performance and distribution of woody species strongly depend on their adjustment to environmental conditions based on genotypic and phenotypic properties. Since more intense and frequent drought events are expected due to climate change, xylem hydraulic traits will play a key role under future conditions, and thus, knowledge of hydraulic variability is of key importance. In this study, we aimed to investigate the variability in hydraulic safety and efficiency of the conifer shrub Juniperus communis based on analyses along an elevational transect and a common garden approach. We studied (i) juniper plants growing between 700 and 2000 m a.s.l. Innsbruck, Austria, and (ii) plants grown in the Innsbruck botanical garden (Austria) from seeds collected at different sites across Europe (France, Austria, Ireland, Germany and Sweden). Due to contrasting environmental conditions at different elevation and provenance sites and the wide geographical study area, pronounced variation in xylem hydraulics was expected. Vulnerability to drought-induced embolisms (hydraulic safety) was assessed via the Cavitron and ultrasonic acoustic emission techniques, and the specific hydraulic conductivity (hydraulic efficiency) via flow measurements. Contrary to our hypothesis, relevant variability in hydraulic safety and efficiency was neither observed across elevations, indicating a low phenotypic variation, nor between provenances, despite expected genotypic differences. Interestingly, the provenance from the most humid and warmest site (Ireland) and the northernmost provenance (Sweden) showed the highest and the lowest embolism resistance, respectively. The hydraulic conductivity was correlated with plant height, which indicates that observed variation in hydraulic traits was mainly related to morphological differences between plants. We encourage future studies to underlie anatomical traits and the role of hydraulics for the broad ecological amplitude of J. communis.
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Affiliation(s)
| | - Marco Carrer
- Department TeSAF, Università degli Studi di Padova, Legnaro (PD) 35122, Italy
| | - Andreas Bär
- Institut für Botanik, Universität Innsbruck, Innsbruck 6020, Austria
| | | | - Birgit Dämon
- Institut für Botanik, Universität Innsbruck, Innsbruck 6020, Austria
| | - Adriano Losso
- Institut für Botanik, Universität Innsbruck, Innsbruck 6020, Austria
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW 2753, Australia
| | | | - Stefan Mayr
- Institut für Botanik, Universität Innsbruck, Innsbruck 6020, Austria
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25
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Zhang C, Wang M, Chen J, Gao X, Shao C, Lv Z, Jiao H, Xu H, Shen C. Survival strategies based on the hydraulic vulnerability segmentation hypothesis, for the tea plant [Camellia sinensis(L.) O. Kuntze] in long-term drought stress condition. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 156:484-493. [PMID: 33038691 DOI: 10.1016/j.plaphy.2020.09.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/23/2020] [Indexed: 05/23/2023]
Abstract
Tea plants are important economic perennial crops that can be negatively impacted by drought stress (DS). However, their survival strategies in long-term DS conditions and the accumulation and influence of metabolites and mineral elements (MEs) in their organs, when facing hydraulic vulnerability segmentation, require further investigation. The MEs and metabolites in the leaf, stem, and root after long-term DS (20 d) were examined here, using inductively coupled plasma optical emission spectrometry (ICP-OES) and liquid chromatograph-mass spectrometry (LC-MS). The accumulation patterns of 116 differentially accumulated metabolites (DAMs) and nine MEs were considerably affected in all organs. The concentration of all MEs varied significantly in at least one organ, while the K and Ca levels were markedly altered in all three. Most DAM levels increased in the stem but decreased in the root and leaf, implying that vulnerability segmentation may occur with long-term DS. The typical nitrogen- and carbon-compound levels similarly increased in the stem and decreased in the leaf and root, as the plant might respond to long-term DS by stabilizing respiration, promoting nitrogen recycling, and free radical scavenging. Correlation analysis showed several possible DAM-ME interactions and an association between Mn and flavonoids. Thus, survival strategies under long-term DS included sacrificing distal/vulnerable organs and accumulating function-specialized metabolites and MEs to mitigate drought-induced oxidative damage. This is the first study that reports substance fluctuations after long-term DS in different organs of plants, and highlights the need to use whole plants to fully comprehend stress response strategies.
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Affiliation(s)
- Chenyu Zhang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China.
| | - Minhan Wang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Jianjiao Chen
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Xizhi Gao
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Chenyu Shao
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Zhidong Lv
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Haizhen Jiao
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Huaqin Xu
- College of Resources & Environment, Hunan Agricultural University, Changsha, Hunan, 410128, China.
| | - Chengwen Shen
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China.
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26
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Gauthey A, Peters JMR, Carins-Murphy MR, Rodriguez-Dominguez CM, Li X, Delzon S, King A, López R, Medlyn BE, Tissue DT, Brodribb TJ, Choat B. Visual and hydraulic techniques produce similar estimates of cavitation resistance in woody species. THE NEW PHYTOLOGIST 2020; 228:884-897. [PMID: 32542732 DOI: 10.1111/nph.16746] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 06/02/2020] [Indexed: 05/24/2023]
Abstract
Hydraulic failure of the plant vascular system is a principal cause of forest die-off under drought. Accurate quantification of this process is essential to our understanding of the physiological mechanisms underpinning plant mortality. Imaging techniques increasingly are applied to estimate xylem cavitation resistance. These techniques allow for in situ measurement of embolism formation in real time, although the benefits and trade-offs associated with different techniques have not been evaluated in detail. Here we compare two imaging methods, microcomputed tomography (microCT) and optical vulnerability (OV), to standard hydraulic methods for measurement of cavitation resistance in seven woody species representing a diversity of major phylogenetic and xylem anatomical groups. Across the seven species, there was strong agreement between cavitation resistance values (P50 ) estimated from visualization techniques (microCT and OV) and between visual techniques and hydraulic techniques. The results indicate that visual techniques provide accurate estimates of cavitation resistance and the degree to which xylem hydraulic function is impacted by embolism. Results are discussed in the context of trade-offs associated with each technique and possible causes of discrepancy between estimates of cavitation resistance provided by visual and hydraulic techniques.
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Affiliation(s)
- Alice Gauthey
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Jennifer M R Peters
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Madeline R Carins-Murphy
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tas, 7001, Australia
| | - Celia M Rodriguez-Dominguez
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tas, 7001, Australia
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, 10, Sevilla, 41012, Spain
| | - Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Sylvain Delzon
- UMR BIOGECO, INRA, Univ Bordeaux, Talence, 33450, France
| | - Andrew King
- L'Orme de Merisiers, Synchrotron SOLEIL, 91190 Saint-Aubin-BP48, Gif-sur-Yvette Cedex, France
| | - Rosana López
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Madrid, Spain
- PIAF, INRA, University of Clermont-Auvergne, 63100, Clermont-Ferrand, France
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Tim J Brodribb
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tas, 7001, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
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27
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Peters JMR, Gauthey A, Lopez R, Carins-Murphy MR, Brodribb TJ, Choat B. Non-invasive imaging reveals convergence in root and stem vulnerability to cavitation across five tree species. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:6623-6637. [PMID: 32822502 PMCID: PMC7586747 DOI: 10.1093/jxb/eraa381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 08/18/2020] [Indexed: 05/08/2023]
Abstract
Root vulnerability to cavitation is challenging to measure and under-represented in current datasets. This gap limits the precision of models used to predict plant responses to drought because roots comprise the critical interface between plant and soil. In this study, we measured vulnerability to drought-induced cavitation in woody roots and stems of five tree species (Acacia aneura, Cedrus deodara, Eucalyptus crebra, Eucalytus saligna, and Quercus palustris) with a wide range of xylem anatomies. X-ray microtomography was used to visualize the accumulation of xylem embolism in stems and roots of intact plants that were naturally dehydrated to varying levels of water stress. Vulnerability to cavitation, defined as the water potential causing a 50% loss of hydraulic function (P50), varied broadly among the species (-4.51 MPa to -11.93 MPa in stems and -3.13 MPa to -9.64 MPa in roots). The P50 of roots and stems was significantly related across species, with species that had more vulnerable stems also having more vulnerable roots. While there was strong convergence in root and stem vulnerability to cavitation, the P50 of roots was significantly higher than the P50 of stems in three species. However, the difference in root and stem vulnerability for these species was small; between 1% and 31% of stem P50. Thus, while some differences existed between organs, roots were not dramatically more vulnerable to embolism than stems, and the differences observed were less than those reported in previous studies. Further study is required to evaluate the vulnerability across root orders and to extend these conclusions to a greater number of species and xylem functional types.
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Affiliation(s)
- Jennifer M R Peters
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
- Oak Ridge National Laboratory, Climate Change Science Institute & Environmental Science Division, Oak Ridge, TN, USA
| | - Alice Gauthey
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Rosana Lopez
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
- Departamento de Sistemas y Recursos Naturales. Universidad Politécnica de Madrid, Ciudad Universitaria, Madrid, Spain
| | | | - Timothy J Brodribb
- School of Biological Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
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28
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Levionnois S, Ziegler C, Jansen S, Calvet E, Coste S, Stahl C, Salmon C, Delzon S, Guichard C, Heuret P. Vulnerability and hydraulic segmentations at the stem-leaf transition: coordination across Neotropical trees. THE NEW PHYTOLOGIST 2020; 228:512-524. [PMID: 32496575 DOI: 10.1111/nph.16723] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/18/2020] [Indexed: 05/23/2023]
Abstract
Hydraulic segmentation at the stem-leaf transition predicts higher hydraulic resistance in leaves than in stems. Vulnerability segmentation, however, predicts lower embolism resistance in leaves. Both mechanisms should theoretically favour runaway embolism in leaves to preserve expensive organs such as stems, and should be tested for any potential coordination. We investigated the theoretical leaf-specific conductivity based on an anatomical approach to quantify the degree of hydraulic segmentation across 21 tropical rainforest tree species. Xylem resistance to embolism in stems (flow-centrifugation technique) and leaves (optical visualization method) was quantified to assess vulnerability segmentation. We found a pervasive hydraulic segmentation across species, but with a strong variability in the degree of segmentation. Despite a clear continuum in the degree of vulnerability segmentation, eight species showed a positive vulnerability segmentation (leaves less resistant to embolism than stems), whereas the remaining species studied exhibited a negative or no vulnerability segmentation. The degree of vulnerability segmentation was positively related to the degree of hydraulic segmentation, such that segmented species promote both mechanisms to hydraulically decouple leaf xylem from stem xylem. To what extent hydraulic and vulnerability segmentation determine drought resistance requires further integration of the leaf-stem transition at the whole-plant level, including both xylem and outer xylem tissue.
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Affiliation(s)
- Sébastien Levionnois
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- UMR SILVA, INRAE , Université de Lorraine, Nancy, 54000, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, D-89081, Germany
| | - Emma Calvet
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, 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
| | - Camille Salmon
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Sylvain Delzon
- Univ. Bordeaux , INRAE, BIOGECO, Pessac, F-33615, France
| | - Charlotte Guichard
- 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
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
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29
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Petruzzellis F, Tomasella M, Miotto A, Natale S, Trifilò P, Nardini A. A Leaf Selfie: Using a Smartphone to Quantify Leaf Vulnerability to Hydraulic Dysfunction. PLANTS (BASEL, SWITZERLAND) 2020; 9:E234. [PMID: 32054113 PMCID: PMC7076359 DOI: 10.3390/plants9020234] [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: 12/18/2019] [Revised: 01/21/2020] [Accepted: 02/05/2020] [Indexed: 05/28/2023]
Abstract
Accurate predictions of species distribution under current and future climate conditions require modeling efforts based on clear mechanistic relationships between climate variables and plant physiological functions. Vulnerability of leaves to xylem embolism is a key mechanistic trait that might be included in these modeling efforts. Here, we propose a simple set-up to measure leaf vulnerability to embolism on the basis of the optical method using a smartphone, a light source, and a notebook. Our data show that this proposed set-up can adequately quantify the vulnerability to xylem embolism of leaf major veins in Populus nigra and Ostrya carpinifolia, producing values consistent with those obtained in temperate tree species with other methods, allowing virtually any laboratory to quantify species-specific drought tolerance on the basis of a sound mechanistic trait.
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Affiliation(s)
- Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
| | - Martina Tomasella
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
| | - Andrea Miotto
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
| | - Sara Natale
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
| | - Patrizia Trifilò
- Dipartimento di Scienze chimiche, biologiche, farmaceutiche e ambientali, Università di Messina, Viale Ferdinando Stagno d’Alcontres 31, 98166 Messina, Italy;
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
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30
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Li S, Wang J, Yin Y, Li X, Deng L, Jiang X, Chen Z, Li Y. Investigating Effects of Bordered Pit Membrane Morphology and Properties on Plant Xylem Hydraulic Functions-A Case Study from 3D Reconstruction and Microflow Modelling of Pit Membranes in Angiosperm Xylem. PLANTS (BASEL, SWITZERLAND) 2020; 9:E231. [PMID: 32054100 PMCID: PMC7076482 DOI: 10.3390/plants9020231] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/18/2020] [Accepted: 02/08/2020] [Indexed: 01/12/2023]
Abstract
Pit membranes in between neighboring conduits of xylem play a crucial role in plant water transport. In this review, the morphological characteristics, chemical composition and mechanical properties of bordered pit membranes were summarized and linked with their functional roles in xylem hydraulics. The trade-off between xylem hydraulic efficiency and safety was closely related with morphology and properties of pit membranes, and xylem embolism resistance was also determined by the pit membrane morphology and properties. Besides, to further investigate the effects of bordered pit membranes morphology and properties on plant xylem hydraulic functions, here we modelled three-dimensional structure of bordered pit membranes by applying a deposition technique. Based on reconstructed 3D pit membrane structures, a virtual fibril network was generated to model the microflow pattern across inter-vessel pit membranes. Moreover, the mechanical behavior of intervessel pit membranes was estimated from a single microfibril's mechanical property. Pit membranes morphology varied among different angiosperm and gymnosperm species. Our modelling work suggested that larger pores of pit membranes do not necessarily contribute to major flow rate across pit membranes; instead, the obstructed degree of flow pathway across the pit membranes plays a more important role. Our work provides useful information for studying the mechanism of microfluid flow transport across pit membranes and also sheds light on investigating the response of pit membranes both at normal and stressed conditions, thus improving our understanding on functional roles of pit membranes in xylem hydraulic function. Further work could be done to study the morphological and mechanical response of bordered pit membranes under different dehydrated conditions, as well as the related microflow behavior, based on our constructed model.
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Affiliation(s)
- Shan Li
- Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China; (S.L.); (J.W.); (Y.Y.); (L.D.); (X.J.)
- Wood Collections (WOODPEDIA), Chinese Academy of Forestry, Beijing 100091, China
| | - Jie Wang
- Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China; (S.L.); (J.W.); (Y.Y.); (L.D.); (X.J.)
- Wood Collections (WOODPEDIA), Chinese Academy of Forestry, Beijing 100091, China
| | - Yafang Yin
- Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China; (S.L.); (J.W.); (Y.Y.); (L.D.); (X.J.)
- Wood Collections (WOODPEDIA), Chinese Academy of Forestry, Beijing 100091, China
| | - Xin Li
- College of Forestry, Beijing Forestry University, Beijing 100083, China;
| | - Liping Deng
- Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China; (S.L.); (J.W.); (Y.Y.); (L.D.); (X.J.)
- International Center for Bamboo and Rattan, Beijing 100102, China
| | - Xiaomei Jiang
- Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China; (S.L.); (J.W.); (Y.Y.); (L.D.); (X.J.)
- Wood Collections (WOODPEDIA), Chinese Academy of Forestry, Beijing 100091, China
| | - Zhicheng Chen
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing 100083, China;
| | - Yujun Li
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China
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31
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Li X, Smith R, Choat B, Tissue DT. Drought resistance of cotton (Gossypium hirsutum) is promoted by early stomatal closure and leaf shedding. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:91-98. [PMID: 31825787 DOI: 10.1071/fp19093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 09/06/2019] [Indexed: 05/11/2023]
Abstract
Water relations have been well documented in tree species, but relatively little is known about the hydraulic characteristics of crops. Here, we report on the hydraulic strategy of cotton (Gossypium hirsutum L.). Leaf gas exchange and in vivo embolism formation were monitored simultaneously on plants that were dried down in situ under controlled environment conditions, and xylem vulnerability to embolism of leaves, stems and roots was measured using intact plants. Water potential inducing 50% embolised vessels (P50) in leaves was significantly higher (less negative) than P50 of stems and roots, suggesting that leaves were the most vulnerable organ to embolism. Furthermore, the water potential generating stomatal closure (Pgs) was higher than required to generate embolism formation, and complete stomatal closure always preceded the onset of embolism with declining soil water content. Although protracted drought resulted in massive leaf shedding, stem embolism remained minimal even after ~90% leaf area was lost. Overall, cotton maintained hydraulic integrity during long-term drought stress through early stomatal closure and leaf shedding, thus exhibiting a drought avoidance strategy. Given that water potentials triggering xylem embolism are uncommon under field conditions, cotton is unlikely to experience hydraulic dysfunction except under extreme climates. Results of this study provide physiological evidence for drought resistance in cotton with regard to hydraulics, and may provide guidance in developing irrigation schedules during periods of water shortage.
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Affiliation(s)
- Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Renee Smith
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; and Corresponding author.
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32
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Emilio T, Lamarque LJ, Torres-Ruiz JM, King A, Charrier G, Burlett R, Conejero M, Rudall PJ, Baker WJ, Delzon S. Embolism resistance in petioles and leaflets of palms. ANNALS OF BOTANY 2020; 124:1173-1184. [PMID: 31227829 PMCID: PMC6943700 DOI: 10.1093/aob/mcz104] [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: 01/21/2019] [Accepted: 06/17/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND AIMS Hydraulic studies are currently biased towards conifers and dicotyledonous angiosperms; responses of arborescent monocots to increasing temperature and drought remain poorly known. This study aims to assess xylem resistance to drought-induced embolism in palms. METHODS We quantified embolism resistance via P50 (xylem pressure inducing 50 % embolism or loss of hydraulic conductivity) in petioles and leaflets of six palm species differing in habitat and phylogenetic relatedness using three techniques: in vivo X-ray-based microcomputed tomography, the in situ flow centrifuge technique and the optical vulnerability method. KEY RESULTS Our results show that P50 of petioles varies greatly in the palm family, from -2.2 ± 0.4 MPa in Dypsis baronii to -5.8 ± 0.3 MPa in Rhapis excelsa (mean ± s.e.). No difference or weak differences were found between petioles and leaf blades within species. Surprisingly, where differences occurred, leaflets were less vulnerable to embolism than petioles. Embolism resistance was not correlated with conduit size (r = 0.37, P = 0.11). CONCLUSIONS This study represents the first estimate of drought-induced xylem embolism in palms across biomes and provides the first step towards understanding hydraulic adaptations in long-lived arborescent monocots. It showed an almost 3-fold range of embolism resistance between palm species, as large as that reported in all angiosperms. We found little evidence for hydraulic segmentation between leaflets and petioles in palms, suggesting that when it happens, hydraulic segregation may lack a clear relationship with organ cost or replaceability.
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Affiliation(s)
- Thaise Emilio
- Royal Botanic Gardens, Kew, Richmond, UK
- Programa Nacional de Pós-Doutorado (PNPD), Programa de Pós Graduação em Ecologia, Institute of Biology, University of Campinas (UNICAMP), Brazil
| | | | | | - Andrew King
- Synchrotron SOLEIL, L’Orme de Merisiers, Saint-Aubin, Gif-sur-Yvette Cedex, France
| | | | - Régis Burlett
- BIOGECO, INRA, Université de Bordeaux, Pessac, France
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33
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Liu X, Li Q, Wang F, Sun X, Wang N, Song H, Cui R, Wu P, Du N, Wang H, Wang R. Weak Tradeoff and Strong Segmentation Among Plant Hydraulic Traits During Seasonal Variation in Four Woody Species. FRONTIERS IN PLANT SCIENCE 2020; 11:585674. [PMID: 33329647 PMCID: PMC7732674 DOI: 10.3389/fpls.2020.585674] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/03/2020] [Indexed: 05/08/2023]
Abstract
Plants may maintain long-term xylem function via efficiency-safety tradeoff and segmentation. Most studies focus on the growing season and community level. We studied species with different efficiency-safety tradeoff strategies, Quercus acutissima, Robinia pseudoacacia, Vitex negundo var. heterophylla, and Rhus typhina, to determine the seasonality of this mechanism. We separated their branches into perennial shoots and terminal twigs and monitored their midday water potential (Ψmd), relative water content (RWC), stem-specific hydraulic conductivity (Ks), loss of 12, 50, and 88% of maximum efficiency (i.e., P12, P50, P88) for 2 years. There were no correlations between water relations (Ψmd, RWC, Ks) and embolism resistance traits (P12, P50, P88) but they significantly differed between the perennial shoots and terminal twigs. All species had weak annual hydraulic efficiency-safety tradeoff but strong segmentation between the perennial shoots and the terminal twigs. R. pseudoacacia used a high-efficiency, low-safety strategy, whereas R. typhina used a high-safety, low-efficiency strategy. Q. acutissima and V. negundo var. heterophylla alternated these strategies. This mechanism provides a potential basis for habitat partitioning and niche divergence in the changing warm temperate zone environment.
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Affiliation(s)
- Xiao Liu
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Qiang Li
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Feng Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Xiaohan Sun
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Huijia Song
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Rong Cui
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Pan Wu
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Du
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Hui Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- *Correspondence: Hui Wang,
| | - Renqing Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
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34
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Pratt RB, Castro V, Fickle JC, Jacobsen AL. Embolism resistance of different aged stems of a California oak species (Quercus douglasii): optical and microCT methods differ from the benchtop-dehydration standard. TREE PHYSIOLOGY 2020; 40:5-18. [PMID: 31553460 DOI: 10.1093/treephys/tpz092] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 07/30/2019] [Accepted: 08/15/2019] [Indexed: 06/10/2023]
Abstract
Vulnerability of xylem to embolism is an important trait related to drought resistance of plants. Methods continue to be developed and debated for measuring embolism. We tested three methods (benchtop dehydration/hydraulic, micro-computed tomography (microCT) and optical) for assessing the vulnerability to embolism of a native California oak species (Quercus douglasii Hook. & Arn.), including an analysis of three different stem ages. All three methods were found to significantly differ in their estimates, with a greater resistance to embolism as follows: microCT > optical > hydraulic. Careful testing was conducted for the hydraulic method to evaluate multiple known potential artifacts, and none was found. One-year-old stems were more resistant than older stems using microCT and optical methods, but not hydraulic methods. Divergence between the microCT and optical methods from the standard hydraulic method was consistent with predictions based on known errors when estimating theoretical losses in hydraulic function in both microCT and optical methods. When the goal of a study is to describe or predict losses in hydraulic conductivity, neither the microCT nor optical methods are reliable for accurately constructing vulnerability curves of stems; nevertheless, these methods may be useful if the goal of a study is to identify embolism events irrespective of hydraulic conductivity or hydraulic function.
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Affiliation(s)
- R Brandon Pratt
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA
| | - Viridiana Castro
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA
| | - Jaycie C Fickle
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA
| | - Anna L Jacobsen
- Department of Biology, California State University, Bakersfield, 9001 Stockdale Hwy, Bakersfield, CA
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35
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McDowell NG, Brodribb TJ, Nardini A. Hydraulics in the 21 st century. THE NEW PHYTOLOGIST 2019; 224:537-542. [PMID: 31545889 DOI: 10.1111/nph.16151] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
| | - Timothy J Brodribb
- School of Biological Science, University of Tasmania, Hobart, TAS, Australia
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Trieste, Italy
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36
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Venturas MD, Pratt RB, Jacobsen AL, Castro V, Fickle JC, Hacke UG. Direct comparison of four methods to construct xylem vulnerability curves: Differences among techniques are linked to vessel network characteristics. PLANT, CELL & ENVIRONMENT 2019; 42:2422-2436. [PMID: 30997689 DOI: 10.1111/pce.13565] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/12/2019] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
During periods of dehydration, water transport through xylem conduits can become blocked by embolism formation. Xylem embolism compromises water supply to leaves and may lead to losses in productivity or plant death. Vulnerability curves (VCs) characterize plant losses in conductivity as xylem pressures decrease. VCs are widely used to characterize and predict plant water use at different levels of water availability. Several methodologies for constructing VCs exist and sometimes produce different results for the same plant material. We directly compared four VC construction methods on stems of black cottonwood (Populus trichocarpa), a model tree species: dehydration, centrifuge, X-ray-computed microtomography (microCT), and optical. MicroCT VC was the most resistant, dehydration and centrifuge VCs were intermediate, and optical VC was the most vulnerable. Differences among VCs were not associated with how cavitation was induced but were related to how losses in conductivity were evaluated: measured hydraulically (dehydration and centrifuge) versus evaluated from visual information (microCT and optical). Understanding how and why methods differ in estimating vulnerability to xylem embolism is important for advancing knowledge in plant ecophysiology, interpreting literature data, and using accurate VCs in water flux models for predicting plant responses to drought.
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Affiliation(s)
- Martin D Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, 84112, Utah, USA
| | - R Brandon Pratt
- Department of Biology, California State University Bakersfield, Bakersfield, 93311, California, USA
| | - Anna L Jacobsen
- Department of Biology, California State University Bakersfield, Bakersfield, 93311, California, USA
| | - Viridiana Castro
- Department of Biology, California State University Bakersfield, Bakersfield, 93311, California, USA
| | - Jaycie C Fickle
- Department of Biology, California State University Bakersfield, Bakersfield, 93311, California, USA
| | - Uwe G Hacke
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
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