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Bouzaouia S, Ryckewaert M, Héran D, Ducanchez A, Bendoula R. Using Dynamic Laser Speckle Imaging for Plant Breeding: A Case Study of Water Stress in Sunflowers. SENSORS (BASEL, SWITZERLAND) 2024; 24:5260. [PMID: 39204955 PMCID: PMC11360077 DOI: 10.3390/s24165260] [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: 07/02/2024] [Revised: 07/29/2024] [Accepted: 08/09/2024] [Indexed: 09/04/2024]
Abstract
This study focuses on the promising use of biospeckle technology to detect water stress in plants, a complex physiological mechanism. This involves monitoring the temporal activity of biospeckle pattern to study the occurrence of stress within the leaf. The effects of water stress in plants can involve physical and biochemical changes. Some of these changes may alter the optical scattering properties of leaves. The present study therefore proposes to test the potential of a biospeckle measurement to observe the temporal evolution in different varieties of sunflower plants under water stress. An experiment applying controlled water stress with osmotic shock using polyethylene glycol 6000 (PEG) was conducted on two sunflower varieties: one sensitive, and the other more tolerant to water stress. Temporal monitoring of biospeckle activity in these plants was performed using the average value of difference (AVD) indicator. Results indicate that AVD highlights the difference in biospeckle activity between day and night, with lower activity at night for both varieties. The addition of PEG entailed a gradual decrease in values throughout the experiment, particularly for the sensitive variety. The results obtained are consistent with the behaviour of the varieties submitted to water stress. Indeed, a few days after the introduction of PEG, a stronger decrease in AVD indicator values was observed for the sensitive variety than for the resistant variety. This study highlights the dynamics of biospeckle activity for different sunflower varieties undergoing water stress and can be considered as a promising phenotyping tool.
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Affiliation(s)
- Sherif Bouzaouia
- ITAP, INRAE, Institut Agro, University of Montpellier, 34060 Montpellier, France; (D.H.); (A.D.); (R.B.)
| | - Maxime Ryckewaert
- (LIRMM) Laboratory of Computer Science, Robotics and Microelectronics of Montpellier, Inria, (CNRS) National Center for Scientific Research, University of Montpellier, 34392 Montpellier, France;
| | - Daphné Héran
- ITAP, INRAE, Institut Agro, University of Montpellier, 34060 Montpellier, France; (D.H.); (A.D.); (R.B.)
| | - Arnaud Ducanchez
- ITAP, INRAE, Institut Agro, University of Montpellier, 34060 Montpellier, France; (D.H.); (A.D.); (R.B.)
| | - Ryad Bendoula
- ITAP, INRAE, Institut Agro, University of Montpellier, 34060 Montpellier, France; (D.H.); (A.D.); (R.B.)
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Nardini A, Cochard H, Mayr S. Talk is cheap: rediscovering sounds made by plants. TRENDS IN PLANT SCIENCE 2024; 29:662-667. [PMID: 38218649 DOI: 10.1016/j.tplants.2023.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/21/2023] [Accepted: 11/30/2023] [Indexed: 01/15/2024]
Abstract
A recent study and related commentaries have raised new interest in the phenomenon of ultrasonic sound production by plants exposed to stress, especially drought. While recent technological advancements have allowed the demonstration that these sounds can propagate in the air surrounding plants, we remind readers here that research on sound production by plants is more than 100 years old. The mechanisms and patterns of sound emission from plants subjected to different stress factors are also reasonably understood, thanks to the pioneering work of John Milburn and others. By contrast, experimental evidence for a role of these sounds in plant-animal or plant-plant communication remains lacking and, at present, these ideas remain highly speculative.
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Affiliation(s)
- Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy.
| | - Hervé Cochard
- Université Clermont-Auvergne, INRAE, PIAF, Clermont-Ferrand 63000, France
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, 6020 Innsbruck, Austria
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3
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Xu M, Li K, Xue Y, Wang F, Liu Z, Xiao T. Measurement of mass force field driving water refilling of cuttage. Sci Rep 2024; 14:8947. [PMID: 38637680 PMCID: PMC11026483 DOI: 10.1038/s41598-024-59716-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 04/15/2024] [Indexed: 04/20/2024] Open
Abstract
Cuttage is a common plant cultivation method, and the key to its survival is the restoration of water refilling, which remains unclear up to now. We report 3D dynamic imaging of water refilling of cuttage without resorting to any contrast agent. Hydrodynamics of the refilled water flow over time reveals the existence of a unit mass force field with a gradient along the refilling direction, which means that cutting plants also have a gradient force field to drive the recovery of water refilling, as predicted by Cohesion-Tension theory in normal plants. We found that force fields of different functional regions are isolated and independently distributed, which is conducive to ensure the safety of water transmission. At the same time, we also found that there is a so-called "inchworm effect" in the mass force field, which contributes to the force transfer inside the cutting through local force accumulation. Results of this paper demonstrate that the developed method for the measurement of mass force field in-vivo is applicable to help decipher the mechanism of plant water refilling.
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Affiliation(s)
- Mingwei Xu
- Research Center for Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ke Li
- Research Center for Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Yanling Xue
- Research Center for Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Feixiang Wang
- Research Center for Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Zhixuan Liu
- Hunan Rice Research Institute, Hunan Academy of Agricultural Sciences, Changsha, 410125, China
| | - Tiqiao Xiao
- Research Center for Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China.
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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4
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Tonet V, Brodribb T, Bourbia I. Variation in xylem vulnerability to cavitation shapes the photosynthetic legacy of drought. PLANT, CELL & ENVIRONMENT 2024; 47:1160-1170. [PMID: 38108586 DOI: 10.1111/pce.14788] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 11/08/2023] [Accepted: 12/01/2023] [Indexed: 12/19/2023]
Abstract
Increased drought conditions impact tree health, negatively disrupting plant water transport which, in turn, affects plant growth and survival. Persistent drought legacy effects have been documented in many diverse ecosystems, yet we still lack a mechanistic understanding of the physiological processes limiting tree recovery after drought. Tackling this question, we exposed saplings of a common Australian evergreen tree (Eucalyptus viminalis) to a cycle of drought and rewatering, seeking evidence for a link between the spread of xylem cavitation within the crown and the degree of photosynthetic recovery postdrought. Individual leaves experiencing >35% vein cavitation quickly died but this did not translate to a rapid overall canopy damage. Rather, whole canopies showed a gradual decline in mean postdrought gas exchange rates as water stress increased. This gradual loss of canopy function postdrought was due to a significant variation in cavitation vulnerability of leaves within canopies leading to diversity in the capacity of leaves within a single crown to recover function after drought. These results from the evergreen E. viminalis emphasise the importance of within-crown variation in xylem vulnerability as a central character regulating the dynamics of canopy death and the severity of drought legacy through time.
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Affiliation(s)
- Vanessa Tonet
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
- School of Forestry & Environmental Studies, Yale University, New Haven, Connecticut, USA
| | - Timothy Brodribb
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
| | - Ibrahim Bourbia
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
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Sáez PL, Vallejos V, Sancho-Knapik D, Cavieres LA, Ramírez CF, Bravo LA, Javier Peguero-Pina J, Gil-Pelegrín E, Galmés J. Leaf hydraulic properties of Antarctic plants: effects of growth temperature and its coordination with photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:2013-2026. [PMID: 38173309 DOI: 10.1093/jxb/erad474] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 01/02/2024] [Indexed: 01/05/2024]
Abstract
One of the well-documented effects of regional warming in Antarctica is the impact on flora. Warmer conditions modify several leaf anatomical traits of Antarctic vascular plants, increasing photosynthesis and growth. Given that CO2 and water vapor partially share their diffusion pathways through the leaf, changes in leaf anatomy could also affect the hydraulic traits of Antarctic plants. We evaluated the effects of growth temperature on several anatomical and hydraulic parameters of Antarctic plants and assessed the trait co-variation between these parameters and photosynthetic performance. Warmer conditions promoted an increase in leaf and whole plant hydraulic conductivity, correlating with adjustments in carbon assimilation. These adjustments were consistent with changes in leaf vasculature, where Antarctic species displayed different strategies. At higher temperature, Colobanthus quitensis decreased the number of leaf xylem vessels, but increased their diameter. In contrast, in Deschampsia antarctica the diameter did not change, but the number of vessels increased. Despite this contrasting behavior, some traits such as a small leaf diameter of vessels and a high cell wall rigidity were maintained in both species, suggesting a water-conservation response associated with the ability of Antarctic plants to cope with harsh environments.
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Affiliation(s)
- Patricia L Sáez
- Laboratorio de Fisiología y Biología Molecular Vegetal, Instituto de Agroindustria, Departamento de Ciencias Agronómicas y Recursos Naturales, Facultad de Ciencias Agropecuarias y Medioambiente, Universidad de La Frontera, Temuco, Chile
- Instituto de Ecología y Biodiversidad-IEB, Concepción, Chile
| | - Valentina Vallejos
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, y Facultad de Ciencias Forestales, Universidad de Concepción, Concepción, Chile
| | - Domingo Sancho-Knapik
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, Zaragoza, España
| | - Lohengrin A Cavieres
- Instituto de Ecología y Biodiversidad-IEB, Concepción, Chile
- ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Barrio Universitario s/n, Concepción, Chile
| | - Constanza F Ramírez
- Laboratorio Cultivo de Tejidos Vegetales, Centro de Biotecnología, y Facultad de Ciencias Forestales, Universidad de Concepción, Concepción, Chile
| | - León A Bravo
- Laboratorio de Fisiología y Biología Molecular Vegetal, Instituto de Agroindustria, Departamento de Ciencias Agronómicas y Recursos Naturales, Facultad de Ciencias Agropecuarias y Medioambiente, Universidad de La Frontera, Temuco, Chile
| | - José Javier Peguero-Pina
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, Zaragoza, España
| | - Eustaquio Gil-Pelegrín
- Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, Zaragoza, España
| | - Jeroni Galmés
- Research Group on Plant Biology under Mediterranean Conditions, INAGEA-Universitat de les Illes Balears, Palma de Mallorca, Balearic Islands, Spain
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Zhang X, Ma S, Hu H, Li F, Bao W, Huang L. A trade-off between leaf hydraulic efficiency and safety across three xerophytic species in response to increased rock fragment content. TREE PHYSIOLOGY 2024; 44:tpae010. [PMID: 38245807 PMCID: PMC10918055 DOI: 10.1093/treephys/tpae010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 01/05/2024] [Accepted: 01/14/2024] [Indexed: 01/22/2024]
Abstract
Limited information is available on the variation of plant leaf hydraulic traits in relation to soil rock fragment content (RFC), particularly for xerophytes native to rocky mountain areas. In this study, we conducted a field experiment with four gradients of RFC (0, 25, 50 and 75% ν ν-1) on three different xerophytic species (Sophora davidii, Cotinus szechuanensis and Bauhinia brachycarpa). We measured predawn and midday leaf water potential (Ψleaf), leaf hydraulic conductance (Kleaf), Ψleaf induced 50% loss of Kleaf (P50), pressure-volume curve traits and leaf structure. A consistent response of hydraulic traits to increased RFC was observed in three species. Kleaf showed a decrease, whereas P50 and turgor loss point (Ψtlp) became increasingly negative with increasing RFC. Thus, a clear trade-off between hydraulic efficiency and safety was observed in the xerophytic species. In all three species, the reduction in Kleaf was associated with an increase in leaf mass per area. In S. davidii, alterations in Kleaf and P50 were driven by leaf vein density (VLA) and Ψtlp. In C. szechuanensis, Ψtlp and VLA drove the changes in Kleaf and P50, respectively. In B. brachycarpa, changes in P50 were driven by VLA, whereas changes in both Kleaf and P50 were simultaneously influenced by Ψtlp. Our findings suggest that adaptation to increased rockiness necessarily implies a trade-off between leaf hydraulic efficiency and safety in xerophytic species. Additionally, the trade-off between leaf hydraulic efficiency and safety among xerophytic species is likely to result from processes occurring in the xylem and the outside-xylem hydraulic pathways. These findings contribute to a better understanding of the survival strategies and mechanisms of xerophytes in rocky soils, and provide a theoretical basis for the persistence of xerophytic species in areas with stony substrates.
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Affiliation(s)
- Xiulong Zhang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
| | - Shaowei Ma
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Hui Hu
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Fanglan Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
| | - Weikai Bao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
| | - Long Huang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4 South Renmin Road, Wuhou District, Chengdu, Sichuan 610041, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Shijingshan District, Beijing 100049, China
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7
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Grunwald Y, Yaaran A, Moshelion M. Illuminating plant water dynamics: the role of light in leaf hydraulic regulation. THE NEW PHYTOLOGIST 2024; 241:1404-1414. [PMID: 38155452 DOI: 10.1111/nph.19497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/25/2023] [Indexed: 12/30/2023]
Abstract
Light intensity and quality influence photosynthesis directly but also have an indirect effect by increasing stomatal apertures and enhancing gas exchange. Consequently, in areas such as the upper canopy, a high water demand for transpiration and temperature regulation is created. This paper explores how light intensity and the natural high Blue-Light (BL) : Red-Light (RL) ratio in these areas, is important for controlling leaf hydraulic conductance (Kleaf ) by BL signal transduction, increasing water permeability in cells surrounding the vascular tissue, in supporting the enormous water demands. Conversely, shaded inner-canopy areas receive less radiation, have lower water and cooling demands, and exhibit reduced Kleaf due to diminished intensity and BL induction. Intriguingly, shaded leaves display higher water-use efficiency (compared with upper-canopy) due to decreased transpiration and cooling requirements while the presence of RL supports photosynthesis.
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Affiliation(s)
- Yael Grunwald
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
- The Plant & Environmental Sciences Department, Weizmann Institute of Science, Rehovot, 7632706, Israel
| | - Adi Yaaran
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Menachem Moshelion
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 7610001, Israel
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Wang X, Huang J, Peng S, Xiong D. Leaf rolling precedes stomatal closure in rice (Oryza sativa) under drought conditions. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:6650-6661. [PMID: 37551729 DOI: 10.1093/jxb/erad316] [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: 12/31/2022] [Accepted: 08/05/2023] [Indexed: 08/09/2023]
Abstract
Leaf rolling is a physiological response to drought that may help to reduce water loss, but its significance as a contribution to drought tolerance is uncertain. We scored the leaf rolling of four rice genotypes along an experimental drought gradient using an improved cryo-microscopy method. Leaf water potential (Ψleaf), gas exchange, chlorophyll fluorescence, leaf hydraulic conductance, rehydration capacity, and the bulk turgor loss point were also analysed. During the drought process, stomatal conductance declined sharply to reduce water loss, and leaves rolled up before the stomata completely closed. The leaf water loss rate of rolled leaves was significantly reduced compared with artificially flattened leaves. The Ψleaf threshold of initial leaf rolling ranged from -1.95 to -1.04 MPa across genotypes. When a leaf rolled so that the leaf edges were touching, photosynthetic rate and stomatal conductance declined more than 80%. Across genotypes, leaf hydraulic conductance declined first, followed by gas exchange and chlorophyll fluorescence parameters. However, the Ψleaf threshold for a given functional trait decline differed significantly among genotypes, with the exception of leaf hydraulic conductance. Our results suggested that leaf rolling was mechanistically linked to drought avoidance and tolerance traits and might serve as a useful phenotypic trait for rice breeding in future drought scenarios.
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Affiliation(s)
- Xiaoxiao Wang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Jianliang Huang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Shaobing Peng
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Dongliang Xiong
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
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9
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Petruzzellis F, Di Bonaventura A, Tordoni E, Tomasella M, Natale S, Trifilò P, Tromba G, Di Lillo F, D'Amico L, Bacaro G, Nardini A. The optical method based on gas injection overestimates leaf vulnerability to xylem embolism in three woody species. TREE PHYSIOLOGY 2023; 43:1784-1795. [PMID: 37427987 DOI: 10.1093/treephys/tpad088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/26/2023] [Accepted: 07/04/2023] [Indexed: 07/11/2023]
Abstract
Plant hydraulic traits related to leaf drought tolerance, like the water potential at turgor loss point (TLP) and the water potential inducing 50% loss of hydraulic conductance (P50), are extremely useful to predict the potential impacts of drought on plants. While novel techniques have allowed the inclusion of TLP in studies targeting a large group of species, fast and reliable protocols to measure leaf P50 are still lacking. Recently, the optical method coupled with the gas injection (GI) technique has been proposed as a possibility to speed up the P50 estimation. Here, we present a comparison of leaf optical vulnerability curves (OVcs) measured in three woody species, namely Acer campestre (Ac), Ostrya carpinifolia (Oc) and Populus nigra (Pn), based on bench dehydration (BD) or GI of detached branches. For Pn, we also compared optical data with direct micro-computed tomography (micro-CT) imaging in both intact saplings and cut shoots subjected to BD. Based on the BD procedure, Ac, Oc and Pn had P50 values of -2.87, -2.47 and -2.11 MPa, respectively, while the GI procedure overestimated the leaf vulnerability (-2.68, -2.04 and -1.54 MPa for Ac, Oc and Pn, respectively). The overestimation was higher for Oc and Pn than for Ac, likely reflecting the species-specific vessel lengths. According to micro-CT observations performed on Pn, the leaf midrib showed none or very few embolized conduits at -1.2 MPa, consistent with the OVcs obtained with the BD procedure but at odds with that derived on the basis of GI. Overall, our data suggest that coupling the optical method with GI might not be a reliable technique to quantify leaf hydraulic vulnerability since it could be affected by the 'open-vessel' artifact. Accurate detection of xylem embolism in the leaf vein network should be based on BD, preferably of intact up-rooted plants.
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Affiliation(s)
- Francesco Petruzzellis
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Azzurra Di Bonaventura
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Viale delle Scienze 206, Udine 33100, Italy
| | - Enrico Tordoni
- Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, J. Liivi 2, Tartu 50409, Estonia
| | - Martina Tomasella
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Sara Natale
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Patrizia Trifilò
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, Messina 98166, Italy
| | - Giuliana Tromba
- Elettra Sincrotrone Trieste, Area Science Park, Basovizza, Trieste 34149, Italy
| | - Francesca Di Lillo
- Elettra Sincrotrone Trieste, Area Science Park, Basovizza, Trieste 34149, Italy
| | - Lorenzo D'Amico
- Elettra Sincrotrone Trieste, Area Science Park, Basovizza, Trieste 34149, Italy
- Department of Physics, University of Trieste, Via A. Valerio 2, Trieste 34127, Italy
| | - Giovanni Bacaro
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
| | - Andrea Nardini
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, Trieste 34127, Italy
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10
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Álvarez-Maldini C, Acevedo M, Estay D, Aros F, Dumroese RK, Sandoval S, Pinto M. Examining physiological, water relations, and hydraulic vulnerability traits to determine anisohydric and isohydric behavior in almond ( Prunus dulcis) cultivars: Implications for selecting agronomic cultivars under changing climate. FRONTIERS IN PLANT SCIENCE 2022; 13:974050. [PMID: 36092408 PMCID: PMC9453546 DOI: 10.3389/fpls.2022.974050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
The search for drought tolerant species or cultivars is important to address water scarcity caused by climate change in Mediterranean regions. The anisohydric-isohydric behavior concept has been widely used to describe stomatal regulation during drought, simply in terms of variation of minimal water potential (Ψmin) in relation to pre-dawn water potential (Ψpd). However, its simplicity has sometimes failed to deliver consistent results in describing a complex behavior that results from the coordination of several plant functional traits. While Prunus dulcis (almond) is known as a drought tolerant species, little information is available regarding consistent metrics to discriminate among cultivars or the mechanisms underlying drought tolerance in almond. Here we show a sequence of plant stomatal, hydraulic, and wilting responses to drought in almonds, and the main differences between anisohydric and isohydric cultivars. In a pot desiccation experiment we observed that stomatal closure in P. dulcis is not driven by loss in turgor or onset of xylem cavitation, but instead, occurs early in response to decreasing Ψmin that could be related to the protection of the integrity of the hydraulic system, independently of cultivar. Also, we report that anisohydric cultivars of P. dulcis are characterized by maximum stomatal conductance, lower water potentials for stomatal closure and turgor loss, and lower vulnerability to xylem cavitation, which are traits that correlated with metrics to discriminate anisohydric and isohydric behavior. Our results demonstrate that P. dulcis presents a strategy to avoid cavitation by closing stomata during the early stages of drought. Future research should also focus on below-ground hydraulic traits, which could trigger stomatal closure in almond.
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Affiliation(s)
- Carolina Álvarez-Maldini
- Instituto Ciencias Agroalimentarias Animales y Ambientales (ICA3), Campus Colchagua, Universidad de O′Higgins, San Fernando, Chile
| | - Manuel Acevedo
- Centro Tecnológico de la Planta Forestal, Instituto Forestal, Sede Biobío, San Pedro de la Paz, Chile
| | - Daniela Estay
- Instituto Ciencias Agroalimentarias Animales y Ambientales (ICA3), Campus Colchagua, Universidad de O′Higgins, San Fernando, Chile
| | - Fabián Aros
- Instituto Ciencias Agroalimentarias Animales y Ambientales (ICA3), Campus Colchagua, Universidad de O′Higgins, San Fernando, Chile
| | - R. Kasten Dumroese
- United States Department of Agriculture Forest Service, Rocky Mountain Research Station, Moscow, ID, United States
| | - Simón Sandoval
- Laboratorio de Análisis y Modelamiento de Geoinformación, Departamento de Manejo de Bosques y Medio Ambiente, Facultad de Ciencias Forestales, Universidad de Concepción, Concepción, Chile
| | - Manuel Pinto
- Instituto Ciencias Agroalimentarias Animales y Ambientales (ICA3), Campus Colchagua, Universidad de O′Higgins, San Fernando, Chile
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11
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Jacob V, Choat B, Churchill AC, Zhang H, Barton CVM, Krishnananthaselvan A, Post AK, Power SA, Medlyn BE, Tissue DT. High safety margins to drought-induced hydraulic failure found in five pasture grasses. PLANT, CELL & ENVIRONMENT 2022; 45:1631-1646. [PMID: 35319101 DOI: 10.1111/pce.14318] [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: 11/12/2021] [Revised: 02/13/2022] [Accepted: 03/16/2022] [Indexed: 06/14/2023]
Abstract
Determining the relationship between reductions in stomatal conductance (gs ) and leaf water transport during dehydration is key to understanding plant drought responses. While numerous studies have analysed the hydraulic function of woody species, minimal research has been conducted on grasses. Here, we sought to characterize hydraulic vulnerability in five widely-occurring pasture grasses (including both C3 and C4 grasses) and determine whether reductions in gs and leaf hydraulic conductance (Kleaf ) during dehydration could be attributed to xylem embolism. Using the optical vulnerability (OV) technique, we found that all species were highly resistant to xylem embolism when compared to other herbaceous angiosperms, with 50% xylem embolism (PX50 ) occurring at xylem pressures ranging from -4.4 to -6.1 MPa. We observed similar reductions in gs and Kleaf under mild water stress for all species, occurring well before PX50 . The onset of xylem embolism (PX12 ) occurred consistently after stomatal closure and 90% reduction of Kleaf . Our results suggest that factors other than xylem embolism are responsible for the majority of reductions in gs and Kleaf during drought and reductions in the productivity of pasture species under moderate drought may not be driven by embolism.
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Affiliation(s)
- Vinod Jacob
- Western Sydney University, Penrith, New South Wales, Australia
| | - Brendan Choat
- Western Sydney University, Penrith, New South Wales, Australia
| | | | - Haiyang Zhang
- Western Sydney University, Penrith, New South Wales, Australia
| | | | | | - Alison K Post
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Sally A Power
- Western Sydney University, Penrith, New South Wales, Australia
| | | | - David T Tissue
- Western Sydney University, Penrith, New South Wales, Australia
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12
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Shi P, Miao Q, Niinemets Ü, Liu M, Li Y, Yu K, Niklas KJ. Scaling relationships of leaf vein and areole traits versus leaf size for nine Magnoliaceae species differing in venation density. AMERICAN JOURNAL OF BOTANY 2022; 109:899-909. [PMID: 35471633 DOI: 10.5061/dryad.8cz8w9gsv] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 05/21/2023]
Abstract
PREMISE Across species, main leaf vein density scales inversely with leaf area (A). Yet, minor vein density manifests no clear relationship with respect to A, despite having the potential to provide important insights into the trade-off among the investments in leaf mechanical support, hydraulics, and light interception. METHODS To examine this phenomenon, the leaves of nine Magnoliaceae leaves were sampled, and the scaling relationships among A and midrib length (ML), total vein length (TVL), total vein area (TVA), total areole area (TAA), and mean areole area (MAA) were determined. The scaling relationships between MAA and areole density (the number of areoles per unit leaf area) and between MAA and A were also analyzed. RESULTS For five of the nine species, A was proportional to ML2 . For eight of the nine species, TVL and TVA were both proportional to A. The numerical values of the scaling exponents for TAA vs. A were between 1.0 and 1.07 for eight species; i.e., as expected, TAA was isometrically proportional to A. There was no correlation between MAA and A, but MAA scaled inversely with respect to areole density for each species. CONCLUSIONS The correlation between midrib "density" (i.e., ML/A) and A, and the lack of correlation between total leaf vein density and A result from the A ∝$\propto $ ML2 scaling relationship and the proportional relationship between TVL and A, respectively. Leaves with the same size can have widely varying MAA. Thus, leaf size itself does not directly constrain leaf hydraulic efficiency and redundancy.
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Affiliation(s)
- Peijian Shi
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Qinyue Miao
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Ülo Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, 51006, Estonia
- Estonian Academy of Sciences, Tallinn, 10130, Estonia
| | - Mengdi Liu
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Yirong Li
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Kexin Yu
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Karl J Niklas
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
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13
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Shi P, Miao Q, Niinemets Ü, Liu M, Li Y, Yu K, Niklas KJ. Scaling relationships of leaf vein and areole traits versus leaf size for nine Magnoliaceae species differing in venation density. AMERICAN JOURNAL OF BOTANY 2022; 109:899-909. [PMID: 35471633 PMCID: PMC9327518 DOI: 10.1002/ajb2.1856] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 05/05/2023]
Abstract
PREMISE Across species, main leaf vein density scales inversely with leaf area (A). Yet, minor vein density manifests no clear relationship with respect to A, despite having the potential to provide important insights into the trade-off among the investments in leaf mechanical support, hydraulics, and light interception. METHODS To examine this phenomenon, the leaves of nine Magnoliaceae leaves were sampled, and the scaling relationships among A and midrib length (ML), total vein length (TVL), total vein area (TVA), total areole area (TAA), and mean areole area (MAA) were determined. The scaling relationships between MAA and areole density (the number of areoles per unit leaf area) and between MAA and A were also analyzed. RESULTS For five of the nine species, A was proportional to ML2 . For eight of the nine species, TVL and TVA were both proportional to A. The numerical values of the scaling exponents for TAA vs. A were between 1.0 and 1.07 for eight species; i.e., as expected, TAA was isometrically proportional to A. There was no correlation between MAA and A, but MAA scaled inversely with respect to areole density for each species. CONCLUSIONS The correlation between midrib "density" (i.e., ML/A) and A, and the lack of correlation between total leaf vein density and A result from the A ∝$\propto $ ML2 scaling relationship and the proportional relationship between TVL and A, respectively. Leaves with the same size can have widely varying MAA. Thus, leaf size itself does not directly constrain leaf hydraulic efficiency and redundancy.
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Affiliation(s)
- Peijian Shi
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry UniversityNanjing210037China
| | - Qinyue Miao
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry UniversityNanjing210037China
| | - Ülo Niinemets
- Institute of Agricultural and Environmental SciencesEstonian University of Life SciencesTartu51006Estonia
- Estonian Academy of SciencesTallinn10130Estonia
| | - Mengdi Liu
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry UniversityNanjing210037China
| | - Yirong Li
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry UniversityNanjing210037China
| | - Kexin Yu
- Bamboo Research Institute, College of Biology and the Environment, Nanjing Forestry UniversityNanjing210037China
| | - Karl J. Niklas
- School of Integrative Plant ScienceCornell UniversityIthacaNY14853USA
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14
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Wang X, Zhao J, Huang J, Peng S, Xiong D. Evaporative flux method of leaf hydraulic conductance estimation: sources of uncertainty and reporting format recommendation. PLANT METHODS 2022; 18:63. [PMID: 35549958 PMCID: PMC9097237 DOI: 10.1186/s13007-022-00888-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 04/08/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The accurate estimation of leaf hydraulic conductance (Kleaf) is important for revealing leaf physiological characteristics and function. However, the Kleaf values are largely incomparable in previous studies for a given species indicating some uncertain influencing factors in Kleaf measurement. RESULT We investigated the potential impacts of plant sampling method, measurement setup, environmental factors, and transpiration steady state identification on Kleaf estimation in Oryza sativa and Cinnamomum camphora using evaporation flux method (EFM). The effects of sampling and rehydration time, the small gravity pressure gradients between water sources and leaves, and water degassing on Kleaf estimation were negligible. As expected, the estimated steady flow rate (E) was significantly affected by multiple environmental factors including airflow around leaf, photosynthetically active radiation (PARa) on leaf surfaces and air temperature. Kleaf decreased by 40% when PARa declined from 1000 to 500 µmol m-2 s-1 and decreased by 15.1% when air temperature increased from 27 to 37 °C. In addition, accurate steady-state flow rate identification and leaf water potential measurement were important for Kleaf estimation. CONCLUSIONS Based on the analysis of influencing factors, we provided a format for reporting the metadata of EFM-based Kleaf to achieve greater comparability among studies and interpretation of differences.
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Affiliation(s)
- Xiaoxiao Wang
- National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Jinfang Zhao
- National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Jianliang Huang
- National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Shaobing Peng
- National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Dongliang Xiong
- National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
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15
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Song J, Trueba S, Yin XH, Cao KF, Brodribb TJ, Hao GY. Hydraulic vulnerability segmentation in compound-leaved trees: Evidence from an embolism visualization technique. PLANT PHYSIOLOGY 2022; 189:204-214. [PMID: 35099552 PMCID: PMC9070814 DOI: 10.1093/plphys/kiac034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/27/2021] [Indexed: 05/11/2023]
Abstract
The hydraulic vulnerability segmentation (HVS) hypothesis implies the existence of differences in embolism resistance between plant organs along the xylem pathway and has been suggested as an adaptation allowing the differential preservation of more resource-rich tissues during drought stress. Compound leaves in trees are considered a low-cost means of increasing leaf area and may thus be expected to show evidence of strong HVS, given the tendency of compound-leaved tree species to shed their leaf units during drought. However, the existence and role of HVS in compound-leaved tree species during drought remain uncertain. We used an optical visualization technique to estimate embolism occurrence in stems, petioles, and leaflets of shoots in two compound-leaved tree species, Manchurian ash (Fraxinus mandshurica) and Manchurian walnut (Juglans mandshurica). We found higher (less negative) water potentials corresponding to 50% loss of conductivity (P50) in leaflets and petioles than in stems in both species. Overall, we observed a consistent pattern of stem > petiole > leaflet in terms of xylem resistance to embolism and hydraulic safety margins (i.e. the difference between mid-day water potential and P50). The coordinated variation in embolism vulnerability between organs suggests that during drought conditions, trees benefit from early embolism and subsequent shedding of more expendable organs such as leaflets and petioles, as this provides a degree of protection to the integrity of the hydraulic system of the more carbon costly stems. Our results highlight the importance of HVS as an adaptive mechanism of compound-leaved trees to withstand drought stress.
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Affiliation(s)
- Jia Song
- CAS Key Laboratory of Forest Ecology and Management & Key Laboratory of Terrestrial Ecosystem Carbon Neutrality Liaoning Province, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China
- School of Environmental and Geographical Science, Shanghai Normal University, Shanghai 200234, China
- Yangtze River Delta National Observatory of Wetland Ecosystem, Shanghai Normal University, Shanghai 200234, China
| | - Santiago Trueba
- University of Bordeaux, INRAE, BIOGECO, 33615 Pessac, France
| | - Xiao-Han Yin
- CAS Key Laboratory of Forest Ecology and Management & Key Laboratory of Terrestrial Ecosystem Carbon Neutrality Liaoning Province, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China
| | - Kun-Fang Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, and College of Forestry, Guangxi University, Nanning, Guangxi 530004, China
| | - Timothy J Brodribb
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
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16
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Brodribb T, Brodersen CR, Carriqui M, Tonet V, Rodriguez Dominguez C, McAdam S. Linking xylem network failure with leaf tissue death. THE NEW PHYTOLOGIST 2021; 232:68-79. [PMID: 34164816 DOI: 10.1111/nph.17577] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
Global warming is expected to dramatically accelerate forest mortality as temperature and drought intensity increase. Predicting the magnitude of this impact urgently requires an understanding of the process connecting atmospheric drying to plant tissue damage. Recent episodes of forest mortality worldwide have been widely attributed to dry conditions causing acute damage to plant vascular systems. Under this scenario vascular embolisms produced by water stress are thought to cause plant death, yet this hypothetical trajectory has never been empirically demonstrated. Here we provide foundational evidence connecting failure in the vascular network of leaves with tissue damage caused during water stress. We observe a catastrophic sequence initiated by water column breakage under tension in leaf veins which severs local leaf tissue water supply, immediately causing acute cellular dehydration and irreversible damage. By highlighting the primacy of vascular network failure in the death of leaves exposed to drought or evaporative stress our results provide a strong mechanistic foundation upon which models of plant damage in response to dehydration can be confidently structured.
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Affiliation(s)
- Timothy Brodribb
- School of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania, 7001, Australia
| | - Craig R Brodersen
- School of the Environment, Yale University, New Haven, CT, 06511, USA
| | - Marc Carriqui
- School of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania, 7001, Australia
| | - Vanessa Tonet
- School of Biological Sciences, University of Tasmania, Sandy Bay, Tasmania, 7001, Australia
| | - Celia Rodriguez Dominguez
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avda. Reina Mercedes, 10, Sevilla, 41012, Spain
| | - Scott McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
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17
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Trifilò P, Petruzzellis F, Abate E, Nardini A. The extra-vascular water pathway regulates dynamic leaf hydraulic decline and recovery in Populus nigra. PHYSIOLOGIA PLANTARUM 2021; 172:29-40. [PMID: 33161600 DOI: 10.1111/ppl.13266] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/27/2020] [Accepted: 11/03/2020] [Indexed: 06/11/2023]
Abstract
Leaf hydraulic conductance (Kleaf ) is highly dynamic and typically responds to changes in water status and irradiance. However, the relative contribution of vascular (Kx ) and extra-vascular (Kox ) water pathways to Kleaf changes in response to water potential decline and recovery in function of light conditions remains poorly investigated. We investigated the dynamic responses of leaf hydraulics in Populus nigra L. by measuring Kleaf , Kx , and Kox changes under drought and upon recovery. Measurements were done at both low and high irradiance (LI and HI, respectively). Kleaf increased and became more vulnerable to dehydration under HI conditions than LI, due to marked changes of Kox . After re-watering, Kleaf recovered in parallel with Kox recovery, but Kleaf response to irradiance remained inhibited. Strong correlations between Kleaf and drought-induced membrane damage demonstrated the relevance of the cell-to-cell water pathway in driving the dynamic responses of Kleaf under drought and recovery. Our findings highlight the importance of coordination between water and light availability in modulating the overall Kleaf response to environmental conditions.
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Affiliation(s)
- Patrizia Trifilò
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Messina, Italy
| | | | - Elisa Abate
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Messina, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Trieste, Italy
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18
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Albuquerque C, Scoffoni C, Brodersen CR, Buckley TN, Sack L, McElrone AJ. Coordinated decline of leaf hydraulic and stomatal conductances under drought is not linked to leaf xylem embolism for different grapevine cultivars. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:7286-7300. [PMID: 33306796 DOI: 10.1093/jxb/eraa392] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
Drought decreases water transport capacity of leaves and limits gas exchange, which involves reduced leaf leaf hydraulic conductance (Kleaf) in both the xylem and outside-xylem pathways. Some literature suggests that grapevines are hyper-susceptible to drought-induced xylem embolism. We combined Kleaf and gas exchange measurements, micro-computed tomography of intact leaves, and spatially explicit modeling of the outside-xylem pathways to evaluate the role of vein embolism and Kleaf in the responses of two different grapevine cultivars to drought. Cabernet Sauvignon and Chardonnay exhibited similar vulnerabilities of Kleaf and gs to dehydration, decreasing substantially prior to leaf xylem embolism. Kleaf and gs decreased by 80% for both cultivars by Ψ leaf approximately -0.7 MPa and -1.2 MPa, respectively, while leaf xylem embolism initiated around Ψ leaf = -1.25 MPa in the midribs and little to no embolism was detected in minor veins even under severe dehydration for both cultivars. Modeling results indicated that reduced membrane permeability associated with a Casparian-like band in the leaf vein bundle sheath would explain declines in Kleaf of both cultivars. We conclude that during moderate water stress, changes in the outside-xylem pathways, rather than xylem embolism, are responsible for reduced Kleaf and gs. Understanding this mechanism could help to ensure adequate carbon capture and crop performance under drought.
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Affiliation(s)
- Caetano Albuquerque
- Department of Viticulture and Enology, University of California, Davis, 595 Hilgard Lane, Davis, CA, USA
| | - Christine Scoffoni
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA, USA
| | - Craig R Brodersen
- School of the Environment, Yale University, 195 Prospect Street, New Haven, CT, USA
| | - Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA, USA
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, USA
| | - Andrew J McElrone
- Department of Viticulture and Enology, University of California, Davis, 595 Hilgard Lane, Davis, CA, USA
- USDA-Agricultural Research Service, Davis, CA, USA
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19
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Brunetti C, Savi T, Nardini A, Loreto F, Gori A, Centritto M. Changes in abscisic acid content during and after drought are related to carbohydrate mobilization and hydraulic recovery in poplar stems. TREE PHYSIOLOGY 2020; 40:1043-1057. [PMID: 32186735 DOI: 10.1093/treephys/tpaa032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 02/26/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
Drought compromises plant's ability to replace transpired water vapor with water absorbed from the soil, leading to extensive xylem dysfunction and causing plant desiccation and death. Short-term plant responses to drought rely on stomatal closure, and on the plant's ability to recover hydraulic functioning after drought relief. We hypothesize a key role for abscisic acid (ABA) not only in the control of stomatal aperture, but also in hydraulic recovery. Young plants of Populus nigra L. were used to investigate possible relationships among ABA, non-structural carbohydrates (NSC) and xylem hydraulic function under drought and after re-watering. In Populus nigra L. plants subjected to drought, water transport efficiency and hydraulic recovery after re-watering were monitored by measuring the percentage loss of hydraulic conductivity (PLC) and stem specific hydraulic conductivity (Kstem). In the same plants ABA and NSC were quantified in wood and bark. Drought severely reduced stomatal conductance (gL) and markedly increased the PLC. Leaf and stem water potential, and stem hydraulic efficiency fully recovered within 24 h after re-watering, but gL values remained low. After re-watering, we found significant correlations between changes in ABA content and hexoses concentration both in wood and bark. Our findings suggest a role for ABA in the regulation of stem carbohydrate metabolism and starch mobilization upon drought relief, possibly promoting the restoration of xylem transport capacity.
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Affiliation(s)
- Cecilia Brunetti
- National Research Council of Italy, Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
| | - Tadeja Savi
- University of Natural Resources and Life Sciences, Institute of Botany, Department of Integrative Biology and Biodiversity Research, BOKU, Gregor-Mendel-Straße 33, 1190, Vienna, Austria Austria
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Francesco Loreto
- National Research Council of Italy, Department of Biology, Agriculture and Food Sciences, Piazzale Aldo Moro 7, 00185 Roma, Italy
| | - Antonella Gori
- Department of Agri-Food Production and Environmental Sciences, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino (Florence), Italy
| | - Mauro Centritto
- National Research Council of Italy, Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
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20
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Dayer S, Scharwies JD, Ramesh SA, Sullivan W, Doerflinger FC, Pagay V, Tyerman SD. Comparing Hydraulics Between Two Grapevine Cultivars Reveals Differences in Stomatal Regulation Under Water Stress and Exogenous ABA Applications. FRONTIERS IN PLANT SCIENCE 2020; 11:705. [PMID: 32636852 PMCID: PMC7316991 DOI: 10.3389/fpls.2020.00705] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 05/05/2020] [Indexed: 05/23/2023]
Abstract
Hydraulics of plants that have different strategies of stomatal regulation under water stress are relatively poorly understood. We explore how root and shoot hydraulics, stomatal conductance (g s), leaf and root aquaporin (AQP) expression, and abscisic acid (ABA) concentration in leaf xylem sap ([ABA]xylemsap) may be coordinated under mild water stress and exogenous ABA applications in two Vitis vinifera L. cultivars traditionally classified as near-isohydric (Grenache) and near-anisohydric (Syrah). Under water stress, Grenache exhibited stronger adjustments of plant and root hydraulic conductances and greater stomatal sensitivity to [ABA]xylemsap than Syrah resulting in greater conservation of soil moisture but not necessarily more isohydric behavior. Correlations between leaf (Ψleaf) and predawn (ΨPD) water potentials between cultivars suggested a "hydrodynamic" behavior rather than a particular iso-anisohydric classification. A significant decrease of Ψleaf in well-watered ABA-fed vines supported a role of ABA in the soil-leaf hydraulic pathway to regulate g s. Correlations between leaf and root AQPs expression levels under water deficit could explain the response of leaf (K leaf) and root (Lp r) hydraulic conductances in both cultivars. Additional studies under a wider range of soil water deficits are required to explore the possible differential regulation of g s and plant hydraulics in different cultivars and experimental conditions.
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Affiliation(s)
- Silvina Dayer
- School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia
| | - Johannes D. Scharwies
- School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia
| | - Sunita A. Ramesh
- School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia
| | - Wendy Sullivan
- School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia
| | | | - Vinay Pagay
- School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia
| | - Stephen D. Tyerman
- School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia
- Australian Research Council Centre of Excellence in Plant Energy Biology, Waite Research Institute, School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA, Australia
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21
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Creek D, Lamarque LJ, Torres-Ruiz JM, Parise C, Burlett R, Tissue DT, Delzon S. Xylem embolism in leaves does not occur with open stomata: evidence from direct observations using the optical visualization technique. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1151-1159. [PMID: 31641746 DOI: 10.1093/jxb/erz474] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
Drought represents a major abiotic constraint to plant growth and survival. On the one hand, plants keep stomata open for efficient carbon assimilation while, on the other hand, they close them to prevent permanent hydraulic impairment from xylem embolism. The order of occurrence of these two processes (stomatal closure and the onset of leaf embolism) during plant dehydration has remained controversial, largely due to methodological limitations. However, the newly developed optical visualization method now allows concurrent monitoring of stomatal behaviour and leaf embolism formation in intact plants. We used this new approach directly by dehydrating intact saplings of three contrasting tree species and indirectly by conducting a literature survey across a greater range of plant taxa. Our results indicate that increasing water stress generates the onset of leaf embolism consistently after stomatal closure, and that the lag time between these processes (i.e. the safety margin) rises with increasing embolism resistance. This suggests that during water stress, embolism-mediated declines in leaf hydraulic conductivity are unlikely to act as a signal for stomatal down-regulation. Instead, these species converge towards a strategy of closing stomata early to prevent water loss and delay catastrophic xylem dysfunction.
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Affiliation(s)
- Danielle Creek
- Université Clermont-Auvergne, INRA, PIAF, Clermont-Ferrand, France
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | | | | | | | - Regis Burlett
- BIOGECO, INRA, Université de Bordeaux, Pessac, France
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
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22
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Harayama H, Kitao M, Agathokleous E, Ishida A. Effects of major vein blockage and aquaporin inhibition on leaf hydraulics and stomatal conductance. Proc Biol Sci 2019; 286:20190799. [PMID: 31161902 PMCID: PMC6571453 DOI: 10.1098/rspb.2019.0799] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 05/08/2019] [Indexed: 01/25/2023] Open
Abstract
The density and architecture of leaf veins determine the network and efficiency of water transport within laminae and resultant leaf gas exchange and vary widely among plant species. Leaf hydraulic conductance ( Kleaf) can be regulated by vein architecture in conjunction with the water channel protein aquaporin. However, our understanding of how leaf veins and aquaporins affect leaf hydraulics and stomatal conductance ( gs) remains poor. By inducing blockage of the major veins and inhibition of aquaporin activity using HgCl2, we examined the effects of major veins and aquaporins on Kleaf and gs in species with different venation types. A vine species, with thick first-order veins and low vein density, displayed a rapidly declined gs with high leaf water potential in response to vein blockage and a greatly reduced Kleaf and gs in response to aquaporin inhibition, suggesting that leaf aquaporins are involved in isohydric/anisohydric stomatal behaviour. Across species, the decline in Kleaf and gs due to aquaporin inhibition increased linearly with decreasing major vein density, possibly indicating that a trade-off function between vein architecture (apoplastic pathway) and aquaporin activity (cell-to-cell pathway) affects leaf hydraulics.
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Affiliation(s)
- Hisanori Harayama
- Hokkaido Research Center, Forestry and Forest Products Research Institute, 7 Hitsujigaoka, Toyohira-Ku, Sapporo, Hokkaido 062-8516, Japan
| | - Mitsutoshi Kitao
- Hokkaido Research Center, Forestry and Forest Products Research Institute, 7 Hitsujigaoka, Toyohira-Ku, Sapporo, Hokkaido 062-8516, Japan
| | - Evgenios Agathokleous
- Hokkaido Research Center, Forestry and Forest Products Research Institute, 7 Hitsujigaoka, Toyohira-Ku, Sapporo, Hokkaido 062-8516, Japan
- Institute of Ecology, Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
| | - Atsushi Ishida
- Center for Ecological Research, Kyoto University, Otsu, Shiga 520-2113, Japan
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23
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Hernandez-Santana V, Diaz-Rueda P, Diaz-Espejo A, Raya-Sereno MD, Gutiérrez-Gordillo S, Montero A, Perez-Martin A, Colmenero-Flores JM, Rodriguez-Dominguez CM. Hydraulic Traits Emerge as Relevant Determinants of Growth Patterns in Wild Olive Genotypes Under Water Stress. FRONTIERS IN PLANT SCIENCE 2019; 10:291. [PMID: 30918509 PMCID: PMC6424893 DOI: 10.3389/fpls.2019.00291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/22/2019] [Indexed: 05/11/2023]
Abstract
The hydraulic traits of plants, or the efficiency of water transport throughout the plant hydraulic system, could help to anticipate the impact of climate change and improve crop productivity. However, the mechanisms explaining the role of hydraulic traits on plant photosynthesis and thus, plant growth and yield, are just beginning to emerge. We conducted an experiment to identify differences in growth patterns at leaf, root and whole plant level among four wild olive genotypes and to determine whether hydraulic traits may help to explain such differences through their effect on photosynthesis. We estimated the relative growth rate (RGR), and its components, leaf gas exchange and hydraulic traits both at the leaf and whole-plant level in the olive genotypes over a full year. Photosynthetic capacity parameters were also measured. We observed different responses to water stress in the RGRs of the genotypes studied being best explained by changes in the net CO2 assimilation rate (NAR). Further, net photosynthesis, closely related to NAR, was mainly determined by hydraulic traits, both at leaf and whole-plant levels. This was mediated through the effects of hydraulic traits on stomatal conductance. We observed a decrease in leaf area: sapwood area and leaf area: root area ratios in water-stressed plants, which was more evident in the olive genotype Olea europaea subsp. guanchica (GUA8), whose RGR was less affected by water deficit than the other olive genotypes. In addition, at the leaf level, GUA8 water-stressed plants presented a better photosynthetic capacity due to a higher mesophyll conductance to CO2 and a higher foliar N. We conclude that hydraulic allometry adjustments of whole plant and leaf physiological response were well coordinated, buffering the water stress experienced by GUA8 plants. In turn, this explained their higher relative growth rates compared to the rest of the genotypes under water-stress conditions.
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Affiliation(s)
- Virginia Hernandez-Santana
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Pablo Diaz-Rueda
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Antonio Diaz-Espejo
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - María D. Raya-Sereno
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
- School of Agricultural Engineering, CEIGRAM, Universidad Politécnica de Madrid, Madrid, Spain
| | - Saray Gutiérrez-Gordillo
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
- Centro “Las Torres-Tomejil”, Instituto Andaluz de Investigación y Formación Agraria y Pesquera, Seville, Spain
| | - Antonio Montero
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Alfonso Perez-Martin
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Jose M. Colmenero-Flores
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Celia M. Rodriguez-Dominguez
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
- School of Biological Sciences, University of Tasmania, Hobart, TAS, Australia
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24
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Vinya R, Malhi Y, Brown ND, Fisher JB, Brodribb T, Aragão LEOC. Seasonal changes in plant-water relations influence patterns of leaf display in Miombo woodlands: evidence of water conservative strategies. TREE PHYSIOLOGY 2019; 39:104-112. [PMID: 29920608 DOI: 10.1093/treephys/tpy062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 05/12/2018] [Indexed: 06/08/2023]
Abstract
Water availability has frequently been linked to seasonal leaf display in seasonally dry ecosystems, but there have been few ecohydrological investigations of this link. Miombo woodland is a dominant seasonally dry tropical forest ecosystem type in southern Africa; however, there are few data on the relationship between seasonal dynamics in plant-water relations and patterns of leaf display for Miombo woodland. Here we investigate this relationship among nine key Miombo woodland tree species differing in drought tolerance ability and leaf phenology. Results of this study showed that seasonal patterns of leaf phenology varied significantly with seasonal changes in stem water relations among the nine species. Leaf shedding coincided with the attainment of seasonal minimum stem water potential. Leaf flush occurred following xylem rehydration at the peak of the dry season suggesting that endogenous plant factors play a pivotal role in seasonal leaf display in this forest type. Drought-tolerant deciduous species suffered significantly higher seasonal losses in xylem hydraulic conductivity than the drought-intolerant semi-evergreen tree species (P < 0.05). There was a significant and positive correlation between species drought tolerance index and species' seasonal loss in hydraulic conductivity (P < 0.05), confirming the ecological role of long-distance xylem transport in this seasonally dry tropical forest. Our results reveal that water stress in seasonally dry tropical forests selects for water conservative traits that protect the vulnerable xylem transport system. Therefore, seasonal rhythms in xylem transport dictate patterns of leaf display in seasonally dry tropical forests.
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Affiliation(s)
- Royd Vinya
- Environmental Change Institute, School of Geography and the Environment, Oxford University Centre for the Environment, South Parks Road, Oxford, UK
- School of Natural Resources, Copperbelt University, Kitwe, Zambia
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, Oxford University Centre for the Environment, South Parks Road, Oxford, UK
| | - Nick D Brown
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, UK
| | - Joshua B Fisher
- School of Plant Sciences, University of Tasmania, Hobart, Australia
| | - Timothy Brodribb
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, USA
| | - Luiz E O C Aragão
- School of Geography, University of Exeter, Amory Building, Rennes Drive, Devon, UK
- National Institute for Space Research, INPE, Avenida dos Astronautas, 1.758, Jd. Granja, CEP 12227-010São José dos Campos, SP, Brazil
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25
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Scoffoni C, Albuquerque C, Cochard H, Buckley TN, Fletcher LR, Caringella MA, Bartlett M, Brodersen CR, Jansen S, McElrone AJ, Sack L. The Causes of Leaf Hydraulic Vulnerability and Its Influence on Gas Exchange in Arabidopsis thaliana. PLANT PHYSIOLOGY 2018; 178:1584-1601. [PMID: 30366978 PMCID: PMC6288733 DOI: 10.1104/pp.18.00743] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/15/2018] [Indexed: 05/04/2023]
Abstract
The influence of the dynamics of leaf hydraulic conductance (K leaf) diurnally and during dehydration on stomatal conductance and photosynthesis remains unclear. Using the model species Arabidopsis (Arabidopsis thaliana ecotype Columbia-0), we applied a multitiered approach including physiological measurements, high-resolution x-ray microcomputed tomography, and modeling at a range of scales to characterize (1) K leaf decline during dehydration; (2) its basis in the hydraulic conductances of leaf xylem and outside-xylem pathways (K ox); (3) the dependence of its dynamics on irradiance; (4) its impact on diurnal patterns of stomatal conductance and photosynthetic rate; and (5) its influence on gas exchange and survival under simulated drought regimes. Arabidopsis leaves showed strong vulnerability to dehydration diurnally in both gas exchange and hydraulic conductance, despite lack of xylem embolism or conduit collapse above the turgor loss point, indicating a pronounced sensitivity of K ox to dehydration. K leaf increased under higher irradiance in well-hydrated leaves across the full range of water potential, but no shift in K leaf vulnerability was observed. Modeling indicated that responses to dehydration and irradiance are likely attributable to changes in membrane permeability and that a dynamic K ox would contribute strongly to stomatal closure, improving performance, survival, and efficient water use during drought. These findings for Columbia-0 provide a baseline for assessing variation across genotypes in hydraulic traits and their influence on gas exchange during dehydration.
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Affiliation(s)
- Christine Scoffoni
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095
- Department of Biological Sciences, California State University, Los Angeles, California 90032
| | - Caetano Albuquerque
- Department of Viticulture and Enology, University of California, Davis, California 95616
| | - Hervé Cochard
- Université Clermont-Auvergne, Institut National de la Recherche Agronomique, PIAF, F-63000 Clermont-Ferrand, France
| | - Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Leila R Fletcher
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095
| | - Marissa A Caringella
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095
| | - Megan Bartlett
- Princeton Environmental Institute, Princeton University, Princeton, New Jersey 08544
| | - Craig R Brodersen
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany 89081
| | - Andrew J McElrone
- Department of Viticulture and Enology, University of California, Davis, California 95616
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095
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26
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Alston ME, Barber R. Temperature - dependent polymer absorber as a switchable state NIR reactor. Sci Rep 2018; 8:15866. [PMID: 30367076 PMCID: PMC6203727 DOI: 10.1038/s41598-018-33485-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 10/01/2018] [Indexed: 11/15/2022] Open
Abstract
This research studies a lower down transition temperature composite polymer, modulated by multi microchannel fluidic flows to advance a thermally controllable material. Through modulating volumetric flow rates to manipulate fluid-material interface for heat transport within a microfluidic platform. Determining this optimization at any given flow rate will advance fluidics acting as a filter for invisible irradiation, near IR (NIR) range of the electromagnetic spectrum. In principle, filtering out this part of the solar irradiation spectrum can be achieved by selective fluidic absorption. By switchable control of conductance states to make the material switch on for high conductance or switch off for low conductance as a heat seeking targeting material. The challenges in material science is our ability to evaluate heat flow and monitor temperature with time. This research will determine the use of microfluidics based flows to direct the structural assembly of a polymer into a thermal switch. The research is inspired by nature's vasculature leaf formations to modulate irradiance absorption by laminar fluidic flow. This bio-inspired engineering approach advances the structural assembly of polymers. By finely tuning flows to manipulate thermal gains in microchannel network architecture through flow rate switching to define composite function in differing conductance states. The research determines control of the thermodynamic state of a composite is directed by planar extensional flow in a microfluidic platform for high cooling surfaces.
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Affiliation(s)
- Mark E Alston
- University of Nottingham, Faculty of Engineering, Nottingham, NG7 2RD, United Kingdom.
| | - Robert Barber
- Scientific Research Facilities Council, Computation, Warrington, WA4 4AD, United Kingdom
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27
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Garavillon-Tournayre M, Gousset-Dupont A, Gautier F, Benoit P, Conchon P, Souchal R, Lopez D, Petel G, Venisse JS, Bastien C, Label P, Fumanal B. Integrated drought responses of black poplar: how important is phenotypic plasticity? PHYSIOLOGIA PLANTARUM 2018; 163:30-44. [PMID: 28940533 DOI: 10.1111/ppl.12646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/24/2017] [Accepted: 09/15/2017] [Indexed: 06/07/2023]
Abstract
Climate change is expected to increase drought frequency and intensity which will threaten plant growth and survival. In such fluctuating environments, perennial plants respond with hydraulic and biomass adjustments, resulting in either tolerant or avoidant strategies. Plants' response to stress relies on their phenotypic plasticity. The goal of this study was to explore physiology of young Populus nigra in the context of a time-limited and progressive water deficit in regard to their growth and stress response strategies. Fourteen French 1-year-old black poplar genotypes, geographically contrasted, were subjected to withholding water during 8 days until severe water stress. Water fluxes (i.e. leaf water potentials and stomatal conductance) were analyzed together with growth (i.e. radial and longitudinal branch growth, leaf senescence and leaf production). Phenotypic plasticity was calculated for each trait and response strategies to drought were deciphered for each genotype. Black poplar genotypes permanently were dealing with a continuum of adjusted water fluxes and growth between two extreme strategies, tolerance and avoidance. Branch growth, leaf number and leaf hydraulic potential traits had contrasted plasticities, allowing genotype characterization. The most tolerant genotype to water deficit, which maintained growth, had the lowest global phenotypic plasticity. Conversely, the most sensitive and avoidant genotype ceased growth until the season's end, had the highest plasticity level. All the remaining black poplar genotypes were close to avoidance with average levels of traits plasticity. These results underpinned the role of plasticity in black poplar response to drought and calls for its wider use into research on plants' responses to stress.
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Affiliation(s)
| | | | | | - Pierrick Benoit
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | - Pierre Conchon
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | - Romain Souchal
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | - David Lopez
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | - Gilles Petel
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | | | | | - Philippe Label
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
| | - Boris Fumanal
- Université Clermont Auvergne, INRA, PIAF, F-63000 Clermont-Ferrand, France
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28
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Zhu J, Dai Z, Vivin P, Gambetta GA, Henke M, Peccoux A, Ollat N, Delrot S. A 3-D functional-structural grapevine model that couples the dynamics of water transport with leaf gas exchange. ANNALS OF BOTANY 2018; 121:833-848. [PMID: 29293870 PMCID: PMC5906973 DOI: 10.1093/aob/mcx141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 11/01/2017] [Indexed: 05/03/2023]
Abstract
Background and Aims Predicting both plant water status and leaf gas exchange under various environmental conditions is essential for anticipating the effects of climate change on plant growth and productivity. This study developed a functional-structural grapevine model which combines a mechanistic understanding of stomatal function and photosynthesis at the leaf level (i.e. extended Farqhuhar-von Caemmerer-Berry model) and the dynamics of water transport from soil to individual leaves (i.e. Tardieu-Davies model). Methods The model included novel features that account for the effects of xylem embolism (fPLC) on leaf hydraulic conductance and residual stomatal conductance (g0), variable root and leaf hydraulic conductance, and the microclimate of individual organs. The model was calibrated with detailed datasets of leaf photosynthesis, leaf water potential, xylem sap abscisic acid (ABA) concentration and hourly whole-plant transpiration observed within a soil drying period, and validated with independent datasets of whole-plant transpiration under both well-watered and water-stressed conditions. Key Results The model well captured the effects of radiation, temperature, CO2 and vapour pressure deficit on leaf photosynthesis, transpiration, stomatal conductance and leaf water potential, and correctly reproduced the diurnal pattern and decline of water flux within the soil drying period. In silico analyses revealed that decreases in g0 with increasing fPLC were essential to avoid unrealistic drops in leaf water potential under severe water stress. Additionally, by varying the hydraulic conductance along the pathway (e.g. root and leaves) and changing the sensitivity of stomatal conductance to ABA and leaf water potential, the model can produce different water use behaviours (i.e. iso- and anisohydric). Conclusions The robust performance of this model allows for modelling climate effects from individual plants to fields, and for modelling plants with complex, non-homogenous canopies. In addition, the model provides a basis for future modelling efforts aimed at describing the physiology and growth of individual organs in relation to water status.
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Affiliation(s)
- Junqi Zhu
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, Villenave d’Ornon, France
| | - Zhanwu Dai
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, Villenave d’Ornon, France
| | - Philippe Vivin
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, Villenave d’Ornon, France
| | - Gregory A Gambetta
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, Villenave d’Ornon, France
| | - Michael Henke
- Department of Ecoinformatics, Biometrics and Forest Growth, University of Göttingen, Göttingen, Germany
| | - Anthony Peccoux
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, Villenave d’Ornon, France
| | - Nathalie Ollat
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, Villenave d’Ornon, France
| | - Serge Delrot
- EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, Villenave d’Ornon, France
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29
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Johnson DM, Berry ZC, Baker KV, Smith DD, McCulloh KA, Domec J. Leaf hydraulic parameters are more plastic in species that experience a wider range of leaf water potentials. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13049] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Z. Carter Berry
- Department of Natural Resources and the Environment University of New Hampshire Durham NH USA
| | | | - Duncan D. Smith
- Department of Botany University of Wisconsin‐Madison Madison WI USA
| | | | - Jean‐Christophe Domec
- Bordeaux Sciences Agro UMR INRA‐ISPA 1391 Gradignan France
- Nicholas School of the Environment Duke University Durham NC USA
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30
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Ohtsuka A, Sack L, Taneda H. Bundle sheath lignification mediates the linkage of leaf hydraulics and venation. PLANT, CELL & ENVIRONMENT 2018; 41:342-353. [PMID: 29044569 DOI: 10.1111/pce.13087] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 09/23/2017] [Accepted: 09/28/2017] [Indexed: 06/07/2023]
Abstract
The lignification of the leaf vein bundle sheath (BS) has been observed in many species and would reduce conductance from xylem to mesophyll. We hypothesized that lignification of the BS in lower-order veins would provide benefits for water delivery through the vein hierarchy but that the lignification of higher-order veins would limit transport capacity from xylem to mesophyll and leaf hydraulic conductance (Kleaf ). We further hypothesized that BS lignification would mediate the relationship of Kleaf to vein length per area. We analysed the dependence of Kleaf , and its light response, on the lignification of the BS across vein orders for 11 angiosperm tree species. Eight of 11 species had lignin deposits in the BS of the midrib, and two species additionally only in their secondary veins, and for six species up to their minor veins. Species with lignification of minor veins had a lower hydraulic conductance of xylem and outside-xylem pathways and lower Kleaf . Kleaf could be strongly predicted by vein length per area and highest lignified vein order (R2 = .69). The light-response of Kleaf was statistically independent of BS lignification. The lignification of the BS is an important determinant of species variation in leaf and thus whole plant water transport.
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Affiliation(s)
- Akihiro Ohtsuka
- Asahi Kasei Corporation, Tokyo, 100-8550, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Haruhiko Taneda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
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31
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Tomasella M, Beikircher B, Häberle KH, Hesse B, Kallenbach C, Matyssek R, Mayr S. Acclimation of branch and leaf hydraulics in adult Fagus sylvatica and Picea abies in a forest through-fall exclusion experiment. TREE PHYSIOLOGY 2018; 38:198-211. [PMID: 29177459 DOI: 10.1093/treephys/tpx140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/03/2017] [Indexed: 05/26/2023]
Abstract
Decreasing water availability due to climate change poses the question of whether and to what extent tree species are able to hydraulically acclimate and how hydraulic traits of stems and leaves are coordinated under drought. In a through-fall exclusion experiment, hydraulic acclimation was analyzed in a mixed forest stand of Fagus sylvatica L. and Picea abies (L.) Karst. In drought-stressed (TE, through-fall exclusion over 2 years) and control (CO) trees, hydraulic vulnerability was studied in branches as well as in leaves (F. sylvatica) and end-twigs (P. abies, entirely formed during the drought period) sampled at the same height in sun-exposed portions of the tree crown. In addition, relevant xylem anatomical traits and leaf pressure-volume relations were analyzed. The TE trees reached pre-dawn water potentials down to -1.6 MPa. In both species, water potentials at 50% loss of xylem hydraulic conductivity were ~0.4 MPa more negative in TE than in CO branches. Foliage hydraulic vulnerability (expressed as water potential at 50% loss of leaf/end-twig hydraulic conductance) and water potential at turgor loss point were also, respectively, 0.4 and 0.5 MPa lower in TE trees. Minor differences were observed in conduit mean hydraulic diameter and cell wall reinforcement. Our findings indicate significant and fast hydraulic acclimation under relatively mild drought in both tree species. Acclimation was well coordinated between branches and foliage, which might be essential for survival and productivity of mature trees under future drought periods.
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Affiliation(s)
- Martina Tomasella
- Department of Ecology and Ecosystem Management, Chair for Ecophysiology of Plants, Technical University of Munich, Hans-Carl-von-Carlowitz Platz 2, 85354 Freising, Germany
| | - Barbara Beikircher
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Karl-Heinz Häberle
- Department of Ecology and Ecosystem Management, Chair for Ecophysiology of Plants, Technical University of Munich, Hans-Carl-von-Carlowitz Platz 2, 85354 Freising, Germany
| | - Benjamin Hesse
- Department of Ecology and Ecosystem Management, Chair for Ecophysiology of Plants, Technical University of Munich, Hans-Carl-von-Carlowitz Platz 2, 85354 Freising, Germany
| | - Christian Kallenbach
- Department of Ecology and Ecosystem Management, Chair for Ecophysiology of Plants, Technical University of Munich, Hans-Carl-von-Carlowitz Platz 2, 85354 Freising, Germany
| | - Rainer Matyssek
- Department of Ecology and Ecosystem Management, Chair for Ecophysiology of Plants, Technical University of Munich, Hans-Carl-von-Carlowitz Platz 2, 85354 Freising, Germany
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
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Shelden MC, Vandeleur R, Kaiser BN, Tyerman SD. A Comparison of Petiole Hydraulics and Aquaporin Expression in an Anisohydric and Isohydric Cultivar of Grapevine in Response to Water-Stress Induced Cavitation. FRONTIERS IN PLANT SCIENCE 2017; 8:1893. [PMID: 29163613 PMCID: PMC5681967 DOI: 10.3389/fpls.2017.01893] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 10/19/2017] [Indexed: 05/11/2023]
Abstract
We report physiological, anatomical and molecular differences in two economically important grapevine (Vitis vinifera L.) cultivars cv. Grenache (near-isohydric) and Chardonnay (anisohydric) in their response to water-stress induced cavitation. The aim of the study was to compare organ vulnerability (petiole and stem) to cavitation by measuring ultrasonic acoustic emissions (UAE) and percent loss of conductance of potted grapevines subject to the onset of water-stress. Leaf (ψL) and stem water potential (ψS), stomatal conductance (gs), transpiration (E), petiole hydraulics (KPet), and xylem diameter were also measured. Chardonnay displayed hydraulic segmentation based on UAE, with cavitation occurring at a less negative ψL in the petiole than in the stem. Vulnerability segmentation was not observed in Grenache, with both petioles and stems equally vulnerable to cavitation. Leaf water potential that induced 50% of maximum UAE was significantly different between petioles and stems in Chardonnay (ψ50Petiole = -1.14 and ψ50Stem = -2.24 MPa) but not in Grenache (ψ50Petiole = -0.73 and ψ50Stem = -0.78 MPa). Grenache stems appeared more susceptible to water-stress induced cavitation than Chardonnay stems. Grenache displayed (on average) a higher KPet likely due to the presence of larger xylem vessels. A close relationship between petiole hydraulic properties and vine water status was observed in Chardonnay but not in Grenache. Transcriptional analysis of aquaporins in the petioles and leaves (VvPIP1;1, VvPIP2;1, VvPIP2;2 VvPIP2;3, VvTIP1;1, and VvTIP2;1) showed differential regulation diurnally and in response to water-stress. VvPIP2;1 showed strong diurnal regulation in the petioles and leaves of both cultivars with expression highest predawn. Expression of VvPIP2;1 and VvPIP2;2 responded to ψL and ψS in both cultivars indicating the expression of these two genes are closely linked to vine water status. Expression of several aquaporin genes correlated with gas exchange measurements, however, these genes differed between cultivars. In summary, the data shows two contrasting responses in petiole hydraulics and aquaporin expression between the near-isohydric cultivar, Grenache and anisohydric cultivar, Chardonnay.
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Affiliation(s)
- Megan C. Shelden
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Adelaide, SA, Australia
| | - Rebecca Vandeleur
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Adelaide, SA, Australia
| | - Brent N. Kaiser
- Centre for Carbon, Water and Food, School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, NSW, Australia
| | - Stephen D. Tyerman
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Adelaide, SA, Australia
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Savi T, Miotto A, Petruzzellis F, Losso A, Pacilè S, Tromba G, Mayr S, Nardini A. Drought-induced embolism in stems of sunflower: A comparison of in vivo micro-CT observations and destructive hydraulic measurements. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 120:24-29. [PMID: 28968592 DOI: 10.1016/j.plaphy.2017.09.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 05/23/2023]
Abstract
Vulnerability curves (VCs) are a useful tool to investigate the susceptibility of plants to drought-induced hydraulic failure, and several experimental techniques have been used for their measurement. The validity of the bench dehydration method coupled to hydraulic measurements, considered as a 'golden standard', has been recently questioned calling for its validation with non-destructive methods. We compared the VCs of a herbaceous crop plant (Helianthus annuus) obtained during whole-plant dehydration followed by i) hydraulic flow measurements in stem segments (classical destructive method) or by ii) in vivo micro-CT observations of stem xylem conduits in intact plants. The interpolated P50 values (xylem water potential inducing 50% loss of hydraulic conductance) were -1.74 MPa and -0.87 MPa for the hydraulic and the micro-CT VC, respectively. Interpolated P20 values were similar, while P50 and P80 were significantly different, as evidenced by non-overlapping 95% confidence intervals. Our results did not support the tension-cutting artefact, as no overestimation of vulnerability was observed when comparing the hydraulic VC to that obtained with in vivo imaging. After one scan, 25% of plants showed signs of x-ray induced damage, while three successive scans caused the formation of a circular brownish scar in all tested plants. Our results support the validity of hydraulic measurements of samples excised under tension provided standard sampling and handling protocols are followed, but also show that caution is needed when investigating vital plant processes with x-ray imaging.
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Affiliation(s)
- Tadeja Savi
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy.
| | - Andrea Miotto
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Adriano Losso
- Institut für Botanik, Universität Innsbruck, Sternwarterstrasse 15, A-6020 Innsbruck, Austria
| | - Serena Pacilè
- Elettra-Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy; Dipartimento di Ingegneria e Architettura, Università di Trieste, Piazzale Europa 1, 34127 Trieste, Italy
| | - Giuliana Tromba
- Elettra-Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Stefan Mayr
- Institut für Botanik, Universität Innsbruck, Sternwarterstrasse 15, A-6020 Innsbruck, Austria
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
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Dayer S, Peña JP, Gindro K, Torregrosa L, Voinesco F, Martínez L, Prieto JA, Zufferey V. Changes in leaf stomatal conductance, petiole hydraulics and vessel morphology in grapevine (Vitis vinifera cv. Chasselas) under different light and irrigation regimes. FUNCTIONAL PLANT BIOLOGY : FPB 2017; 44:679-693. [PMID: 32480598 DOI: 10.1071/fp16041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/21/2017] [Indexed: 06/11/2023]
Abstract
Hydraulic conductance and water transport in plants may be affected by environmental factors, which in turn regulate leaf gas exchange, plant growth and yield. In this study, we assessed the combined effects of radiation and water regimes on leaf stomatal conductance (gs), petiole specific hydraulic conductivity (Kpetiole) and anatomy (vessel number and size); and leaf aquaporin gene expression of field-grown grapevines at the Agroscope Research Station (Leytron, Switzerland). Chasselas vines were subjected to two radiation (sun and shade) levels combined with two water (irrigated and water-stressed) regimes. The sun and shade leaves received ~61.2 and 1.48molm-2day-1 of photosynthetically active radiation, respectively, during a clear-sky day. The irrigated vines were watered weekly from bloom to veraison whereas the water-stressed vines did not receive any irrigation during the season. Water stress reduced gs and Kpetiole relative to irrigated vines throughout the season. The petioles from water-stressed vines showed fewer large-sized vessels than those from irrigated vines. The shaded leaves from the irrigated vines exhibited a higher Kpetiole than the sun leaves at the end of the season, which was partially explained by a higher number of vessels per petiole and possibly by the upregulation of some of the aquaporins measured in the leaf. These results suggest that not only plant water status but also the light environment at the leaf level affected leaf and petiole hydraulics.
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Affiliation(s)
- Silvina Dayer
- INTA EEA Mendoza, San Martín 3853, Luján de Cuyo (5507), Mendoza, Argentina
| | - Jorge Perez Peña
- INTA EEA Mendoza, San Martín 3853, Luján de Cuyo (5507), Mendoza, Argentina
| | - Katia Gindro
- Agroscope, Institut des sciences en production végétale IPV, Route de Duillier 50, 1260 Nyon, Switzerland
| | - Laurent Torregrosa
- Montpellier SupAgro, UMR AGAP - DAAV research group, 2 place Viala, 34060 Montpellier Cedex 01, France
| | - Francine Voinesco
- Agroscope, Institut des sciences en production végétale IPV, Route de Duillier 50, 1260 Nyon, Switzerland
| | - Liliana Martínez
- Cátedra de Fisiología Vegetal, Facultad de Ciencias Agrarias, UNCuyo, Almirante Brown 500, 5507 Chacras de Coria, Argentina
| | - Jorge A Prieto
- INTA EEA Mendoza, San Martín 3853, Luján de Cuyo (5507), Mendoza, Argentina
| | - Vivian Zufferey
- Agroscope, Institut des sciences en production végétale IPV, Route de Duillier 50, 1260 Nyon, Switzerland
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Scoffoni C, Albuquerque C, Brodersen CR, Townes SV, John GP, Bartlett MK, Buckley TN, McElrone AJ, Sack L. Outside-Xylem Vulnerability, Not Xylem Embolism, Controls Leaf Hydraulic Decline during Dehydration. PLANT PHYSIOLOGY 2017; 173:1197-1210. [PMID: 28049739 PMCID: PMC5291720 DOI: 10.1104/pp.16.01643] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/28/2016] [Indexed: 05/18/2023]
Abstract
Leaf hydraulic supply is crucial to maintaining open stomata for CO2 capture and plant growth. During drought-induced dehydration, the leaf hydraulic conductance (Kleaf) declines, which contributes to stomatal closure and, eventually, to leaf death. Previous studies have tended to attribute the decline of Kleaf to embolism in the leaf vein xylem. We visualized at high resolution and quantified experimentally the hydraulic vulnerability of xylem and outside-xylem pathways and modeled their respective influences on plant water transport. Evidence from all approaches indicated that the decline of Kleaf during dehydration arose first and foremost due to the vulnerability of outside-xylem tissues. In vivo x-ray microcomputed tomography of dehydrating leaves of four diverse angiosperm species showed that, at the turgor loss point, only small fractions of leaf vein xylem conduits were embolized, and substantial xylem embolism arose only under severe dehydration. Experiments on an expanded set of eight angiosperm species showed that outside-xylem hydraulic vulnerability explained 75% to 100% of Kleaf decline across the range of dehydration from mild water stress to beyond turgor loss point. Spatially explicit modeling of leaf water transport pointed to a role for reduced membrane conductivity consistent with published data for cells and tissues. Plant-scale modeling suggested that outside-xylem hydraulic vulnerability can protect the xylem from tensions that would induce embolism and disruption of water transport under mild to moderate soil and atmospheric droughts. These findings pinpoint outside-xylem tissues as a central locus for the control of leaf and plant water transport during progressive drought.
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Affiliation(s)
- Christine Scoffoni
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.);
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.);
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.);
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.);
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
| | - Caetano Albuquerque
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.)
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.)
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.)
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
| | - Craig R Brodersen
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.)
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.)
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.)
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
| | - Shatara V Townes
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.)
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.)
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.)
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
| | - Grace P John
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.)
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.)
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.)
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
| | - Megan K Bartlett
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.)
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.)
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.)
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
| | - Thomas N Buckley
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.)
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.)
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.)
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
| | - Andrew J McElrone
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.)
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.)
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.)
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095 (C.S., S.V.T., G.P.J., M.K.B., L.S.)
- Department of Biology, Utah State University, Logan, Utah 84322 (C.S.)
- Department of Viticulture and Enology, University of California, Davis, California 95616 (C.A., A.J.M.)
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511 (C.R.B.)
- IA Watson Grains Research Centre, Plant Breeding Institute, Sydney Institute of Agriculture, University of Sydney, Narrabri, New South Wales 2390, Australia (T.N.B.); and
- United States Department of Agriculture-Agricultural Research Service, Davis, California 95616 (A.J.M.)
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36
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Nardini A, Savi T, Trifilò P, Lo Gullo MA. Drought Stress and the Recovery from Xylem Embolism in Woody Plants. PROGRESS IN BOTANY VOL. 79 2017. [DOI: 10.1007/124_2017_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Tabassum MA, Zhu G, Hafeez A, Wahid MA, Shaban M, Li Y. Influence of leaf vein density and thickness on hydraulic conductance and photosynthesis in rice (Oryza sativa L.) during water stress. Sci Rep 2016; 6:36894. [PMID: 27848980 PMCID: PMC5111110 DOI: 10.1038/srep36894] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 10/18/2016] [Indexed: 11/09/2022] Open
Abstract
The leaf venation architecture is an ideal, highly structured and efficient irrigation system in plant leaves. Leaf vein density (LVD) and vein thickness are the two major properties of this system. Leaf laminae carry out photosynthesis to harvest the maximum biological yield. It is still unknown whether the LVD and/or leaf vein thickness determines the plant hydraulic conductance (Kplant) and leaf photosynthetic rate (A). To investigate this topic, the current study was conducted with two varieties under three PEG-induced water deficit stress (PEG-IWDS) levels. The results showed that PEG-IWDS significantly decreased A, stomatal conductance (gs), and Kplant in both cultivars, though the IR-64 strain showed more severe decreases than the Hanyou-3 strain. PEG-IWDS significantly decreased the major vein thickness, while it had no significant effect on LVD. A, gs and Kplant were positively correlated with each other, and they were negatively correlated with LVD. A, gs and Kplant were positively correlated with the inter-vein distance and major vein thickness. Therefore, the decreased photosynthesis and hydraulic conductance in rice plants under water deficit conditions are related to the decrease in the major vein thickness.
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Affiliation(s)
- Muhammad Adnan Tabassum
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Guanglong Zhu
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Abdul Hafeez
- Cotton Physiology Lab for Efficient Production, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Muhammad Atif Wahid
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Muhammad Shaban
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yong Li
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
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38
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Trifiló P, Raimondo F, Savi T, Lo Gullo MA, Nardini A. The contribution of vascular and extra-vascular water pathways to drought-induced decline of leaf hydraulic conductance. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:5029-5039. [PMID: 27388214 DOI: 10.1093/jxb/erw268] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Drought stress can impair leaf hydraulic conductance (Kleaf), but the relative contribution of changes in the efficiency of the vein xylem water pathway and in the mesophyll route outside the xylem in driving the decline of Kleaf is still debated. We report direct measurements of dehydration-induced changes in the hydraulic resistance (R=1/K) of whole leaf (Rleaf), as well as of the leaf xylem (Rx) and extra-vascular pathways (Rox) in four Angiosperm species. Rleaf, Rx, and Rox were measured using the vacuum chamber method (VCM). Rleaf values during progressive leaf dehydration were also validated with measurements performed using the rehydration kinetic method (RKM). We analysed correlations between changes in Rx or Rox and Rleaf, as well as between morpho-anatomical traits (including dehydration-induced leaf shrinkage), vulnerability to embolism, and leaf water relation parameters. Measurements revealed that the relative contribution of vascular and extra-vascular hydraulic properties in driving Kleaf decline during dehydration is species-specific. Whilst in two study species the progressive impairment of both vascular and extra-vascular pathways contributed to leaf hydraulic vulnerability, in the other two species the vascular pathway remained substantially unaltered during leaf dehydration, and Kleaf decline was apparently caused only by changes in the hydraulic properties of the extra-vascular compartment.
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Affiliation(s)
- Patrizia Trifiló
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Università di Messina, Salita F. Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Fabio Raimondo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Università di Messina, Salita F. Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Tadeja Savi
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Maria A Lo Gullo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Università di Messina, Salita F. Stagno D'Alcontres 31, 98166 Messina, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
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West AG, Nel JA, Bond WJ, Midgley JJ. Experimental evidence for heat plume-induced cavitation and xylem deformation as a mechanism of rapid post-fire tree mortality. THE NEW PHYTOLOGIST 2016; 211:828-38. [PMID: 27152877 PMCID: PMC5084795 DOI: 10.1111/nph.13979] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 03/18/2016] [Indexed: 05/17/2023]
Abstract
Recent work suggests that hydraulic mechanisms, rather than cambium necrosis, may account for rapid post-fire tree mortality. We experimentally tested for xylem cavitation, as a result of exposure to high-vapour-deficit (D) heat plumes, and permanent xylem deformation, as a result of thermal softening of lignin, in two tree species differing in fire tolerance. We measured percentage loss of conductance (PLC) in distal branches that had been exposed to high-D heat plumes or immersed in hot water baths (high temperature, but not D). Results were compared with predictions from a parameterized hydraulic model. Physical damage to the xylem was examined microscopically. Both species suffered c. 80% PLC when exposed to a 100°C plume. However, at 70°C, the fire-sensitive Kiggelaria africana suffered lower PLC (49%) than the fire-resistant Eucalytpus cladocalyx (80%). Model simulations suggested that differences in PLC between species were a result of greater hydraulic segmentation in E. cladocalyx. Kiggelaria africana suffered considerable PLC (59%), as a result of heat-induced xylem deformation, in the water bath treatments, but E. cladocalyx did not. We suggest that a suite of 'pyrohydraulic' traits, including hydraulic segmentation and heat sensitivity of the xylem, may help to explain why some tree species experience rapid post-fire mortality after low-intensity fires and others do not.
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Affiliation(s)
- Adam G. West
- Department of Biological SciencesUniversity of Cape TownRondebosch7700South Africa
| | - Jacques A. Nel
- Department of Biological SciencesUniversity of Cape TownRondebosch7700South Africa
| | - William J. Bond
- Department of Biological SciencesUniversity of Cape TownRondebosch7700South Africa
| | - Jeremy J. Midgley
- Department of Biological SciencesUniversity of Cape TownRondebosch7700South Africa
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40
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Hernandez-Santana V, Rodriguez-Dominguez CM, Fernández JE, Diaz-Espejo A. Role of leaf hydraulic conductance in the regulation of stomatal conductance in almond and olive in response to water stress. TREE PHYSIOLOGY 2016; 36:725-35. [PMID: 26846979 DOI: 10.1093/treephys/tpv146] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 12/22/2015] [Indexed: 05/06/2023]
Abstract
The decrease of stomatal conductance (gs) is one of the prime responses to water shortage and the main determinant of yield limitation in fruit trees. Understanding the mechanisms related to stomatal closure in response to imposed water stress is crucial for correct irrigation management. The loss of leaf hydraulic functioning is considered as one of the major factors triggering stomatal closure. Thus, we conducted an experiment to quantify the dehydration response of leaf hydraulic conductance (Kleaf) and its impact on gs in two Mediterranean fruit tree species, one deciduous (almond) and one evergreen (olive). Our hypothesis was that a higher Kleaf would be associated with a higher gs and that the reduction in Kleaf would predict the reduction in gs in both species. We measured Kleaf in olive and almond during a cycle of irrigation withholding. We also compared the results of two methods to measure Kleaf: dynamic rehydration kinetics and evaporative flux methods. In addition, determined gs, leaf water potential (Ψleaf), vein density, photosynthetic capacity and turgor loss point. Results showed that gs was higher in almond than in olive and so was Kleaf (Kmax = 4.70 and 3.42 mmol s(-1) MPa(-1) m(-2), in almond and olive, respectively) for Ψleaf > -1.2 MPa. At greater water stress levels than -1.2 MPa, however, Kleaf decreased exponentially, being similar for both species, while gs was still higher in almond than in olive. We conclude that although the Kleaf decrease with increasing water stress does not drive unequivocally the gs response to water stress, Kleaf is the variable most strongly related to the gs response to water stress, especially in olive. Other variables such as the increase in abscisic acid (ABA) may be playing an important role in gs regulation, although in our study the gs-ABA relationship did not show a clear pattern.
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Affiliation(s)
- Virginia Hernandez-Santana
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, no. 10, 41012 Sevilla, Spain
| | - Celia M Rodriguez-Dominguez
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, no. 10, 41012 Sevilla, Spain
| | - J Enrique Fernández
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, no. 10, 41012 Sevilla, Spain
| | - Antonio Diaz-Espejo
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, no. 10, 41012 Sevilla, Spain
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41
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Peschiutta ML, Bucci SJ, Scholz FG, Goldstein G. Compensatory responses in plant-herbivore interactions: Impacts of insects on leaf water relations. ACTA OECOLOGICA 2016. [DOI: 10.1016/j.actao.2016.03.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Ryu J, Hwang BG, Kim YX, Lee SJ. Direct observation of local xylem embolisms induced by soil drying in intact Zea mays leaves. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:2617-26. [PMID: 26946123 PMCID: PMC4861012 DOI: 10.1093/jxb/erw087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The vulnerability of vascular plants to xylem embolism is closely related to their stable long-distance water transport, growth, and survival. Direct measurements of xylem embolism are required to understand what causes embolism and what strategies plants employ against it. In this study, synchrotron X-ray microscopy was used to non-destructively investigate both the anatomical structures of xylem vessels and embolism occurrence in the leaves of intact Zea mays (maize) plants. Xylem embolism was induced by water stress at various soil drying periods and soil water contents. X-ray images of dehydrated maize leaves showed that the ratio of gas-filled vessels to all xylem vessels increased with decreased soil water content and reached approximately 30% under severe water stress. Embolism occurred in some but not all vessels. Embolism in maize leaves was not strongly correlated with xylem diameter but was more likely to occur in the peripheral veins. The rate of embolism formation in metaxylem vessels was higher than in protoxylem vessels. This work has demonstrated that xylem embolism remains low in maize leaves under water stress and that there xylem has characteristic spatial traits of vulnerability to embolism.
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Affiliation(s)
- Jeongeun Ryu
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784, Republic of Korea Center for Biofluid and Biomimic Research, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784, Republic of Korea
| | - Bae Geun Hwang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784, Republic of Korea Center for Biofluid and Biomimic Research, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784, Republic of Korea
| | - Yangmin X Kim
- Center for Biofluid and Biomimic Research, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784, Republic of Korea
| | - Sang Joon Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784, Republic of Korea Center for Biofluid and Biomimic Research, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784, Republic of Korea
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Schuldt B, Knutzen F, Delzon S, Jansen S, Müller-Haubold H, Burlett R, Clough Y, Leuschner C. How adaptable is the hydraulic system of European beech in the face of climate change-related precipitation reduction? THE NEW PHYTOLOGIST 2016; 210:443-58. [PMID: 26720626 DOI: 10.1111/nph.13798] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/06/2015] [Indexed: 05/04/2023]
Abstract
Climate warming will increase the drought exposure of many forests world-wide. It is not well understood how trees adapt their hydraulic architecture to a long-term decrease in water availability. We examined 23 traits characterizing the hydraulic architecture and growth rate of branches and the dependent foliage of mature European beech (Fagus sylvatica) trees along a precipitation gradient (855-594 mm yr(-1) ) on uniform soil. A main goal was to identify traits that are associated with xylem efficiency, safety and growth. Our data demonstrate for the first time a linear increase in embolism resistance with climatic aridity (by 10%) across populations within a species. Simultaneously, vessel diameter declined by 7% and pit membrane thickness (Tm ) increased by 15%. Although specific conductivity did not change, leaf-specific conductivity declined by 40% with decreasing precipitation. Of eight plant traits commonly associated with embolism resistance, only vessel density in combination with pathway redundancy and Tm were related. We did not confirm the widely assumed trade-off between xylem safety and efficiency but obtained evidence in support of a positive relationship between hydraulic efficiency and growth. We conclude that the branch hydraulic system of beech has a distinct adaptive potential to respond to a precipitation reduction as a result of the environmental control of embolism resistance.
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Affiliation(s)
- Bernhard Schuldt
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany
| | - Florian Knutzen
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany
| | - Sylvain Delzon
- UMR BIOGECO INRA-UB, University of Bordeaux, Avenue des Facultés, 33405, Talence, France
| | - Steven Jansen
- Institute for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Hilmar Müller-Haubold
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany
| | - Régis Burlett
- UMR BIOGECO INRA-UB, University of Bordeaux, Avenue des Facultés, 33405, Talence, France
| | - Yann Clough
- Centre for Environmental and Climate Research, Faculty of Science, Lund University, Sölvegatan 37, 223 62, Lund, Sweden
| | - Christoph Leuschner
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany
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Acoustic Emissions to Measure Drought-Induced Cavitation in Plants. APPLIED SCIENCES-BASEL 2016. [DOI: 10.3390/app6030071] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Li S, Feifel M, Karimi Z, Schuldt B, Choat B, Jansen S. Leaf gas exchange performance and the lethal water potential of five European species during drought. TREE PHYSIOLOGY 2016; 36:179-92. [PMID: 26614785 DOI: 10.1093/treephys/tpv117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 10/05/2015] [Indexed: 05/04/2023]
Abstract
Establishing physiological thresholds to drought-induced mortality in a range of plant species is crucial in understanding how plants respond to severe drought. Here, five common European tree species were selected (Acer campestre L., Acer pseudoplatanus L., Carpinus betulus L., Corylus avellana L. and Fraxinus excelsior L.) to study their hydraulic thresholds to mortality. Photosynthetic parameters during desiccation and the recovery of leaf gas exchange after rewatering were measured. Stem vulnerability curves and leaf pressure-volume curves were investigated to understand the hydraulic coordination of stem and leaf tissue traits. Stem and root samples from well-watered and severely drought-stressed plants of two species were observed using transmission electron microscopy to visualize mortality of cambial cells. The lethal water potential (ψlethal) correlated with stem P99 (i.e., the xylem water potential at 99% loss of hydraulic conductivity, PLC). However, several plants that were stressed beyond the water potential at 100% PLC showed complete recovery during the next spring, which suggests that the ψlethal values were underestimated. Moreover, we observed a 1 : 1 relationship between the xylem water potential at the onset of embolism and stomatal closure, confirming hydraulic coordination between leaf and stem tissues. Finally, ultrastructural changes in the cytoplasm of cambium tissue and mortality of cambial cells are proposed to provide an alternative approach to investigate the point of no return associated with plant death.
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Affiliation(s)
- Shan Li
- Institute for Systematic Botany and Ecology, Ulm University, D-89081 Ulm, Germany
| | - Marion Feifel
- Institute for Systematic Botany and Ecology, Ulm University, D-89081 Ulm, Germany
| | - Zohreh Karimi
- Institute for Systematic Botany and Ecology, Ulm University, D-89081 Ulm, Germany Department of Biology, Faculty of Science, Golestan University, 36154 Gorgan, Iran
| | - Bernhard Schuldt
- Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, D-37077 Göttingen, Germany
| | - Brendan Choat
- University of Western Sydney, Hawkesbury Institute for the Environment, Richmond, NSW 2753, Australia
| | - Steven Jansen
- Institute for Systematic Botany and Ecology, Ulm University, D-89081 Ulm, Germany
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Vonasek E, Nitin N. Influence of Vacuum Cooling on Escherichia coli O157:H7 Infiltration in Fresh Leafy Greens via a Multiphoton-Imaging Approach. Appl Environ Microbiol 2016; 82:106-15. [PMID: 26475109 PMCID: PMC4702619 DOI: 10.1128/aem.02327-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 10/12/2015] [Indexed: 11/20/2022] Open
Abstract
Microbial pathogen infiltration in fresh leafy greens is a significant food safety risk factor. In various postharvest operations, vacuum cooling is a critical process for maintaining the quality of fresh produce. The overall goal of this study was to evaluate the risk of vacuum cooling-induced infiltration of Escherichia coli O157:H7 into lettuce using multiphoton microscopy. Multiphoton imaging was chosen as the method to locate E. coli O157:H7 within an intact lettuce leaf due to its high spatial resolution, low background fluorescence, and near-infrared (NIR) excitation source compared to those of conventional confocal microscopy. The variables vacuum cooling, surface moisture, and leaf side were evaluated in a three-way factorial study with E. coli O157:H7 on lettuce. A total of 188 image stacks were collected. The images were analyzed for E. coli O157:H7 association with stomata and E. coli O157:H7 infiltration. The quantitative imaging data were statistically analyzed using analysis of variance (ANOVA). The results indicate that the low-moisture condition led to an increased risk of microbial association with stomata (P < 0.05). Additionally, the interaction between vacuum cooling levels and moisture levels led to an increased risk of infiltration (P < 0.05). This study also demonstrates the potential of multiphoton imaging for improving sensitivity and resolution of imaging-based measurements of microbial interactions with intact leaf structures, including infiltration.
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Affiliation(s)
- Erica Vonasek
- Department of Biological and Agricultural Engineering, University of California, Davis, Davis, California, USA
| | - Nitin Nitin
- Department of Biological and Agricultural Engineering, University of California, Davis, Davis, California, USA Department of Food Science & Technology, University of California, Davis, Davis, California, USA
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Shen F, Cheng Y, Zhang L, Gao R, Shao X. Experimental study of the types of cavitation by air seeding using light microscopy. TREE PHYSIOLOGY 2015; 35:1325-1332. [PMID: 26338303 DOI: 10.1093/treephys/tpv060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/28/2015] [Indexed: 06/05/2023]
Abstract
Recently, three types of cavitation: (i) expanding gradually; (ii) expanding-exploding, becoming a long-shaped bubble-lengthening by degrees; (iii) suddenly exploding and fully filling the conduit instantly, were proposed. Directed by this theory, experiments were performed using light microscopy to study the natural drying processes of xylem sections of Platycladus orientalis (L.) Franco. Three different phenomena of gas filling process in conduits were captured by replaying recorded videos. The first phenomenon is that a bubble emerging in a conduit expands and elongates gradually to fill the conduit. The second phenomenon is that a bubble emerging in a conduit expands gradually, and then suddenly becomes long-shaped, and extends continuously. The third phenomenon is that a bubble instantly fully fills a conduit. This paper suggests in these experiments that after losing the bulk water of a section, as the water stress of that section became more severe, the water pressures of different conduits of the section were not necessarily the same, and as time went on, the water pressures decreased constantly. Considering some practical factors, the three phenomena captured in our experiment are explained by our theory.
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Affiliation(s)
- Fanyi Shen
- College of Science, Beijing Forestry University, Beijing 100083, PR China
| | - Yanxia Cheng
- College of Science, Beijing Forestry University, Beijing 100083, PR China
| | - Li Zhang
- College of Science, Beijing Forestry University, Beijing 100083, PR China
| | - Rongfu Gao
- College of Biology, Beijing Forestry University, Beijing 100083, PR China
| | - Xuemeng Shao
- College of Science, Beijing Forestry University, Beijing 100083, PR China
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49
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Nolf M, Beikircher B, Rosner S, Nolf A, Mayr S. Xylem cavitation resistance can be estimated based on time-dependent rate of acoustic emissions. THE NEW PHYTOLOGIST 2015; 208:625-32. [PMID: 26010417 PMCID: PMC4744691 DOI: 10.1111/nph.13476] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/22/2015] [Indexed: 05/05/2023]
Abstract
Acoustic emission (AE) analysis allows nondestructive monitoring of embolism formation in plant xylem, but signal interpretation and agreement of acoustically measured hydraulic vulnerability with reference hydraulic techniques remain under debate. We compared the hydraulic vulnerability of 16 species and three crop tree cultivars using hydraulic flow measurements and acoustic emission monitoring, proposing the use of time-dependent AE rates as a novel parameter for AE analysis. There was a linear correlation between the water potential (Ψ) at 50% loss of hydraulic conductivity (P50 ) and the Ψ at maximum AE activity (Pmaxrate ), where species with lower P50 also had lower Pmaxrate (P < 0.001, R(2) = 0.76). Using AE rates instead of cumulative counts for AE analysis allows more efficient estimation of P50 , while excluding problematic AE at late stages of dehydration.
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Affiliation(s)
- Markus Nolf
- Institute of BotanyUniversity of InnsbruckSternwartestr. 15Innsbruck6020Austria
- Hawkesbury Institute for the EnvironmentUniversity of Western SydneyRichmondNSW2753Australia
| | - Barbara Beikircher
- Institute of BotanyUniversity of InnsbruckSternwartestr. 15Innsbruck6020Austria
| | - Sabine Rosner
- Institute of BotanyBOKU ViennaGregor Mendel Str. 33Vienna1180Austria
| | - Anton Nolf
- Institute for Experimental PhysicsUniversity of InnsbruckTechnikerstr. 25Innsbruck6020Austria
| | - Stefan Mayr
- Institute of BotanyUniversity of InnsbruckSternwartestr. 15Innsbruck6020Austria
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50
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Zwieniecki MA, Secchi F. Threats to xylem hydraulic function of trees under 'new climate normal' conditions. PLANT, CELL & ENVIRONMENT 2015; 38:1713-24. [PMID: 25039674 DOI: 10.1111/pce.12412] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 07/02/2014] [Accepted: 07/06/2014] [Indexed: 05/23/2023]
Abstract
Climate models predict increases in frequency and intensity of extreme environmental conditions, such as changes to minimum and maximum temperatures, duration of drought periods, intensity of rainfall/snowfall events and wind strength. These local extremes, rather than average climatic conditions, are closely linked to woody plant survival, as trees cope with such events over long lifespans. While the xylem provides trees with structural strength and is considered the most robust part of a tree's structure, it is also the most physiologically vulnerable as tree survival depends on its ability to sustain water supply to the tree crown under variable environmental conditions. Many structural, functional and biological tree properties evolved to protect xylem from loss of transport function because of embolism or to restore xylem transport capacity following embolism formation. How 'the new climate normal' conditions will affect these evolved strategies is yet to be seen. Our understanding of xylem physiology and current conceptual models describing embolism formation and plant recovery from water stress, however, can provide insight into near-future challenges that woody plants will face. In addition, knowledge of species-specific properties of xylem function may help guide mitigation of climate change impacts on woody plants in natural and agricultural tree communities.
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Affiliation(s)
- Maciej A Zwieniecki
- Department of Plant Sciences, University of California - Davis, Davis, CA, 95616, USA
| | - Francesca Secchi
- Department of Plant Sciences, University of California - Davis, Davis, CA, 95616, USA
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