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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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Dutta S, Chen Z, Kaiser E, Matamoros PM, Steeneken PG, Verbiest GJ. Ultrasound Pulse Emission Spectroscopy Method to Characterize Xylem Conduits in Plant Stems. Research (Wash D C) 2022; 2022:9790438. [PMID: 36204251 PMCID: PMC9513830 DOI: 10.34133/2022/9790438] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 08/22/2022] [Indexed: 11/22/2022] Open
Abstract
Although it is well known that plants emit acoustic pulses under drought stress, the exact origin of the waveform of these ultrasound pulses has remained elusive. Here, we present evidence for a correlation between the characteristics of the waveform of these pulses and the dimensions of xylem conduits in plants. Using a model that relates the resonant vibrations of a vessel to its dimension and viscoelasticity, we extract the xylem radii from the waveforms of ultrasound pulses and show that these are correlated and in good agreement with optical microscopy. We demonstrate the versatility of the method by applying it to shoots of ten different vascular plant species. In particular, for Hydrangea quercifolia, we further extract vessel element lengths with our model and compare them with scanning electron cryomicroscopy. The ultrasonic, noninvasive characterization of internal conduit dimensions enables a breakthrough in speed and accuracy in plant phenotyping and stress detection.
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Affiliation(s)
- Satadal Dutta
- Department of Precision and Microsystems Engineering, Faculty of 3ME, TU Delft, Mekelweg 2, 2628CD Delft, Netherlands
| | - Zhiyi Chen
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, Netherlands
| | - Elias Kaiser
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, Netherlands
| | - Priscilla Malcolm Matamoros
- Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, Netherlands
| | - Peter G. Steeneken
- Department of Precision and Microsystems Engineering, Faculty of 3ME, TU Delft, Mekelweg 2, 2628CD Delft, Netherlands
| | - Gerard J. Verbiest
- Department of Precision and Microsystems Engineering, Faculty of 3ME, TU Delft, Mekelweg 2, 2628CD Delft, Netherlands
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Cory ST, Smith WK, Anderson TM. First-year Acacia seedlings are anisohydric "water-spenders" but differ in their rates of water use. AMERICAN JOURNAL OF BOTANY 2022; 109:1251-1261. [PMID: 35791878 PMCID: PMC9544296 DOI: 10.1002/ajb2.16032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
PREMISE First-year seedlings (FYS) of tree species may be a critical demographic bottleneck in semi-arid, seasonally dry ecosystems such as savannas. Given the highly variable water availability and potentially strong FYS-grass competition for water, FYS water-use strategies may play a crucial role in FYS establishment in savannas and, ultimately, in tree-grass competition and coexistence. METHODS We examined drought responses in FYS of two tree species that are dominant on opposite ends of an aridity gradient in Serengeti, Acacia (=Vachellia) tortilis and A. robusta. In a glasshouse experiment, gas exchange and whole-plant hydraulic conductance (Kplant ) were measured as soil water potential (Ψsoil ) declined. Trajectory of the Ψleaf /Ψsoil relationship during drought elucidated the degree of iso/anisohydry. RESULTS Both species were strongly anisohydric "water-spenders," allowing rapid wet-season C gain after pulses of moisture availability. Despite being equally vulnerable to declines in Kplant under severe drought, they differed in their rates of water use. Acacia tortilis, which occurs in the more arid regions, initially had greater Kmax , transpiration (E), and photosynthesis (Anet ) than A. robusta. CONCLUSIONS This work demonstrates an important mechanism of FYS establishment in savannas: Rather than investing in drought tolerance, savanna FYS maximize gas exchange during wet periods at the expense of desiccation during dry seasons. FYS establishment appears dependent on high C uptake during the pulses of water availability that characterize habitats dominated by these species. This study increases our understanding of species-scale plant ecophysiology and ecosystem-scale patterns of tree-grass coexistence.
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Affiliation(s)
- Scott T. Cory
- Department of BiologyWake Forest University1834 Wake Forest RoadWinston‐SalemNC27106USA
| | - William K. Smith
- Department of BiologyWake Forest University1834 Wake Forest RoadWinston‐SalemNC27106USA
| | - T. Michael Anderson
- Department of BiologyWake Forest University1834 Wake Forest RoadWinston‐SalemNC27106USA
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Lamacque L, Sabin F, Améglio T, Herbette S, Charrier G. Detection of acoustic events in lavender for measuring xylem vulnerability to embolism and cellular damage. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3699-3710. [PMID: 35176148 DOI: 10.1093/jxb/erac061] [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: 08/16/2021] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
Acoustic emission analysis is promising to investigate the physiological events leading to drought-induced injury and mortality. However, their nature and source are not fully understood, making this technique difficult to use as a direct measure of the loss of xylem hydraulic conductance. Acoustic emissions were recorded during severe dehydration in lavender plants (Lavandula angustifolia) and compared with the dynamics of embolism development and cell damage. The timing and characteristics of acoustic signals from two independent recording systems were compared by principal component analysis (PCA). Changes in water potential, branch diameter, loss of hydraulic conductance, and cellular damage were also measured to quantify drought-induced damages. Two distinct phases of acoustic emissions were observed during dehydration: the first one associated with a rapid loss of diameter and a significant increase in loss of xylem conductance (90%), and the second with slower changes in diameter and a significant increase in cellular damage. Based on PCA, a developed algorithm discriminated hydraulic-related acoustic signals from other sources, proposing a reconstruction of hydraulic vulnerability curves. Cellular damage preceded by hydraulic failure seems to lead to a lack of recovery. The second acoustic phase would allow detection of plant mortality.
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Affiliation(s)
- Lia Lamacque
- Université Clermont Auvergne, INRAE, PIAF, F-63000 Clermont-Ferrand, France
- Institut Technique Interprofessionnel Plantes à Parfum, Médicinal, Aromatiques et Industrielles, 26740 Montboucher-sur-Jabron, France
- CNRS Aix-Marseille University, France
| | - Florian Sabin
- Université Clermont Auvergne, INRAE, PIAF, F-63000 Clermont-Ferrand, France
| | - Thierry Améglio
- Université Clermont Auvergne, INRAE, PIAF, F-63000 Clermont-Ferrand, France
| | - Stéphane Herbette
- Université Clermont Auvergne, INRAE, PIAF, F-63000 Clermont-Ferrand, France
| | - Guillaume Charrier
- Université Clermont Auvergne, INRAE, PIAF, F-63000 Clermont-Ferrand, France
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Lauriks F, Salomón RL, De Roo L, Goossens W, Leroux O, Steppe K. Limited plasticity of anatomical and hydraulic traits in aspen trees under elevated CO2 and seasonal drought. PLANT PHYSIOLOGY 2022; 188:268-284. [PMID: 34718790 PMCID: PMC8774844 DOI: 10.1093/plphys/kiab497] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
The timing of abiotic stress elicitors on wood formation largely affects xylem traits that determine xylem efficiency and vulnerability. Nonetheless, seasonal variability of elevated CO2 (eCO2) effects on tree functioning under drought remains largely unknown. To address this knowledge gap, 1-year-old aspen (Populus tremula L.) trees were grown under ambient (±445 ppm) and elevated (±700 ppm) CO2 and exposed to an early (spring/summer 2019) or late (summer/autumn 2018) season drought event. Stomatal conductance and stem shrinkage were monitored in vivo as xylem water potential decreased. Additional trees were harvested for characterization of wood anatomical traits and to determine vulnerability and desorption curves via bench dehydration. The abundance of narrow vessels decreased under eCO2 only during the early season. At this time, xylem vulnerability to embolism formation and hydraulic capacitance during severe drought increased under eCO2. Contrastingly, stomatal closure was delayed during the late season, while hydraulic vulnerability and capacitance remained unaffected under eCO2. Independently of the CO2 treatment, elastic, and inelastic water pools depleted simultaneously after 50% of complete stomatal closure. Our results suggest that the effect of eCO2 on drought physiology and wood traits are small and variable during the growing season and question a sequential capacitive water release from elastic and inelastic pools as drought proceeds.
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Affiliation(s)
- Fran Lauriks
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Roberto Luis Salomón
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
- Grupo de Investigación Sistemas Naturales e Historia Forestal, Universidad Politécnica de Madrid, Madrid 28040, Spain
| | - Linus De Roo
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Willem Goossens
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Olivier Leroux
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
- Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
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Trabi CL, Pereira L, Guan X, Miranda MT, Bittencourt PRL, Oliveira RS, Ribeiro RV, Jansen S. A User Manual to Measure Gas Diffusion Kinetics in Plants: Pneumatron Construction, Operation, and Data Analysis. FRONTIERS IN PLANT SCIENCE 2021; 12:633595. [PMID: 34163496 PMCID: PMC8216216 DOI: 10.3389/fpls.2021.633595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/12/2021] [Indexed: 05/17/2023]
Abstract
The Pneumatron device measures gas diffusion kinetics in the xylem of plants. The device provides an easy, low-cost, and powerful tool for research on plant water relations and gas exchange. Here, we describe in detail how to construct and operate this device to estimate embolism resistance of angiosperm xylem, and how to analyse pneumatic data. Simple and more elaborated ways of constructing a Pneumatron are shown, either using wires, a breadboard, or a printed circuit board. The instrument is based on an open-source hardware and software system, which allows users to operate it in an automated or semi-automated way. A step-by-step manual and a troubleshooting section are provided. An excel spreadsheet and an R-script are also presented for fast and easy data analysis. This manual aims at helping users to avoid common mistakes, such as unstable measurements of the minimum and maximum amount of gas discharged from xylem tissue, which has major consequences for estimating embolism resistance. Major advantages of the Pneumatron device include its automated and accurate measurements of gas diffusion rates, including highly precise measurements of the gas volume in intact, embolised conduits. It is currently unclear if the method can also be applied to woody monocots, gymnosperm species that possess torus-margo pit membranes, or to herbaceous species.
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Affiliation(s)
| | - Luciano Pereira
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
- Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, Brazil
- Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Xinyi Guan
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - Marcela T. Miranda
- Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, Brazil
| | | | - Rafael S. Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Rafael V. Ribeiro
- Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
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Degraeve S, De Baerdemaeker NJF, Ameye M, Leroux O, Haesaert GJW, Steppe K. Acoustic Vulnerability, Hydraulic Capacitance, and Xylem Anatomy Determine Drought Response of Small Grain Cereals. FRONTIERS IN PLANT SCIENCE 2021; 12:599824. [PMID: 34113357 PMCID: PMC8186553 DOI: 10.3389/fpls.2021.599824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 04/12/2021] [Indexed: 06/01/2023]
Abstract
Selection of high-yielding traits in cereal plants led to a continuous increase in productivity. However, less effort was made to select on adaptive traits, favorable in adverse and harsh environments. Under current climate change conditions and the knowledge that cereals are staple foods for people worldwide, it is highly important to shift focus to the selection of traits related to drought tolerance, and to evaluate new tools for efficient selection. Here, we explore the possibility to use vulnerability to drought-induced xylem embolism of wheat cultivars Excalibur and Hartog (Triticum aestivum L.), rye cultivar Duiker Max (Secale cereale L.), and triticale cultivars Dublet and US2014 (x Triticosecale Wittmack) as a proxy for their drought tolerance. Multiple techniques were combined to underpin this hypothesis. During bench-top dehydration experiments, acoustic emissions (AEs) produced by formation of air emboli were detected, and hydraulic capacitances quantified. By only looking at the AE50 values, one would classify wheat cultivar Excalibur as most tolerant and triticale cultivar Dublet as most vulnerable to drought-induced xylem embolism, though Dublet had significantly higher hydraulic capacitances, which are essential in terms of internal water storage to temporarily buffer or delay water shortage. In addition, xylem anatomical traits revealed that both cultivars have a contrasting trade-off between hydraulic safety and efficiency. This paper emphasizes the importance of including a cultivar's hydraulic capacitance when evaluating its drought response and vulnerability to drought-induced xylem embolism, instead of relying on the AE50 as the one parameter.
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Affiliation(s)
- Szanne Degraeve
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Laboratory of Applied Mycology and Phenomics, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Niels J. F. De Baerdemaeker
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Maarten Ameye
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Laboratory of Applied Mycology and Phenomics, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Olivier Leroux
- Department of Biology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | | | - Kathy Steppe
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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8
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De Baerdemaeker NJF, Arachchige KNR, Zinkernagel J, Van den Bulcke J, Van Acker J, Schenk HJ, Steppe K. The stability enigma of hydraulic vulnerability curves: addressing the link between hydraulic conductivity and drought-induced embolism. TREE PHYSIOLOGY 2019; 39:1646-1664. [PMID: 31274162 DOI: 10.1093/treephys/tpz078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 03/29/2019] [Accepted: 06/13/2019] [Indexed: 05/29/2023]
Abstract
Maintaining xylem water transport under drought is vital for plants, but xylem failure does occur when drought-induced embolisms form and progressively spread through the xylem. The hydraulic method is widely considered the gold standard to quantify drought-induced xylem embolism. The method determines hydraulic conductivity (Kh) in cut branch samples, dehydrated to specific drought levels, by pushing water through them. The technique is widely considered for its reliable Kh measurements, but there is some uncertainty in the literature over how to define stable Kh and how that relates to the degree of xylem embolism formation. Therefore, the most common setup for this method was extended to measure four parameters: (i) inlet Kh, (ii) outlet Kh, (iii) radial flow from xylem to surrounding living tissue and (iv) the pressure difference across the sample. From a strictly theoretical viewpoint, hydraulic steady state, where inflow equals outflow and radial flow is zero, will result in stable Kh. Application of the setup to Malus domestica Borkh. branches showed that achieving hydraulic steady state takes considerable time (up to 300 min) and that time to reach steady state increased with declining xylem water potentials. During each experimental run, Kh and xylem water potentials dynamically increased, which was supported by X-ray computed microtomography visualizations of embolism refilling under both high- (8 kPa) and low-pressure (2 kPa) heads. Supplying pressurized water can hence cause artificial refilling of vessels, which makes it difficult to achieve a truly stable Kh in partially embolized xylem.
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Affiliation(s)
- Niels J F De Baerdemaeker
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | | | - Jana Zinkernagel
- Department of Vegetable Crops, Hochschule Geisenheim University, 65366 Geisenheim, Germany
| | - Jan Van den Bulcke
- UGCT-Laboratory of Wood Technology, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Joris Van Acker
- UGCT-Laboratory of Wood Technology, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - H Jochen Schenk
- Plants and H2O Laboratory, Department of Biological Science, California State University Fullerton, PO Box 6850, Fullerton, CA 92834-6850, USA
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
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Huber AE, Melcher PJ, Piñeros MA, Setter TL, Bauerle TL. Signal coordination before, during and after stomatal closure in response to drought stress. THE NEW PHYTOLOGIST 2019; 224:675-688. [PMID: 31364171 DOI: 10.1111/nph.16082] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/22/2019] [Indexed: 05/27/2023]
Abstract
Signal coordination in response to changes in water availability remains unclear, as does the role of embolism events in signaling drought stress. Sunflowers were exposed to two drought treatments of varying intensity while simultaneously monitoring changes in stomatal conductance, acoustic emissions (AE), turgor pressure, surface-level electrical potential, organ-level water potential and leaf abscisic acid (ABA) concentration. Leaf, stem and root xylem vulnerability to embolism were measured with the single vessel injection technique. In both drought treatments, it was found that AE events and turgor changes preceded the onset of stomatal closure, whereas electrical surface potentials shifted concurrently with stomatal closure. Leaf-level ABA concentration did not change until after stomata were closed. Roots and petioles were equally vulnerable to drought stress based on the single vessel injection technique. However, anatomical analysis of the xylem indicated that the increased AE events were not a result of xylem embolism formation. Additionally, roots and stems never reached a xylem pressure threshold that would initiate runaway embolism throughout the entire experiment. It is concluded that stomatal closure was not embolism-driven, but, rather, that onset of stomatal closure was most closely correlated with the hydraulic signal from changes in leaf turgor.
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Affiliation(s)
- Annika E Huber
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, NY, USA
| | - Peter J Melcher
- Biology Department, Center for Natural Sciences, Ithaca College, Ithaca, NY, 14850, NY, USA
| | - Miguel A Piñeros
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, NY, USA
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, 14853, NY, USA
| | - Tim L Setter
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, NY, USA
| | - Taryn L Bauerle
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, NY, USA
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10
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De Baerdemaeker NJF, Stock M, Van den Bulcke J, De Baets B, Van Hoorebeke L, Steppe K. X-ray microtomography and linear discriminant analysis enable detection of embolism-related acoustic emissions. PLANT METHODS 2019; 15:153. [PMID: 31889977 PMCID: PMC6916244 DOI: 10.1186/s13007-019-0543-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 12/05/2019] [Indexed: 05/08/2023]
Abstract
BACKGROUND Acoustic emission (AE) sensing is in use since the late 1960s in drought-induced embolism research as a non-invasive and continuous method. It is very well suited to assess a plant's vulnerability to dehydration. Over the last couple of years, AE sensing has further improved due to progress in AE sensors, data acquisition methods and analysis systems. Despite these recent advances, it is still challenging to detect drought-induced embolism events in the AE sources registered by the sensors during dehydration, which sometimes questions the quantitative potential of AE sensing. RESULTS In quest of a method to separate embolism-related AE signals from other dehydration-related signals, a 2-year-old potted Fraxinus excelsior L. tree was subjected to a drought experiment. Embolism formation was acoustically measured with two broadband point-contact AE sensors while simultaneously being visualized by X-ray computed microtomography (µCT). A machine learning method was used to link visually detected embolism formation by µCT with corresponding AE signals. Specifically, applying linear discriminant analysis (LDA) on the six AE waveform parameters amplitude, counts, duration, signal strength, absolute energy and partial power in the range 100-200 kHz resulted in an embolism-related acoustic vulnerability curve (VCAE-E) better resembling the standard µCT VC (VCCT), both in time and in absolute number of embolized vessels. Interestingly, the unfiltered acoustic vulnerability curve (VCAE) also closely resembled VCCT, indicating that VCs constructed from all registered AE signals did not compromise the quantitative interpretation of the species' vulnerability to drought-induced embolism formation. CONCLUSION Although machine learning could detect similar numbers of embolism-related AE as µCT, there still is insufficient model-based evidence to conclusively attribute these signals to embolism events. Future research should therefore focus on similar experiments with more in-depth analysis of acoustic waveforms, as well as explore the possibility of Fast Fourier transformation (FFT) to remove non-embolism-related AE signals.
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Affiliation(s)
- Niels J. F. De Baerdemaeker
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Michiel Stock
- KERMIT, Department of Data Analysis and Mathematical Modelling, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Jan Van den Bulcke
- UGent-Woodlab-Laboratory of Wood Technology, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
- Ghent University Centre for X-Ray Tomography (UGCT), Proeftuinstraat 86, 9000 Ghent, Belgium
| | - Bernard De Baets
- KERMIT, Department of Data Analysis and Mathematical Modelling, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Luc Van Hoorebeke
- Ghent University Centre for X-Ray Tomography (UGCT), Proeftuinstraat 86, 9000 Ghent, Belgium
- Radiation Physics Group, Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
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11
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Klein T, Zeppel MJB, Anderegg WRL, Bloemen J, De Kauwe MG, Hudson P, Ruehr NK, Powell TL, von Arx G, Nardini A. Xylem embolism refilling and resilience against drought-induced mortality in woody plants: processes and trade-offs. Ecol Res 2018. [DOI: 10.1007/s11284-018-1588-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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12
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Scoffoni C, Sack L, Ort D. The causes and consequences of leaf hydraulic decline with dehydration. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4479-4496. [PMID: 28981777 DOI: 10.1093/jxb/erx252] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Resolving the drivers of hydraulic decline during drought is crucial for understanding drought tolerance in crops and natural ecosystems. In the past 15 years, studies of the decline of leaf hydraulic conductance (Kleaf) have supported a major role in controlling plant drought responses. We analyzed the variation in Kleaf decline with dehydration in a global database of 310 species, providing novel insights into its underlying mechanisms, its co-ordination with stem hydraulics, its influence on gas exchange and drought tolerance, and its linkage with species ecological distributions. Kleaf vulnerability varied strongly within and across lineages, growth forms, and biomes. A critical literature review indicates that changes in hydraulic conductance outside the xylem with dehydration drive the overall decline of Kleaf. We demonstrate a significant leaf hydraulic safety-efficiency trade-off across angiosperm species and discuss the importance of the large variation around this trend. Leaves tend to be more vulnerable than stems, with their vulnerabilities co-ordinated across species, and importantly linked with adaptation across biomes. We hypothesize a novel framework to explain diversity across species in the co-ordination of Kleaf and gas exchange during dehydration. These findings reflect considerable recent progress, yet new tools for measurement, visualization, and modeling will result in ongoing discoveries important across fields in plant biology.
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Affiliation(s)
- Christine Scoffoni
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA 90095, USA
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA 90095, USA
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Kratochvil HG, Pollirer M. Acoustic effects during photosynthesis of aquatic plants enable new research opportunities. Sci Rep 2017; 7:44526. [PMID: 28291222 PMCID: PMC5349586 DOI: 10.1038/srep44526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 02/10/2017] [Indexed: 11/10/2022] Open
Abstract
Measurements of photosynthetic processes in hydrophytes mostly involve photosynthometers, which capture the escaping gas for subsequent analysis The most common method to detect changes in the rate of photosynthetic processes is to count the series of escaping gas bubbles. The emerging bubbles are either simply counted or they are recorded using light barriers, which is very difficult because of their small size and often varying ascent rate. The gas bubbles generated during photosynthesis by aquatic plants produce distinctive sound pulses when leaving the plants. These acoustic side effects enable completely new and highly accurate measurements. The frequency and reaction time changes of the pulses caused by external influences are therefore accurately detectable. The precise time measurements enable registering and evaluating the curves as reactions to changes in physical or chemical environmental conditions. We show that such acoustic analyses open completely new research opportunities for plant physiology.
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Affiliation(s)
- Helmut G Kratochvil
- Dep. Integrative Zoologie, University of Vienna, Althanstr. 14, A-1090 Wien, Austria
| | - Michael Pollirer
- Dep. Integrative Zoologie, University of Vienna, Althanstr. 14, A-1090 Wien, Austria
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14
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Nardini A, Savi T, Losso A, Petit G, Pacilè S, Tromba G, Mayr S, Trifilò P, Lo Gullo MA, Salleo S. X-ray microtomography observations of xylem embolism in stems of Laurus nobilis are consistent with hydraulic measurements of percentage loss of conductance. THE NEW PHYTOLOGIST 2017; 213:1068-1075. [PMID: 27735069 DOI: 10.1111/nph.14245] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 09/02/2016] [Indexed: 06/06/2023]
Abstract
Drought-induced xylem embolism is a serious threat to plant survival under future climate scenarios. Hence, accurate quantification of species-specific vulnerability to xylem embolism is a key to predict the impact of climate change on vegetation. Low-cost hydraulic measurements of embolism rate have been suggested to be prone to artefacts, thus requiring validation by direct visualization of the functional status of xylem conduits using nondestructive imaging techniques, such as X-ray microtomography (microCT). We measured the percentage loss of conductance (PLC) of excised stems of Laurus nobilis (laurel) dehydrated to different xylem pressures, and compared results with direct observation of gas-filled vs water-filled conduits at a synchrotron-based microCT facility using a phase contrast imaging modality. Theoretical PLC calculated on the basis of microCT observations in stems of laurel dehydrated to different xylem pressures overall were in agreement with hydraulic measurements, revealing that this species suffers a 50% loss of xylem hydraulic conductance at xylem pressures averaging -3.5 MPa. Our data support the validity of estimates of xylem vulnerability to embolism based on classical hydraulic techniques. We discuss possible causes of discrepancies between data gathered in this study and those of recent independent reports on laurel hydraulics.
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Affiliation(s)
- Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Tadeja Savi
- 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
| | - Giai Petit
- Dipartimento Territorio e Sistemi Agro-forestali, Università degli Studi di Padova, Viale dell'Università 16, 35020, Legnaro (PD), Italy
| | - Serena Pacilè
- Dipartimento di Ingegneria e Architettura, Università di Trieste, Piazzale Europa 1, 34127, Trieste, Italy
- Elettra-Sincrotrone Trieste, Area Science Park, 34149, Basovizza, 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
| | - Patrizia Trifilò
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche e Ambientali, Università di Messina, Salita F. Stagno D'Alcontres 31, 98166, Messina, 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
| | - Sebastiano Salleo
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy
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15
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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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16
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Vergeynst LL, Sause MGR, De Baerdemaeker NJF, De Roo L, Steppe K. Clustering reveals cavitation-related acoustic emission signals from dehydrating branches. TREE PHYSIOLOGY 2016; 36:786-96. [PMID: 27095256 DOI: 10.1093/treephys/tpw023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 01/31/2016] [Indexed: 05/23/2023]
Abstract
The formation of air emboli in the xylem during drought is one of the key processes leading to plant mortality due to loss in hydraulic conductivity, and strongly fuels the interest in quantifying vulnerability to cavitation. The acoustic emission (AE) technique can be used to measure hydraulic conductivity losses and construct vulnerability curves. For years, it has been believed that all the AE signals are produced by the formation of gas emboli in the xylem sap under tension. More recent experiments, however, demonstrate that gas emboli formation cannot explain all the signals detected during drought, suggesting that different sources of AE exist. This complicates the use of the AE technique to measure emboli formation in plants. We therefore analysed AE waveforms measured on branches of grapevine (Vitis vinifera L. 'Chardonnay') during bench dehydration with broadband sensors, and applied an automated clustering algorithm in order to find natural clusters of AE signals. We used AE features and AE activity patterns during consecutive dehydration phases to identify the different AE sources. Based on the frequency spectrum of the signals, we distinguished three different types of AE signals, of which the frequency cluster with high 100-200 kHz frequency content was strongly correlated with cavitation. Our results indicate that cavitation-related AE signals can be filtered from other AE sources, which presents a promising avenue into quantifying xylem embolism in plants in laboratory and field conditions.
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Affiliation(s)
- Lidewei L Vergeynst
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Markus G R Sause
- Experimental Physics II, Institute for Physics, University of Augsburg, D-86135 Augsburg, Germany
| | - Niels J F De Baerdemaeker
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Linus De Roo
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Applied Ecology and Environmental Biology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
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17
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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: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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18
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Brodribb TJ, Skelton RP, McAdam SAM, Bienaimé D, Lucani CJ, Marmottant P. Visual quantification of embolism reveals leaf vulnerability to hydraulic failure. THE NEW PHYTOLOGIST 2016; 209:1403-9. [PMID: 26742653 DOI: 10.1111/nph.13846] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 12/08/2015] [Indexed: 05/13/2023]
Abstract
Vascular plant mortality during drought has been strongly linked to a failure of the internal water transport system caused by the rapid invasion of air and subsequent blockage of xylem conduits. Quantification of this critical process is greatly complicated by the existence of high water tension in xylem cells making them prone to embolism during experimental manipulation. Here we describe a simple new optical method that can be used to record spatial and temporal patterns of embolism formation in the veins of water-stressed leaves for the first time. Applying this technique in four diverse angiosperm species we found very strong agreement between the dynamics of embolism formation during desiccation and decline of leaf hydraulic conductance. These data connect the failure of the leaf water transport network under drought stress to embolism formation in the leaf xylem, and suggest embolism occurs after stomatal closure under extreme water stress.
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Affiliation(s)
- Timothy J Brodribb
- School of Biological Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Robert P Skelton
- School of Biological Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Scott A M McAdam
- School of Biological Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Diane Bienaimé
- LIPhy UMR 5588, CNRS/Université Grenoble-Alpes, Grenoble, F-38401, France
| | - Christopher J Lucani
- School of Biological Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
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