Functional xylem characteristics associated with drought‐induced embolism in angiosperms

New Phytologist, Journal Year: 2022, Volume and Issue: 236(6), P. 2019 - 2036

Published: Aug. 30, 2022

Hydraulic failure resulting from drought-induced embolism in the xylem of plants is a key determinant reduced productivity and mortality. Methods to assess this vulnerability are difficult achieve at scale, leading alternative metrics correlations with more easily measured traits. These efforts have led longstanding pervasive assumed mechanistic link between vessel diameter angiosperms. However, there least two problems assumption that requires critical re-evaluation: (1) our current understanding does not provide explanation why increased width should lead greater vulnerability, (2) most recent advancements nanoscale processes suggest direct driver. Here, we review data physiological comparative wood anatomy studies, highlighting potential anatomical physicochemical drivers formation spread. We then put forward knowledge gaps, emphasising what known, unknown speculation. A meaningful evaluation diameter-vulnerability will require better biophysical level determine spread, which turn accurate predictions how water transport affected by drought.

Language: Английский

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Addressing controversies in the xylem embolism resistance–vessel diameter relationship

New Phytologist, Journal Year: 2023, Volume and Issue: 238(1), P. 283 - 296

Published: Jan. 13, 2023

Summary Although xylem embolism is a key process during drought‐induced tree mortality, its relationship to wood anatomy remains debated. While the functional link between bordered pits and resistance known, there no direct, mechanistic explanation for traditional assumption that wider vessels are more vulnerable than narrow ones. We used data from 20 temperate broad‐leaved species study inter‐ intraspecific of water potential at 50% loss conductivity ( P 50 ) with hydraulically weighted vessel diameter D h tested pit membrane thickness T PM specific K s on level. Embolism‐resistant had thick membranes vessels. was weakly associated , – remained highly significant after accounting . The interspecific pattern mirrored by but evidence an relationship. Our results provide robust across our species. As cause inconsistencies in published relationships, analysis suggests differences range trait values covered, level aggregation (species, or sample level) studied.

Language: Английский

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Neither xylem collapse, cavitation, or changing leaf conductance drive stomatal closure in wheat

Plant Cell & Environment, Journal Year: 2020, Volume and Issue: 43(4), P. 854 - 865

Published: Jan. 18, 2020

Abstract Identifying the drivers of stomatal closure and leaf damage during stress in grasses is a critical prerequisite for understanding crop resilience. Here, we investigated whether changes conductance ( g s ) dehydration were associated with hydraulic K ), xylem cavitation, collapse, cell turgor wheat Triticum aestivum ). During soil dehydration, decline was concomitant declining under mild water stress. This early not driven by as first cavitation events stem detected well after had declined. Xylem vessel deformation could only account <5% observed dehydration. Thus, concluded that tissues outside responsible majority wheat. However, contribution resistance to whole plant less than other (<35% resistance), this proportion remained constant plants dehydrated, indicating major driver closure.

Language: Английский

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Xylem Embolism Resistance Determines Leaf Mortality during Drought in Persea americana

PLANT PHYSIOLOGY, Journal Year: 2019, Volume and Issue: 182(1), P. 547 - 554

Published: Oct. 17, 2019

The driver of leaf mortality during drought stress is a critical unknown. We used the commercially important tree Persea americana, in which there large variation degree drought-induced death across canopy, to test whether embolism formation xylem drives this mortality. A range number embolized vessels petioles leaves was observed canopy plants that had experienced drought. Despite considerable between leaves, amount petiole strongly correlated with area tissue individual leaves. Consistent finding interleaf variability resistance embolism, 1.45 MPa water potential at 50% midrib Our results implicate as Moreover, we propose heterogeneity caused by high may act buffer against complete prolonged P. americana.

Language: Английский

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Evolutionary relationships between drought-related traits and climate shape large hydraulic safety margins in western North American oaks

Proceedings of the National Academy of Sciences, Journal Year: 2021, Volume and Issue: 118(10)

Published: March 1, 2021

Significance A fundamental association between sustained water transport and downstream tissue survival should select for xylem that avoids embolism in long-lived woody plants. Previous studies suggest long-vessel species, such as oaks vines, are more susceptible to drought-induced loss of function than other species. We show western North American oaks—even those occurring wet temperate forest—possess capable tolerating substantial stress. Evolutionary relationships drought tolerance traits combined with plant–climate interactions yield positive hydraulic safety margins from diverse habitats, demonstrating these key species not yet on the verge hydraulically mediated function. Quantifying physical limits desiccation is imperative predicting ecological consequences future droughts.

Language: Английский

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Mechanisms of xylem hydraulic recovery after drought in Eucalyptus saligna

Plant Cell & Environment, Journal Year: 2022, Volume and Issue: 45(4), P. 1216 - 1228

Published: Feb. 4, 2022

Abstract The mechanisms by which woody plants recover xylem hydraulic capacity after drought stress are not well understood, particularly with regard to the role of embolism refilling. We evaluated recovery in young Eucalyptus saligna exposed cycles and rewatering. Plants were moderate severe treatments, monitored at time intervals from 24 h 6 months percentage loss vessels due (PLV) was quantified each point using microcomputed tomography stem water potential (Ψ x ) canopy transpiration ( E c measured before scans. suffered high levels (47.38% ± 10.97% PLV) almost complete loss. No evidence refilling observed h, 1 week, or 3 weeks rewatering despite rapid Ψ . Recovery achieved over a 6‐month period growth new tissue, leaf area recovering same period. These findings indicate that E. recovers slowly stress, for persist many rainfall events.

Language: Английский

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Is xylem of angiosperm leaves less resistant to embolism than branches? Insights from microCT, hydraulics, and anatomy

Journal of Experimental Botany, Journal Year: 2018, Volume and Issue: unknown

Published: Aug. 30, 2018

According to the hydraulic vulnerability segmentation hypothesis, leaves are more vulnerable decline of conductivity than branches, but whether stem xylem is embolism resistant remains unclear. Drought-induced resistance leaf was investigated based on X-ray microcomputed tomography (microCT) for Betula pendula, Laurus nobilis, and Liriodendron tulipifera, excluding outside-xylem, compared with curves branch xylem. Moreover, bordered pit characters related were both organs. Theoretical P50 values (i.e. pressure corresponding 50% loss conductance) generally within same range as branches. similar branches L. tulipifera (-2.01 versus -2.10 MPa, respectively), negative B. pendula (-2.87 -1.80 MPa), less nobilis (-6.4 -9.2 MPa). Despite narrow conduits in mean interconduit membrane thickness organs, significantly higher This case study indicates that shows a largely across although differences organs may occur, suggesting interspecific variation regard hypothesis.

Language: Английский

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Vulnerability and hydraulic segmentations at the stem–leaf transition: coordination across Neotropical trees

New Phytologist, Journal Year: 2020, Volume and Issue: 228(2), P. 512 - 524

Published: June 4, 2020

Summary Hydraulic segmentation at the stem–leaf transition predicts higher hydraulic resistance in leaves than stems. Vulnerability segmentation, however, lower embolism leaves. Both mechanisms should theoretically favour runaway to preserve expensive organs such as stems, and be tested for any potential coordination. We investigated theoretical leaf‐specific conductivity based on an anatomical approach quantify degree of across 21 tropical rainforest tree species. Xylem stems (flow‐centrifugation technique) (optical visualization method) was quantified assess vulnerability segmentation. found a pervasive species, but with strong variability Despite clear continuum eight species showed positive (leaves less resistant stems), whereas remaining studied exhibited negative or no The positively related that segmented promote both hydraulically decouple leaf xylem from stem xylem. To what extent determine drought requires further integration leaf–stem whole‐plant level, including outer tissue.

Language: Английский

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A comparison of five methods to assess embolism resistance in trees

Forest Ecology and Management, Journal Year: 2020, Volume and Issue: 468, P. 118175 - 118175

Published: May 7, 2020

Language: Английский

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Wood structure and function change with maturity: Age of the vascular cambium is associated with xylem changes in current‐year growth

Plant Cell & Environment, Journal Year: 2019, Volume and Issue: 42(6), P. 1816 - 1831

Published: Feb. 1, 2019

Xylem vessel structure changes as trees grow and mature. Age- development-related in xylem are likely related to hydraulic function. We examined whether function, including conductivity vulnerability water-stress-induced embolism, changed over the course of cambial development stems 17 tree species. compared current-year growth young (1-4 years), intermediate (2-7 older (3-10 years) occurring series along branches. Diffuse ring porous species were examined, but nearly all produced only diffuse distal branches that irrespective their mature porosity type. Vessel diameter length increased with age. became both more conductive cavitation resistant Ring had longer wider vessels higher was vulnerable cavitation; however, these differences between types not present stem samples. Understanding plant function architecture requires sampling multiple-aged tissues because plants may vary considerably structural functional traits throughout body, even relatively short distances closely aged tissues.

Language: Английский

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