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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The relative area of vessels in xylem correlates with stem embolism resistance within and between genera

Tree Physiology, Journal Year: 2022, Volume and Issue: 43(1), P. 75 - 87

Published: Sept. 7, 2022

The resistance of xylem conduits to embolism is a major factor defining drought tolerance and can set the distributional limits species across rainfall gradients. Recent work suggests that proximity vessels neighbors increases vulnerability conduit. We therefore investigated whether relative vessel area correlates with intra- inter-generic variation in pairs or triplets from genera Acer, Cinnamomum, Ilex, Quercus Persea, adapted environments differing aridity. used optical method assess stems conducted anatomical measurements on which was quantified. Vessel lumen fraction (VLF) correlated within genera. A low VLF likely gas movement between conduits, by diffusion advection, whereas high enhances transport thorough increased conduit-to-conduit connectivity reduced distances likelihood propagation. suggest rate due local pressure differences network central driver propagation angiosperm vessels.

Language: Английский

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Optimal balancing of xylem efficiency and safety explains plant vulnerability to drought

Ecology Letters, Journal Year: 2023, Volume and Issue: 26(9), P. 1485 - 1496

Published: June 17, 2023

In vast areas of the world, forests and vegetation are water limited plant survival depends on ability to avoid catastrophic hydraulic failure. Therefore, it is remarkable that plants take risks by operating at potentials (ψ) induce partial failure conduits (xylem). Here we present an eco-evolutionary optimality principle for xylem conduit design explains this phenomenon based hypothesis conductive efficiency safety optimally co-adapted environment. The model relationship between tolerance negative potential (ψ50 ) environmentally dependent minimum ψ (ψmin across a large number species, along pathway within individuals two species studied. wider margin in gymnosperms compared angiosperms can be explained as adaptation higher susceptibility accumulation embolism. provides novel optimality-based perspective efficiency.

Language: Английский

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Pit characters determine drought-induced embolism resistance of leaf xylem across 18 Neotropical tree species

PLANT PHYSIOLOGY, Journal Year: 2022, Volume and Issue: 190(1), P. 371 - 386

Published: May 10, 2022

Embolism spreading in xylem is an important component of plant drought resistance. Since embolism resistance has been shown to be mechanistically linked pit membrane characters stem xylem, we speculate that similar mechanisms account for leaf xylem. We conducted transmission electron microscopy investigate across 18 Neotropical tree species. also gold perfusion and polar lipid detection experiments on three species covering the full range then related these observations previously published data incorporated membranes link between vulnerability segmentation (i.e. difference resistance) leaf-stem anatomical variation. Maximum thickness (Tpm,max) thickness-to-diameter ratio (Tpm,max/Dpm) were predictive resistance, especially when vestured pits taken into account. Variation Tpm,max/Dpm was only trait leaves stems. Gold particles 5- 10-nm infiltrated species, while entry 50-nm blocked. Moreover, lipids associated with inner conduit walls pits. Our results suggest are determined by Tpm, pore constrictions narrowest bottlenecks along pathways), surfactants, which largely temperate tropical trees. However, our mechanistic understanding propagation functional relevance remains elusive.

Language: Английский

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A unit pipe pneumatic model to simulate gas kinetics during measurements of embolism in excised angiosperm xylem

Tree Physiology, Journal Year: 2022, Volume and Issue: 43(1), P. 88 - 101

Published: Sept. 1, 2022

Abstract The pneumatic method has been introduced to quantify embolism resistance in plant xylem of various organs by applying a partial vacuum cut-open xylem. Despite the similarity vulnerability curves between and other methods, modeling approach is needed investigate if changes during dehydration can be accurately quantified based on gas diffusion kinetics. Therefore, unit pipe (UPPn) model was developed estimate extraction from intact conduits, which were axially interconnected inter-conduit pit membranes conduits. physical laws used included Fick’s law for diffusion, Henry’s concentration partitioning liquid phases at equilibrium ideal law. UPPn showed that 91% extracted came first five series embolized, conduits only 9% aqueous phase after 15 s simulation. Considering alternative sources, measured with pneumatron device systematically overestimated 2–17%, corresponded typical measuring error 0.11 MPa P50 (the water potential equivalent 50% maximum amount extracted). It concluded directly measure due fast movement across interconduit membranes, while sap hydrated cell walls about 100 times slower. We expect will also contribute understanding propagation temporal dynamics.

Language: Английский

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A Systems Approach to Understanding How Plants Transformed Earth's Environment in Deep Time

Annual Review of Earth and Planetary Sciences, Journal Year: 2023, Volume and Issue: 51(1), P. 551 - 580

Published: May 31, 2023

Terrestrial plants have transformed Earth's surface environments by altering water, energy, and biogeochemical cycles. Studying vegetation-climate interaction in deep time has necessarily relied on modern-plant analogs to represent paleo-ecosystems—as methods for reconstructing paleo- and, particular, extinct-plant function were lacking. This approach is potentially compromised given that plant physiology evolved through time, some paleo-plants no clear modern analog. Advancements the quantitative reconstruction of whole-plant provide new opportunities replace capture age-specific interactions. Here, we review recent investigations paleo-plant performance integration fossil geologic data with process-based ecosystem- Earth system–scale models explore how early vascular responded influenced climate. First, present an argument characterizing extinct terms ecological evolutionary theory a framework advancing reconstructed interactions time. We discuss novel mechanistic understanding provided applying these approaches late Paleozoic ever-wet tropics at higher latitudes. Finally, preliminary applications state-of-the-art system model highlight potential implications different functional strategies our ▪For hundreds millions years, been keystone maintaining status atmosphere, oceans, climate.▪Extinct functioned differently across limiting processes interact produce climate.▪New methods, reviewed here, allow based record.▪Integrating into ecosystem climate will expand vegetation's role past environmental change.

Language: Английский

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Angiosperms follow a convex trade‐off to optimize hydraulic safety and efficiency

New Phytologist, Journal Year: 2023, Volume and Issue: 240(5), P. 1788 - 1801

Published: Sept. 10, 2023

Intervessel pits are considered to function as valves that avoid embolism spreading and optimize efficient transport of xylem sap across neighbouring vessels. Hydraulic between vessels would therefore follow a safety-efficiency trade-off, which is directly related the total intervessel pit area (Ap ), inversely membrane thickness (TPM ) driven by pressure difference. To test this hypothesis, we modelled relative rate gas (ka water (Q) at level for 23 angiosperm species correlated these parameters with potential 50% occurs (Ψ50 ). We also measured ka 10 using pneumatic measurements. The difference adjacent estimated values Q were Ψ50 , following convex trade-off based on experimental data. Minor changes in TPM Ap exponentially affected flow, respectively. Our results provide clear evidence not linear, but due flow membranes, represent mesoporous media within microporous conduits. Moreover, nature long-distance may contribute an adjustable fluid balance plants, depending environmental conditions.

Language: Английский

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Gradients in embolism resistance within stems driven by secondary growth in herbs

Plant Cell & Environment, Journal Year: 2024, Volume and Issue: 47(8), P. 2986 - 2998

Published: April 21, 2024

Abstract The stems of some herbaceous species can undergo basal secondary growth, leading to a continuum in the degree woodiness along stem. Whether formation growth stem base results differences embolism resistance between and upper portions is unknown. We assessed leaves simultaneously within same individuals two divergent that mature bases. were Solanum lycopersicum (tomato) Senecio minimus (fireweed). Basal plants both displayed advanced greater than This also resulted significant vulnerability segmentation species. Greater woodier was found alongside decreases pith‐to‐xylem ratio, increases proportion xylem, lignin content. show there be considerable variation across herbs this linked present. A gradient could an adaptation ensure reproduction or resprouting during episodes drought late lifecycle.

Language: Английский

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Contrasts in hydraulics underlie the divergent performances of Populus and native tree species in water‐limited sandy land environments

Physiologia Plantarum, Journal Year: 2025, Volume and Issue: 177(1)

Published: Jan. 1, 2025

Abstract Populus tree species are commonly used for creating shelter forests in vast areas of northern China, at least partially due to their fast growth. However, they facing severe problems decline and mortality caused by drought. In contrast, native water‐limited environments usually have slow growth currently not afforestation, while these gaining more attention forestry greater resilience Horqin Sandy Land, we conducted a comparative analysis xylem hydraulics associated physiological traits between six drought‐prone areas. Compared the species, exhibited significantly higher stem hydraulic conductivity but lower resistance drought‐induced embolism than species. The observed interspecific variations contrasts two groups were predominantly attributed anatomical characteristics pit level rather tissue level. line with divergences hydraulics, found intrinsic water use efficiency (WUE i ) suggesting that adopted relatively acquisitive conservative strategies, respectively. trade‐off safety, as well WUE , underlies performance is, high risk dysfunction when drought, vice versa.

Language: Английский

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Gas diffusion kinetics in relation to embolism formation and propagation in angiosperm xylem: a mini-review

Acta Horticulturae, Journal Year: 2025, Volume and Issue: 1419, P. 123 - 134

Published: Feb. 1, 2025

Language: Английский

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