Mechanisms of woody-plant mortality under rising drought, CO2 and vapour pressure deficit

Nature Reviews Earth & Environment, Journal Year: 2022, Volume and Issue: 3(5), P. 294 - 308

Published: March 29, 2022

Language: Английский

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Water uptake depth is coordinated with leaf water potential, water‐use efficiency and drought vulnerability in karst vegetation

New Phytologist, Journal Year: 2020, Volume and Issue: 229(3), P. 1339 - 1353

Published: Sept. 29, 2020

Root access to bedrock water storage or groundwater is an important trait allowing plant survival in seasonally dry environments. However, the degree of coordination between uptake depth, leaf-level water-use efficiency (WUEi) and potential drought-prone communities not well understood. We conducted a 135-d rainfall exclusion experiment subtropical karst ecosystem with thin skeletal soils evaluate responses 11 co-occurring woody species contrasting life forms leaf habits severe drought during wet growing season. Marked differences xylem isotopic composition revealed distinct ecohydrological niche separation among species. The behaviour coexisting was largely explained by root deeper, temporally stable sources. Smaller-diameter shallower uptake, more negative potentials lower WUEi showed extensive drought-induced canopy defoliation and/or mortality. By contrast, larger-diameter deeper higher isohydric survived only moderate defoliation. Severe limitation imposes strong environmental filtering selective pressures resulting tight tree diameter, iso/anisohydric behaviour, vulnerability communities.

Language: Английский

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Lack of hydraulic recovery as a cause of post‐drought foliage reduction and canopy decline in European beech

New Phytologist, Journal Year: 2022, Volume and Issue: 234(4), P. 1195 - 1205

Published: March 3, 2022

European beech (Fagus sylvatica) was among the most affected tree species during severe 2018 drought. It not only suffered from instant physiological stress but also showed symptoms of defoliation and canopy decline in following year. To explore underlying mechanisms, we used Swiss-Canopy-Crane II site studied branches healthy symptomatic trees repair hydraulic function concentration carbohydrates drought 2019. We found loss conductance 2018, which did recover 2019 that developed year after Reduced branch foliation associated with a gradual wood starch throughout summer Visualization water transport confirmed close relationship between xylem functionality supported leaf area. Our findings embolized does regain season sustained dysfunction is counterbalanced by reduction suggests acclimation development to mitigate disturbances function.

Language: Английский

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Linking xylem network failure with leaf tissue death

New Phytologist, Journal Year: 2021, Volume and Issue: 232(1), P. 68 - 79

Published: June 24, 2021

Summary 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 process connecting atmospheric drying plant tissue damage. Recent episodes worldwide have been widely attributed dry conditions causing acute damage vascular systems. Under scenario embolisms produced by water stress are thought cause death, yet hypothetical trajectory has never empirically demonstrated. Here we provide foundational evidence failure in network leaves with caused during stress. We observe a catastrophic sequence initiated column breakage under tension leaf veins which severs local supply, immediately cellular dehydration irreversible By highlighting primacy death exposed or evaporative our results strong mechanistic foundation upon models response can be confidently structured.

Language: Английский

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Abscisic Acid Biosynthesis and Signaling in Plants: Key Targets to Improve Water Use Efficiency and Drought Tolerance

Applied Sciences, Journal Year: 2020, Volume and Issue: 10(18), P. 6322 - 6322

Published: Sept. 11, 2020

The observation of a much-improved fitness wild-type plants over abscisic acid (ABA)-deficient mutants during drought has led researchers from all to world perform experiments aiming at better understanding how this hormone modulates the physiology under water-limited conditions. More recently, several promising approaches manipulating ABA biosynthesis and signaling have been explored improve water use efficiency confer tolerance major crop species. Here, we review recent progress made in last decade on (i) biosynthesis, (ii) roles plant-water relations primary secondary metabolisms drought, (iii) regulation levels perception

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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Stomatal evolution and plant adaptation to future climate

Plant Cell & Environment, Journal Year: 2024, Volume and Issue: 47(9), P. 3299 - 3315

Published: May 16, 2024

Global climate change is affecting plant photosynthesis and transpiration processes, as well increasing weather extremes impacting socio-political environmental events decisions for decades to come. One major research challenge in biology ecology the interaction of with environment. Stomata control gas exchange their evolution was a crucial innovation that facilitated earliest land plants colonize terrestrial environments. couple homoiohydry, together cuticles, intercellular space, endohydric water-conducting system, enabling adapt diversify across planet. Plants stomatal movement response through regulating guard cell turgor mediated by membrane transporters signaling transduction. However, origin, evolution, active stomata remain controversial topics. We first review diversity, providing fossil phylogenetic evidence origins. summarize functional context changes stresses. Our analyses show core elements are more ancient than stomata, while genes involved development co-evolved de novo stomata. These results suggest novel development-specific were acquired during whereas movement, especially pathways, inherited ancestrally co-opted dynamic differentiation. two processes reflect different adaptation strategies evolution.

Language: Английский

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Linking water‐use strategies with drought resistance across herbaceous crops

Physiologia Plantarum, Journal Year: 2024, Volume and Issue: 176(1)

Published: Jan. 1, 2024

Abstract Woody plants minimize xylem embolism formation during drought essentially by closing stomata at higher water potentials and/or increasing the resistance to embolism. Both of these mechanisms result in a stomatal safety margin (SSM), which is potential difference between closure and formation. Here, we investigated whether SSM represents mechanism for herbaceous how different water‐use strategies impact their survival. For that, exposed four crops with contrasting severe deficit assess drought‐induced damage mortality. Unlike woody species, was not associated plant survival crops. Soybean, presented largest across (1.67 MPa), exhibited earliest mortality leaves whole as well highest rate (100%) end period. Cowpea, an 0.63 MPa, most drought‐resistant latest leaf (100%). The effective traits ensuring under were those related avoidance such (1) early closure, (2) very low residual transpiration post‐stomatal (3) high capacitance pre‐ post‐turgor loss.

Language: Английский

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Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress

Frontiers in Plant Science, Journal Year: 2021, Volume and Issue: 12

Published: Sept. 3, 2021

During drought, trees reduce water loss and hydraulic failure by closing their stomata, which also limits photosynthesis. Under severe drought stress, other acclimation mechanisms are trigged to further transpiration prevent irreversible conductance loss. Here, we investigate two of them: the reversible impacts on photosynthetic apparatus, lumped as non-stomatal limitations (NSL) photosynthesis, effect premature leaf shedding. We integrate NSL shedding with a state-of-the-art tree simulation model (SOX+) parameterize them example field measurements demonstrate stress-mitigating impact these processes. measured xylem vulnerability, transpiration, litter fall dynamics in Pinus sylvestris (L.) saplings grown for 54 days under dry-down. The observations showed that, once stopped, rate strongly increased until about 30% area was lost average. trained SOX+ simulated changes root-to-canopy without including Accounting improved representation while projections were reduced an overall 6%. Together, observed projected losses 13%. In summary, results highlight importance than purely stomatal conductance-driven adjustments resistance Scots pine. responses such morphological (leaf shedding) physiological adjustments, has potential improve models, particularly when applied predicting drought-induced mortality.

Language: Английский

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Abscisic acid acts essentially on stomata, not on the xylem, to improve drought resistance in tomato

Plant Cell & Environment, Journal Year: 2023, Volume and Issue: 46(11), P. 3229 - 3241

Published: Aug. 1, 2023

Drought resistance is essential for plant production under water-limiting environments. Abscisic acid (ABA) plays a critical role in stomata but its impact on hydraulic function beyond the far less studied. We selected genotypes differing their ability to accumulate ABA investigate drought-induced dysfunction. All exhibited similar leaf and stem embolism regardless of differences levels. Their was also similar. Differences were only observed between two extreme genotypes: sitiens (sit; strong ABA-deficient mutant) sp12 (a transgenic line that constitutively overaccumulates ABA), where water potential inducing 50% 0.25 MPa lower than sit. Maximum stomatal minimum conductances considerably plants with higher (wild type [WT] sp12) mutants. Variations gas exchange across associated levels density size. The loss meant lethal potentials occurred later during drought plants, followed by WT, then Therefore, primary pathway which enhances via declines loss, delays dehydration

Language: Английский

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