Mechanisms of plant survival and mortality during drought: why do some plants survive while others succumb to drought?

New Phytologist, Journal Year: 2008, Volume and Issue: 178(4), P. 719 - 739

Published: April 14, 2008

Summary Severe droughts have been associated with regional‐scale forest mortality worldwide. Climate change is expected to exacerbate regional events; however, prediction remains difficult because the physiological mechanisms underlying drought survival and are poorly understood. We developed a hydraulically based theory considering carbon balance insect resistance that allowed development examination of hypotheses regarding mortality. Multiple may cause during drought. A common mechanism for plants isohydric regulation water status results from avoidance drought‐induced hydraulic failure via stomatal closure, resulting in starvation cascade downstream effects such as reduced biotic agents. Mortality by per se occur seedlings or trees near their maximum height. Although anisohydric relatively drought‐tolerant, they predisposed operate narrower safety margins Elevated temperatures should failure. Biotic agents amplify be amplified plant stress. Wet multidecadal climate oscillations increase susceptibility stimulating shifts architecture, effectively predisposing warming increased frequency extreme events will probably episodes. Isohydric potential partition species between mortality, and, such, incorporating this framework effective modeling under future conditions. Contents 1 I. Introduction 2 II. Consequences vegetation 3 III. Global patterns IV. Hypotheses on drought‐related 4 V. Evidence hypothesized 5 VI. Implications 13 VII. Conclusions 15 Acknowledgements References

Language: Английский

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Plant Ecological Strategies: Some Leading Dimensions of Variation Between Species

Annual Review of Ecology and Systematics, Journal Year: 2002, Volume and Issue: 33(1), P. 125 - 159

Published: Nov. 1, 2002

▪ Abstract An important aim of plant ecology is to identify leading dimensions ecological variation among species and understand the basis for them. Dimensions that can readily be measured would especially useful, because they might offer a path towards improved worldwide synthesis across thousands field experiments ecophysiological studies use just few each. Four are reviewed here. The leaf mass per area–leaf lifespan (LMA-LL) dimension expresses slow turnover parts (at high LMA long LL), nutrient residence times, response favorable growth conditions. seed mass–seed output (SM-SO) an predictor dispersal establishment opportunities (seed output) success in face hazards mass). LMA-LL SM-SO each underpinned by single, comprehensible tradeoff, their consequences fairly well understood. size–twig size (LS-TS) spectrum has obvious texture canopies, but costs benefits large versus small twig poorly height universally been seen as ecologically included strategy schemes. Nevertheless, includes several tradeoffs adaptive elements, which ideally should treated separately. Each these four varies at scales climate zones site types within landscapes. This interpreted adaptation physical environment. also widely coexisting species. Most likely this within-site arises depend strongly on other present, words, set stable mixture strategies.

Language: Английский

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On underestimation of global vulnerability to tree mortality and forest die‐off from hotter drought in the Anthropocene

Ecosphere, Journal Year: 2015, Volume and Issue: 6(8), P. 1 - 55

Published: Aug. 1, 2015

Patterns, mechanisms, projections, and consequences of tree mortality associated broad‐scale forest die‐off due to drought accompanied by warmer temperatures—“hotter drought”, an emerging characteristic the Anthropocene—are focus rapidly expanding literature. Despite recent observational, experimental, modeling studies suggesting increased vulnerability trees hotter pests pathogens, substantial debate remains among research, management policy‐making communities regarding future risks. We summarize key mortality‐relevant findings, differentiating between those implying lesser versus greater levels vulnerability. Evidence includes benefits elevated [CO 2 ] water‐use efficiency; observed modeled increases in growth canopy greening; widespread woody‐plant biomass, density, extent; compensatory physiological, morphological, genetic mechanisms; dampening ecological feedbacks; potential mitigation management. In contrast, document more rapid under negative physiological responses accelerated biotic attacks. Additional evidence rising background rates; projected frequency, intensity, duration; limitations vegetation models such as inadequately represented processes; warming feedbacks from die‐off; wildfire synergies. Grouping these findings we identify ten contrasting perspectives that shape but have not been discussed collectively. also present a set global drivers are known with high confidence: (1) droughts eventually occur everywhere; (2) produces droughts; (3) atmospheric moisture demand nonlinearly temperature during drought; (4) can faster drought, consistent fundamental physiology; (5) shorter frequently than longer become lethal warming, increasing frequency nonlinearly; (6) happens relative intervals needed for recovery. These high‐confidence drivers, concert research supporting perspectives, support overall viewpoint globally. surmise is being discounted part difficulties predicting threshold extreme climate events. Given profound societal implications underestimating highlight urgent challenges management, communities.

Language: Английский

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Plant Immunity to Insect Herbivores

Annual Review of Plant Biology, Journal Year: 2007, Volume and Issue: 59(1), P. 41 - 66

Published: Nov. 22, 2007

Herbivorous insects use diverse feeding strategies to obtain nutrients from their host plants. Rather than acting as passive victims in these interactions, plants respond herbivory with the production of toxins and defensive proteins that target physiological processes insect. Herbivore-challenged also emit volatiles attract insect predators bolster resistance future threats. This highly dynamic form immunity is initiated by recognition oral secretions signals injured plant cells. These initial cues are transmitted within signal transduction pathways include calcium ion fluxes, phosphorylation cascades, and, particular, jasmonate pathway, which plays a central conserved role promoting broad spectrum insects. A detailed understanding arthropod herbivores will provide new insights into basic mechanisms chemical communication plant-animal coevolution may facilitate approaches crop protection improvement.

Language: Английский

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The interaction of plant biotic and abiotic stresses: from genes to the field

Journal of Experimental Botany, Journal Year: 2012, Volume and Issue: 63(10), P. 3523 - 3543

Published: March 30, 2012

Plant responses to different stresses are highly complex and involve changes at the transcriptome, cellular, physiological levels. Recent evidence shows that plants respond multiple differently from how they do individual stresses, activating a specific programme of gene expression relating exact environmental conditions encountered. Rather than being additive, presence an abiotic stress can have effect reducing or enhancing susceptibility biotic pest pathogen, vice versa. This interaction between is orchestrated by hormone signalling pathways may induce antagonize one another, in particular abscisic acid. Specificity further controlled range molecular mechanisms act together regulatory network. Transcription factors, kinase cascades, reactive oxygen species key components this cross-talk, as heat shock factors small RNAs. review aims characterize level, focusing on important both pathways. Identifying master regulators connect response fundamental providing opportunities for developing broad-spectrum stress-tolerant crop plants.

Language: Английский

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The plant traits that drive ecosystems: Evidence from three continents

Journal of Vegetation Science, Journal Year: 2004, Volume and Issue: 15(3), P. 295 - 304

Published: Feb. 24, 2004

Abstract Question: A set of easily‐measured (‘soft’) plant traits has been identified as potentially useful predictors ecosystem functioning in previous studies. Here we aimed to discover whether the screening techniques remain operational widely contrasted circumstances, test for existence axes variation particular sets traits, and their links with ‘harder’ proven importance functioning. Location: central‐western Argentina, central England, northern upland Iran, north‐eastern Spain. Recurrent patterns ecological specialization: Through ordination a matrix 640 vascular taxa by 12 standardized detected similar specialization four floras. The first PCA axis was an resource capture, usage release. 2 appeared be size‐related axis. Individual each country showed that same remained valuable capture utilization all them, despite major differences climate, biogeography land‐use. results were not significantly driven taxa: main determining 1 very eudicotyledons monocotyledons Asteraceae, Fabaceae Poaceae. Links between recurrent suites ‘soft’ ‘hard’ traits: validity key predictor tested comparisons this values more rigorously established (‘hard’ traits) floras Argentina England. correlated relative growth rate, leaf nitrogen content, litter decomposition rate. It also coincided palatability model generalist herbivores. Therefore, location on can linked processes those habitats where plants are dominant. Conclusion: We confirm at global scale evolutionary specialization, previously recognised several local This reflects fundamental trade‐off rapid acquisition resources conservation within well‐protected tissues. These trends maintained across different environmental situations (including proximate causes low productivity, i.e. drought or mineral nutrient deficiency). consistent phylogenetic groups, directly relevant processes.

Language: Английский

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PLANT RESPONSES TO INSECT HERBIVORY: The Emerging Molecular Analysis

Annual Review of Plant Biology, Journal Year: 2002, Volume and Issue: 53(1), P. 299 - 328

Published: June 1, 2002

▪ Abstract Plants respond to herbivore attack with a bewildering array of responses, broadly categorized as direct and indirect defenses, tolerance. Plant-herbivore interactions are played out on spatial scales that include the cellular well-studied in plant-pathogen interactions, well responses function at whole-plant community levels. The plant's wound response plays central role but is frequently altered by insect-specific elicitors, giving plants potential optimize their defenses. In this review, we emphasize studies advance molecular understanding elicited defenses verifications insect bioassays. Large-scale transcriptional changes accompany insect-induced resistance, which organized into specific temporal patterns points existence herbivore-specific trans-activating elements orchestrating responses. Such organizational could help elucidate control over diversity attack.

Language: Английский

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Novel weapons: invasive success and the evolution of increased competitive ability

Frontiers in Ecology and the Environment, Journal Year: 2004, Volume and Issue: 2(8), P. 436 - 443

Published: Oct. 1, 2004

When introduced to new habitats by humans, some plant species become much more dominant. This is primarily attributed escape from specialist consumers. Release these enemies also thought lead the evolution of increased competitive ability, driven a decrease in plant's resource allocation consumer defense and an increase size or fecundity. Here, we discuss theory for invasive success – “novel weapons hypothesis”. We propose that invaders transform because they possess novel biochemical function as unusually powerful allelopathic agents, mediators plant–soil microbial interactions. Root exudates are relatively ineffective against their natural neighbors adaptation, may be highly inhibitory newly encountered plants invaded communities. In other words, provide them with advantage arise differences regional coevolutionary trajectories Furthermore, selective possessing weapon result rapid example, production greater quantities antimicrobial root exudates. Direct selection traits provides alternative “grow versus defend” trade-offs underpin ability.

Language: Английский

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Growth–Defense Tradeoffs in Plants: A Balancing Act to Optimize Fitness

Molecular Plant, Journal Year: 2014, Volume and Issue: 7(8), P. 1267 - 1287

Published: April 29, 2014

Language: Английский

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The costs of reproduction in plants

New Phytologist, Journal Year: 2002, Volume and Issue: 155(3), P. 321 - 348

Published: Aug. 20, 2002

Summary This review reports on the processes associated with costs of reproduction, including some theoretical considerations, definitions and methodological aspects, followed by a list situations where are difficult to find. Despite exceptions, case studies, examined trade‐offs between reproduction other life‐history traits, generally support predictions cost hypothesis. The as an evolutionary determinant sexual dimorphism in life history traits dioecious species was specifically tested, considering that higher females has driven related dimorphism. Females woody were consistently smaller than males supporting By contrast, herbaceous perennials larger sex, which did not fit expectations Finally, mechanisms enable compensation reproductive detailed, plastic responses photosynthesis growth, effects timing investment, plant architecture physiological integration. Contents 321 I. Introduction II. Theory 322 III. Methodological aspects 324 IV. Empirical evidence 328 V. Plant size 330 VI. Costs sexually dimorphic plants 331 VII. Compensation 333 VIII. Concluding comments future perspectives 336 Acknowledgements 337 References

Language: Английский

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