文章基本信息

标题：The correlations and sequence of plant stomatal, hydraulic, and wilting responses to drought
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作者：Megan K. Bartlett ; Tamir Klein ; Steven Jansen 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：46
页码：13098-13103
DOI：10.1073/pnas.1604088113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceMany plant species face increasing drought under climate change, making plant drought tolerance integral to predicting species and ecosystem responses. Many physiology traits interact to determine overall drought tolerance, but trait relationships have not been assessed for general patterns across global plant diversity. We analyzed stomatal, hydraulic, and mesophyll drought tolerance traits for 310 species from ecosystems worldwide. We evaluated the sequence of drought responses for plants under increasing water stress, and showed that coselection with environmental water stress drives most trait correlations across species, with functional coordination additionally important for some relationships. These results provide insight into how variation in multiple traits should be represented within plants and across species in models of plant responses to drought. Climate change is expected to exacerbate drought for many plants, making drought tolerance a key driver of species and ecosystem responses. Plant drought tolerance is determined by multiple traits, but the relationships among traits, either within individual plants or across species, have not been evaluated for general patterns across plant diversity. We synthesized the published data for stomatal closure, wilting, declines in hydraulic conductivity in the leaves, stems, and roots, and plant mortality for 262 woody angiosperm and 48 gymnosperm species. We evaluated the correlations among the drought tolerance traits across species, and the general sequence of water potential thresholds for these traits within individual plants. The trait correlations across species provide a framework for predicting plant responses to a wide range of water stress from one or two sampled traits, increasing the ability to rapidly characterize drought tolerance across diverse species. Analyzing these correlations also identified correlations among the leaf and stem hydraulic traits and the wilting point, or turgor loss point, beyond those expected from shared ancestry or independent associations with water stress alone. Further, on average, the angiosperm species generally exhibited a sequence of drought tolerance traits that is expected to limit severe tissue damage during drought, such as wilting and substantial stem embolism. This synthesis of the relationships among the drought tolerance traits provides crucial, empirically supported insight into representing variation in multiple traits in models of plant and ecosystem responses to drought.
关键词：drought tolerance ; stem hydraulics ; leaf hydraulics ; stomatal closure ; turgor loss point