The determinants of leaf turgor loss point and prediction of drought tolerance of species and biomes: a global meta-analysis
The determinants of leaf turgor loss point and prediction of drought tolerance of species and biomes: a global meta-analysis
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DOI：
10.1111/j.1461-0248.2012.01751.x
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发表时间：
2012-05-01
期刊：
影响因子：
8.8
通讯作者：
Sack, Lawren
中科院分区：
文献类型：
--
作者：
Bartlett, Megan K.;Scoffoni, Christine;Sack, Lawren
日益严重的干旱是全世界物种和生态系统面临的最严重挑战之一，需要改进理论和实践来量化物种耐受性。膨压损失时的叶片水势(Ptlp)被经典地认为是植物水分胁迫反应的主要生理决定因素。然而，PTLP的细胞学基础及其在预测生态抗旱性方面的重要性一直存在争议。对72个研究中的317个物种进行的荟萃分析表明，ptlp与生物群落内部和跨生物群落的水可获得性密切相关，这表明预测干旱反应的能力。我们推导出了新的方程，给出了膨胀率和失水点的相对含水率(RWCtlp)作为充分膨胀时渗透势(Po)和体积弹性模量值(E)的显式函数。敏感度分析和Meta分析表明，Po是ptlp的主要驱动因素。相反，e在推动物种内或物种间的抗旱性方面没有直接作用，但硬化性和弹性调节作用于维持RWCtlp，防止细胞脱水，并额外保护独立于抗旱性的营养、机械和草食胁迫。这些发现阐明了生物地理趋势和耐旱性参数的基本基础，并将其应用于全世界物种和生态系统的比较评估。
Increasing drought is one of the most critical challenges facing species and ecosystems worldwide, and improved theory and practices are needed for quantification of species tolerances. Leaf water potential at turgor loss, or wilting (ptlp), is classically recognised as a major physiological determinant of plant water stress response. However, the cellular basis of ptlp and its importance for predicting ecological drought tolerance have been controversial. A meta-analysis of 317 species from 72 studies showed that ptlp was strongly correlated with water availability within and across biomes, indicating power for anticipating drought responses. We derived new equations giving both ptlp and relative water content at turgor loss point (RWCtlp) as explicit functions of osmotic potential at full turgor (po) and bulk modulus of elasticity (e). Sensitivity analyses and meta-analyses showed that po is the major driver of ptlp. In contrast, e plays no direct role in driving drought tolerance within or across species, but sclerophylly and elastic adjustments act to maintain RWCtlp, preventing cell dehydration, and additionally protect against nutrient, mechanical and herbivory stresses independent of drought tolerance. These findings clarify biogeographic trends and the underlying basis of drought tolerance parameters with applications in comparative assessments of species and ecosystems worldwide.