Drought acclimation of Quercus ilex leaves improves tolerance to moderate drought but not resistance to severe water stress

编号 040034901

推送时间 20220627

研究领域 森林培育 

年份 2022 

类型 期刊 

语种 英语

标题 Drought acclimation of Quercus ilex leaves improves tolerance to moderate drought but not resistance to severe water stress

来源期刊 Plant,Cell & Environment

期 第349期

发表时间 20220408

关键词 water use efficiency;  plant functional types;  climates;  grassland;  permanent wetland;  savannah;  deciduous
broadleaf and deciduous needleleaf forest; 

摘要 Increasing temperature and drought can result in leaf dehydration and defoliation even in drought-adapted tree species such as the Mediterranean evergreen Quercus ilex L. The stomatal regulation of leaf water potential plays a central role in avoiding this phenomenon and is constrained by a suite of leaf traits including hydraulic conductance and vulnerability, hydraulic capacitance, minimum conductance to water vapor, osmotic potential and cell wall elasticity. We investigated whether the plasticity in these traits may improve leaf tolerance to drought in two long-term rainfall exclusion experiments in Mediterranean forests. Osmotic adjustment was observed to lower the water potential at turgor loss in the rainfall-exclusion treatments, thus suggesting a stomatal closure at more negative water potentials and a more anisohydric behavior in drier conditions. Conversely, leaf hydraulic conductance and vulnerability did not exhibit any plasticity between treatments so the hydraulic safety margins were narrower in the rainfall-exclusion treatments. The sequence of leaf responses to seasonal drought and dehydration was conserved among treatments and sites but trees were more likely to suffer losses of turgor and hydraulic functioning in the rainfall-exclusion treatments. We conclude that leaf plasticity might help the trees to tolerate moderate drought but not to resist severe water stress.

服务人员 孙小满

服务院士 尹伟伦

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