Divergent leaf and fine root “pressure–volume relationships” across habitats with varying water availability

编号 040037801

推送时间 20230116

研究领域 森林培育 

年份 2022 

类型 期刊 

语种 英语

标题 Divergent leaf and fine root “pressure–volume relationships” across habitats with varying water availability

来源期刊 Plant physiology

期 第378期

发表时间 20220901

关键词 fine roots;  hydraulic vulnerability segmentation;  karst;  leaves;  mangrove;  pressure–volume curve;  turgor loss.; 

摘要 Fine roots and leaves, the direct interfaces of plants with their external environment along the soil–plant–atmosphere continuum, are at the front line to ensure plant adaptation to their growing habitat. This study aimed to compare the vulnerability to water deficit of fine roots and leaves of woody species from karst and mangrove forests—two water-stressed habitats—against that of timber and ornamental woody species grown in a well-watered common garden. Thus, pressure–volume curves in both organs of 37 species (about 12 species from each habitat) were constructed. Fine roots wilted at a less negative water potential than leaves in 32 species and before branch xylem lost 50% of its hydraulic conductivity in the 17 species with available data on branch xylem embolism resistance. Thus, turgor loss in fine roots can act as a hydraulic fuse mechanism against water stress. Mangroves had higher leaf resistance against wilting and lower leaf-specific area than the karst and common garden plants. Their fine roots had high specific root lengths (SRL) and high capacitance to buffer water stress. Karst species had high leaf bulk modulus, low leaf capacitance, and delayed fine root wilting. This study showed the general contribution of fine roots to the protection of the whole plant against underground water stress. Our findings highlight the importance of water storage in the leaves and fine roots of mangrove species and high tolerance to water deficit in the leaves of mangrove species and the fine roots of some karst species.

服务人员 孙小满

服务院士 尹伟伦

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