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Combined high leaf hydraulic safety and efficiency provides drought tolerance in Caragana species adapted to low mean annual precipitation
Author(s) -
Yao GuangQian,
Nie ZhengFei,
Turner Neil C.,
Li FengMin,
Gao TianPeng,
Fang XiangWen,
Scoffoni Christine
Publication year - 2021
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.16845
Subject(s) - turgor pressure , xylem , dehydration , biology , drought tolerance , stomatal conductance , abscisic acid , caragana , water use efficiency , botany , agronomy , horticulture , photosynthesis , biochemistry , gene
Summary Clarifying the coordination of leaf hydraulic traits with gas exchange across closely‐related species adapted to varying rainfall can provide insights into plant habitat distribution and drought adaptation. The leaf hydraulic conductance ( K leaf ), stomatal conductance ( g s ), net assimilation ( A ), vein embolism and abscisic acid (ABA) concentration during dehydration were quantified, as well as pressure–volume curve traits and vein anatomy in 10 Caragana species adapted to a range of mean annual precipitation (MAP) conditions and growing in a common garden. We found a positive correlation between Ψ leaf at 50% loss of K leaf ( K leaf P 50 ) and maximum K leaf ( K leaf‐max ) across species. Species from low‐MAP environments exhibited more negative K leaf P 50 and turgor loss point, and higher K leaf‐max and leaf‐specific capacity at full turgor, along with higher vein density and midrib xylem per leaf area, and a higher ratio of K leaf‐max : maximum g s . Tighter stomatal control mediated by higher ABA accumulation during dehydration in these species resulted in an increase in hydraulic safety and intrinsic water use efficiency (WUE i ) during drought. Our results suggest that high hydraulic safety and efficiency combined with greater stomatal sensitivity triggered by ABA production and leading to greater WUE i provides drought tolerance in Caragana species adapted to low‐MAP environments.