Rapid drought‐recovery of gas exchange in Caragana species adapted to low mean annual precipitation

Abstract

While variation in mean annual precipitation (MAP) of the native habitat of a species has been shown to determine the ability of a species to resist a hydraulic decrease during drought, it remains unknown whether these variations in MAP also influence the ability of a species to recover and survive drought. Leaf hydraulic and gas exchange recovery following drought and the underlying mechanisms of these responses in six Caragana species from habitats along a large precipitation gradient were investigated during rehydration in a common garden. The gas exchange of species from arid habitats recovered more rapidly during rehydration after mild, moderate and severe drought stress treatments than species from humid habitats. The recovery of gas exchange was not associated with foliar abscisic acid concentration, but tightly related to the recovery of leaf hydraulic conductance (Kleaf). The recovery of Kleaf was associated with the loss of Kleaf during dehydration under mild and moderate drought stress, and to leaf xylem embolism formation under severe drought stress. Results pointed to the different ability to recover in gas exchange in six Caragana species post‐drought is associated with the MAP of the species in its native habitat.

The Potential Role of Genic-SSRs in Driving Ecological Adaptation Diversity in Caragana Plants

“…It has been observed that Caragana plants exhibit distinctive distribution patterns, reflecting the evolution of species-specific characteristics in morphology, physiology, and biochemistry [18]. This makes them good candidates for conducting research on plant adaptability [17,[19][20][21]. For instance, C. versicolor is distributed in southern Sichuan, Xizang, and Qinghai, while C. polourensis is observed on the northern slope of Kunlun Mountain in Xinjiang and the northern slope of Qilian Mountain in Gansu.…”

“…C. brachypoda predominantly scatters across piedmont plains, low slopes, and stabilized sandy lands in the semi-desert regions of Inner Mongolia [22]. So far, extensive research has delved into understanding the adaptive strategies of Caragana plants, spanning various domains, including morphological anatomy [19][20][21], geographical distribution [22,23], physiological ecology [22,[24][25][26][27], photosynthetic characteristics [22,[24][25][26][27], phylogenetic analysis [26,27], and population genetics [28][29][30][31][32]. With the advent of advanced gene sequencing technologies, new frontiers have been opened in unraveling the molecular mechanisms governing stress resistance and adaptive evolution within the genus.…”