Effects of drought hardening on the carbohydrate dynamics of Quercus acutissima seedlings under successional drought

作者：Qiang Li, Xiao Liu, Xinke Sun, Mingming Zhao, Lele Liu, Ning Wang, Qun Gao, Peixian Fan, Ning Du, Hui Wang, Renqing Wang · 发表于：Frontiers in Plant Science · 年份：2023 · DOI：10.3389/fpls.2023.1184584 · 被引用次数：10 · 研究领域：Plant Water Relations and Carbon Dynamics、Seedling growth and survival studies、Plant Stress Responses and Tolerance

Introduction As precipitation patterns are predicted to become increasingly erratic, the functional maintenance of warm-temperate forests constitutes a key challenge for forest managers. In this study, 2-year-old Quercus acutissima seedlings were selected to elucidate the mechanisms whereby they respond to soil water fluctuations and the drought hardening effects on plant carbohydrate dynamics. Methods Seedlings were trained under different soil water conditions for 2 months: drought (D), well-watered (W), 1-month drought and then 1-month well-watered (D-W), and 1-month well-watered and then 1-month drought (W-D). The functional traits involved in water- and carbon-use strategies were explored at the end of the hardening period. Compared with seedlings in group W, seedlings in groups D, D-W, and W-D had increased potential for carbon uptake (i.e., light saturated point, maximum ribulose-1,5-bisphosphate (RuBP) saturated rate, and electron transport rate) and water uptake (i.e., fine root–to–coarse root ratio) and downregulated growth and mitochondrial respiration to decrease carbon consumption. After water fluctuation hardening, we performed a successional dry-down experiment for 1 month to detect carbohydrate dynamics and explore the acclimation caused by prior hardening. Results and discussion Our results revealed that there were more soluble sugars allocated in the leaves and more starch allocated in the stems and roots of seedlings hardened in the D, W-D, and D-W treatmen...