Physiological, Photosynthetic and Stomatal Ultrastructural Responses of Quercus acutissima Seedlings to Drought Stress and Rewatering

作者：Dan Liu, Haili Guo, Liping Yan, Lei Gao, Shasha Zhai, Yan Xu · 发表于：Forests · 年份：2023 · DOI：10.3390/f15010071 · 被引用次数：21 · 研究领域：Plant Water Relations and Carbon Dynamics、Plant Stress Responses and Tolerance、Plant responses to water stress

The physiological mechanisms of drought-stress response in Quercus acutissima were explored with the aim to develop potentially valuable drought-resistant species that are adapted to arid regions and barren mountains. Potting experiments of Q. acutissima that simulated drought-stress conditions, and morphological, physiological, photosynthetic, and ultrastructural changes were investigated at different stages of drought stress, including after rehydration and recovery. During drought stress and rewatering, the leaves exhibited yellowing and abscission, followed by the sprouting of new leaf buds. The relative water content (RWC) changed under the drought-rewatering treatment, with a decreasing and then increasing trend, while the relative electrical conductivity (REC) had a more gradual increasing and then decreasing trend. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and the proline (Pro) and soluble sugar (SS) contents increased and then decreased. The change in soluble protein (SP) content showed an N-shaped trend of increasing, decreasing, and then increasing again. The malondialdehyde (MDA) content decreased and then slowly increased. From the drought to recovery phase of the experiment, the net photosynthesis (Pn), stomatal conductance (Gs), and transpiration rate (Tr) decreased gradually at first, and then the Pn increased significantly, while the Gs and Tr increased slowly. During this period, the internal CO2 concentration (Ci) d...