College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
Sci Rep. 2023 Aug 2;13(1):12567. doi: 10.1038/s41598-023-39235-x.
Castanopsis fissa is a native, broadleaf tree species in Guangdong with characteristics of barrenness and fast growth and is often used as a pioneer species for vegetation restoration with excellent ecological benefits. To explore the response of C.fissa to drought, this study investigated the drought tolerance mechanism of C.fissa using physiological and proteomic assessments. Using a potted continuous drought experimental method with normal water supply as a control, we measured photosynthetic parameters, antioxidant enzyme activities, and osmoregulatory substances of C. fissa in response to drought stress for 1 to 4 weeks, respectively. In addition, we used TMT quantitative proteomics to identify differentially expressed proteins (DEPs) between the drought-stress-treated C. fissa leaves and the control leaves. With the extension of drought stress time, the photosynthetic indexes and peroxidase (POD) activity of C. fissa leaves showed a decreasing trend. The malondialdehyde (MDA) content; superoxide Dismutase (SOD) and catalase (CAT) activities; and proline (Pro), soluble sugar (SS) and soluble protein (SP) contents showed an overall increasing trend, all of which reached significant differences at 4 w of stress. We identified 177 and 529 DEPs in the 2 and 4 weeks drought-stress leaves, respectively, in reference to the control leaves. These DEPs were closely related to physiological metabolic processes such as photosynthesis, energy and carbohydrate metabolism, stress response and defense, transcriptional regulation, and signal ion transduction. Drought stress mainly affects photosynthesis, carbohydrate metabolism, and protein synthesis and degradation in C. fissa leaves. At 2 weeks of stress, the expression of carbon metabolism, pyruvate metabolism and ribosome-related proteins was significantly changed, however, and at 4 weeks of stress, protein processing in the endoplasmic reticulum and spliceosome-related proteins were significantly increased in plant leaves. To alleviate the effect of water unavailability, the drought-stressed C.fissa leaves increased its oxidative protective enzyme system to eliminate excess reactive oxygen species (ROS) and also increased its Pro and SP contents to maintain the intracellular osmotic potential balance.
锥栗是广东地区特有的一种阔叶树种，具有贫瘠和生长迅速的特点，常被用作植被恢复的先锋物种，具有极好的生态效益。为了探索锥栗对干旱的响应，本研究采用生理和蛋白质组学评估方法研究了锥栗的耐旱机制。使用盆栽连续干旱实验方法，以正常供水作为对照，分别测量了锥栗在干旱胁迫下 1 至 4 周的光合参数、抗氧化酶活性和渗透调节物质。此外，我们使用 TMT 定量蛋白质组学方法鉴定了干旱胁迫处理的锥栗叶片与对照叶片之间的差异表达蛋白 (DEPs)。随着干旱胁迫时间的延长，锥栗叶片的光合指标和过氧化物酶（POD）活性呈下降趋势。丙二醛（MDA）含量；超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性；脯氨酸（Pro）、可溶性糖（SS）和可溶性蛋白（SP）含量呈整体上升趋势，在胁迫 4w 时均达到显著差异。与对照叶片相比，我们在 2 周和 4 周干旱胁迫叶片中分别鉴定出 177 和 529 个 DEPs。这些 DEPs与光合作用、能量和碳水化合物代谢、应激响应和防御、转录调节以及信号离子转导等生理代谢过程密切相关。干旱胁迫主要影响锥栗叶片的光合作用、碳水化合物代谢和蛋白质合成与降解。在胁迫 2 周时，碳代谢、丙酮酸代谢和核糖体相关蛋白的表达发生显著变化，而在胁迫 4 周时，植物叶片内质网蛋白加工和剪接体相关蛋白的表达显著增加。为了缓解水分不足的影响，受胁迫的锥栗叶片增加了其氧化保护酶系统以消除过量的活性氧（ROS），并增加了其 Pro 和 SP 含量以维持细胞内渗透压平衡。
