College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
BMC Plant Biol. 2021 Nov 4;21(1):513. doi: 10.1186/s12870-021-03295-w.
Drought stress severely limits maize seedling growth and crop yield. Previous studies have elucidated the mechanisms by which maize acquires drought resistance and contends with water deficiency. However, the link between the physiological and molecular variations among maize cultivars are unknown. Here, physiological and proteomic analyses were conducted to compare the stress responses of two maize cultivars with contrasting drought stress tolerance.
The physiological analysis showed that the drought-tolerant SD609 maize variety maintains relatively high photochemical efficiency by enhancing its protective cyclic electron flow (CEF) mechanism and antioxidative enzymes activities. Proteomics analysis revealed that 198 and 102 proteins were differentially expressed in SD609 and the drought-sensitive SD902 cultivar, respectively. GO and KEGG enrichments indicated that SD609 upregulated proteins associated with photosynthesis, antioxidants/detoxifying enzymes, molecular chaperones and metabolic enzymes. Upregulation of the proteins related to PSII repair and photoprotection improved photochemical capacity in SD609 subjected to moderate drought stress. In SD902, however, only the molecular chaperones and sucrose synthesis pathways were induced and they failed to protect the impaired photosystem. Further analysis demonstrated that proteins related to the electron transport chain (ETC) and redox homeostasis as well as heat shock proteins (HSPs) may be important in protecting plants from drought stress.
Our experiments explored the mechanism of drought tolerance and clarified the interconnections between the physiological and proteomic factors contributing to it. In summary, our findings aid in further understanding of the drought tolerance mechanisms in maize.
干旱胁迫严重限制了玉米幼苗的生长和作物产量。先前的研究已经阐明了玉米获得抗旱性和应对水分不足的机制。然而，不同玉米品种之间生理和分子变化之间的联系尚不清楚。在这里，进行了生理和蛋白质组学分析，以比较两种具有不同耐旱性的玉米品种的应激反应。
生理分析表明，耐旱性 SD609 玉米品种通过增强其保护性循环电子流（CEF）机制和抗氧化酶活性，保持相对较高的光化学效率。蛋白质组学分析显示，SD609 和耐旱性差的 SD902 品种分别有 198 和 102 种蛋白质差异表达。GO 和 KEGG 富集表明，SD609 上调了与光合作用、抗氧化剂/解毒酶、分子伴侣和代谢酶相关的蛋白质。在中度干旱胁迫下，与 PSII 修复和光保护相关的蛋白质的上调提高了 SD609 的光化学能力。然而，在 SD902 中，只有分子伴侣和蔗糖合成途径被诱导，它们无法保护受损的光系统。进一步分析表明，与电子传递链（ETC）和氧化还原稳态以及热休克蛋白（HSPs）相关的蛋白质可能在保护植物免受干旱胁迫方面很重要。
我们的实验探索了耐旱性的机制，并阐明了导致耐旱性的生理和蛋白质组学因素之间的联系。总之，我们的研究结果有助于进一步了解玉米的耐旱性机制。
