Institute of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences/Jilin Provincial Key Laboratory of Agricultural Biotechnology, Changchun 130033, China.
College of Plant Science, Jilin University, Changchun 130062, China.
Int J Mol Sci. 2019 Nov 26;20(23):5956. doi: 10.3390/ijms20235956.
Drought stress, especially during the seedling stage, seriously limits the growth of maize and reduces production in the northeast of China. To investigate the molecular mechanisms of drought response in maize seedlings, proteome changes were analyzed. Using an isotopic tagging relative quantitation (iTRAQ) based method, a total of 207 differentially accumulated protein species (DAPS) were identified under drought stress in maize seedlings. The DAPS were classified into ten essential groups and analyzed thoroughly, which involved in signaling, osmotic regulation, protein synthesis and turnover, reactive oxygen species (ROS) scavenging, membrane trafficking, transcription related, cell structure and cell cycle, fatty acid metabolism, carbohydrate and energy metabolism, as well as photosynthesis and photorespiration. The enhancements of ROS scavenging, osmotic regulation, protein turnover, membrane trafficking, and photosynthesis may play important roles in improving drought tolerance of maize seedlings. Besides, the inhibitions of some protein synthesis and slowdown of cell division could reduce the growth rate and avoid excessive water loss, which is possible to be the main reasons for enhancing drought avoidance of maize seedlings. The incongruence between protein and transcript levels was expectedly observed in the process of confirming iTRAQ data by quantitative real-time polymerase chain reaction (qRT-PCR) analysis, which further indicated that the multiplex post-transcriptional regulation and post-translational modification occurred in drought-stressed maize seedlings. Finally, a hypothetical strategy was proposed that maize seedlings coped with drought stress by improving drought tolerance (via. promoting osmotic adjustment and antioxidant capacity) and enhancing drought avoidance (via. reducing water loss). Our study provides valuable insight to mechanisms underlying drought response in maize seedlings.
干旱胁迫，特别是在幼苗期，严重限制了中国东北地区玉米的生长和产量。为了研究玉米幼苗对干旱的响应机制，我们分析了蛋白质组的变化。采用同位素标记相对定量(iTRAQ)方法，在玉米幼苗干旱胁迫下共鉴定出 207 种差异积累蛋白(DAPS)。将 DAPS 分为十个必需组进行深入分析，涉及信号转导、渗透调节、蛋白质合成和周转、活性氧(ROS)清除、膜转运、转录相关、细胞结构和细胞周期、脂肪酸代谢、碳水化合物和能量代谢，以及光合作用和光呼吸。增强的 ROS 清除、渗透调节、蛋白质周转、膜转运和光合作用可能在提高玉米幼苗的耐旱性方面发挥重要作用。此外，一些蛋白质合成的抑制和细胞分裂的减缓可能会降低生长速度并避免过度失水，这可能是增强玉米幼苗避旱的主要原因。通过定量实时聚合酶链反应(qRT-PCR)分析对 iTRAQ 数据进行确认的过程中，预期观察到了蛋白质和转录水平之间的不一致性，这进一步表明，在干旱胁迫下的玉米幼苗中发生了多重转录后调控和翻译后修饰。最后，提出了一个假设的策略，即玉米幼苗通过提高耐旱性(通过促进渗透调节和抗氧化能力)和增强避旱性(通过减少水分流失)来应对干旱胁迫。本研究为玉米幼苗对干旱的响应机制提供了有价值的见解。
