Collaborative Innovation Center of Henan Grain Crops/State Key Laboratory of Wheat and Maize Crop Science/College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
Collaborative Innovation Center of Henan Grain Crops/State Key Laboratory of Wheat and Maize Crop Science/College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.
Plant Physiol Biochem. 2019 Sep;142:263-274. doi: 10.1016/j.plaphy.2019.07.012. Epub 2019 Jul 10.
To explain the underlying mechanism of melatonin-mediated drought stress responses in maize, maize pre-treated with or without melatonin was subjected to 20% PEG nutrient solution to induce drought stress. We found that exogenous melatonin significantly improved drought tolerance, demonstrated by improved photosynthesis, reduced ROS accumulation, enhanced activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and increased content of glutathione (GSH). Comparative iTRAQ proteomic analyses revealed a higher abundance of differentially expressed proteins (DEPs) in melatonin-treated maize under drought stress for carbon fixation in photosynthetic organisms, photosynthesis, biosynthesis of amino acids, and biosynthesis of secondary metabolites, compared to untreated plants. Changes in the above molecular mechanisms could explain the melatonin-induced physiological effects associated with drought tolerance. In summary, this study provides a more integrated picture about the effects of melatonin on the physiological and molecular mechanisms in maize seedlings responding to drought stress.
为了解释褪黑素介导的玉米干旱胁迫响应的潜在机制，用或不用褪黑素预处理的玉米用 20%PEG 营养液处理以诱导干旱胁迫。我们发现，外源褪黑素显著提高了玉米的耐旱性，表现为光合作用改善、ROS 积累减少、超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性增强，以及谷胱甘肽（GSH）含量增加。比较 iTRAQ 蛋白质组学分析显示，在干旱胁迫下，与未处理的植株相比，褪黑素处理的玉米中与光合作用生物中的碳固定、光合作用、氨基酸生物合成和次生代谢物生物合成相关的差异表达蛋白（DEPs）的丰度更高。上述分子机制的变化可以解释褪黑素诱导的与耐旱性相关的生理效应。总之，本研究提供了一个更全面的关于褪黑素对玉米幼苗响应干旱胁迫的生理和分子机制的影响的图景。
