Wang Jing, Fu Bing-Zhe, Li Shu-Xia, Wang Xing, Song Wen-Xue, Ye Yu-Nong, Hu Peng-Fei, Wang Tong-Rui
College of Forestry and Pratacuture, Ningxia University, Yinchuan 750021, China.
Ningxia Grassland and Animal Husbandry Engineering Technology Research Center, Yinchuan 750021, China.
Ying Yong Sheng Tai Xue Bao. 2023 Nov;34(11):2947-2957. doi: 10.13287/j.1001-9332.202311.004.
To clarify the alleviation effect of exogenous melatonin (MT) on under drought stress, we examined the response of 'Yanchi' seedlings to simulated drought stress with polyethylene glycol 6000 (PEG-6000), by investigating the effects of exogenous addition of different concentrations (0, 1, 10, 50, 100, 150 and 200 mg·L) of MT on seedlings growth and physiological characteristics under drought stress. The results showed that drought stress significantly inhibited the growth of seedlings, and that exogenous addition of different concentrations of MT could alleviate the growth inhibition caused by drought stress, with the strongest mitigation effect observed at MT concentration of 100 mg·L. Compared with the drought stress treatment alone, exogenous addition of 100 mg·L MT under drought stress increased plant height, aboveground dry weight, and leaf relative water content by 58.2%, 121.2% and 48.1%. The contents of chlorophyll a, chlorophyll b, carotenoids increased by 48.7%, 80.8% and 38.3%, superoxide dismutase, peroxidase and root activity increased by 12.6%, 33.9% and 39.1%, and the contents of ascorbic acid and glutathione increased by 19.5% and 18.3%, respectively. The contents of proline, soluble sugar and soluble protein were increased by 16.2%, 32.6% and 14.3%, while that of malondialdehyde, hydrogen peroxide and superoxide anion radical were decreased by 45.8%, 65.8% and 30.8%, respectively. In summary, exogenous addition of 100 mg·L MT could improve drought tolerance of seedlings by promoting growth, enhancing antioxidant capacity, increasing the content of osmoregulation substances, inhibiting the excessive production of reactive oxygen, and reducing membrane peroxide level.
为阐明外源褪黑素（MT）对干旱胁迫下[植物名称未给出]的缓解作用，我们通过研究外源添加不同浓度（0、1、10、50、100、150和200 mg·L）的MT对干旱胁迫下[植物名称未给出]幼苗生长和生理特性的影响，来检测‘盐池’幼苗对聚乙二醇6000（PEG - 6000）模拟干旱胁迫的响应。结果表明，干旱胁迫显著抑制了[植物名称未给出]幼苗的生长，外源添加不同浓度的MT可缓解干旱胁迫引起的生长抑制，在MT浓度为100 mg·L时缓解效果最强。与单独干旱胁迫处理相比，干旱胁迫下外源添加100 mg·L MT使株高、地上部干重和叶片相对含水量分别增加了58.2%、121.2%和48.1%。叶绿素a、叶绿素b、类胡萝卜素含量分别增加了48.7%、80.8%和38.3%，超氧化物歧化酶、过氧化物酶和根系活力分别增加了12.6%、33.9%和39.1%，抗坏血酸和谷胱甘肽含量分别增加了19.5%和18.3%。脯氨酸、可溶性糖和可溶性蛋白含量分别增加了16.2%、32.6%和14.3%，而丙二醛、过氧化氢和超氧阴离子自由基含量分别降低了45.8%、65.8%和30.8%。综上所述，外源添加100 mg·L MT可通过促进生长、增强抗氧化能力、增加渗透调节物质含量、抑制活性氧过量产生以及降低膜脂过氧化水平来提高[植物名称未给出]幼苗的耐旱性。
