Effects of Melatonin on Anti-oxidative Systems and Photosystem II in Cold-Stressed Rice Seedlings.
Effects of Melatonin on Anti-oxidative Systems and Photosystem II in Cold-Stressed Rice Seedlings.
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DOI：
10.3389/fpls.2017.00785
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发表时间：
2017
影响因子：
5.6
通讯作者：
Yuan M
中科院分区：
文献类型：
--
作者：
Han QH;Huang B;Ding CB;Zhang ZW;Chen YE;Hu C;Zhou LJ;Huang Y;Liao JQ;Yuan S;Yuan M
褪黑激素（Melatonin，N-acetyl-5-methoxytryptamine）在植物的多种发育过程和逆境应答中起着重要作用。采用0、20和100 μM褪黑激素溶液浸种、浸根和叶面喷施3种方法，研究了褪黑激素在水稻生长、光合作用和冷胁迫反应中的可能调节作用。低温胁迫6 d后，水稻幼苗的生长受到明显抑制，但外源褪黑激素可缓解这种抑制作用。此外，外源褪黑素预处理减轻了低温胁迫引起的活性氧、丙二醛的积累和细胞死亡。褪黑激素预处理也缓解了胁迫诱导的光合作用和光系统II活性抑制。进一步的研究表明，褪黑素预处理提高了抗氧化酶活性和非酶抗氧化水平。浸种和浸根处理比喷雾处理能更有效地提高大豆的抗寒性。结果还表明，褪黑激素对水稻生理生化和光合参数的影响具有剂量依赖性。
Melatonin (N-acetyl-5-methoxytryptamine) plays important role in multiple plant developmental processes and stress responses. We investigated the possible mediatory role of melatonin in growth, photosynthesis, and the response to cold stress in rice by using three different experiments: soaking seed; immersing roots, and spraying to leaves with 0, 20, or 100 μM melatonin. After 6 days of cold stress, the growth of rice seedlings was significantly inhibited, but this inhibition was alleviated by exogenous melatonin. Furthermore, exogenous melatonin pretreatment alleviated the accumulation of reactive oxygen species, malondialdehyde and cell death induced by cold stress. Melatonin pretreatment also relieved the stress-induced inhibitions to photosynthesis and photosystem II activities. Further investigations showed that, antioxidant enzyme activities and non-enzymatic antioxidant levels were increased by melatonin pretreatments. The treatment methods of seed soaking and root immersion were more effective in improving cold stress resistance than the spraying method. The results also indicated the dose-dependent response of melatonin on rice physiological, biochemical, and photosynthetic parameters.