文献类型： 外文期刊

作者： Jiang, Dan ¹ ; Lu, Bin ³ ; Liu, Liantao ² ; Duan, Wenjing ¹ ; Chen, Li ¹ ; Li, Jin ¹ ; Zhang, Ke ² ; Sun, Hongchun ² ; Zhang, Yongjiang ² ; Dong, Hezhong ² ; Li, Cundong ² ; Bai, Zhiying ¹ ;

作者机构： 1.Hebei Agr Univ, State Key Lab North China Crop Improvement & Regu, Coll Life Sci, Baoding, Peoples R China

2.Hebei Agr Univ, State Key Lab North China Crop Improvement & Regu, Key Lab Crop Growth Regulat Hebei Prov, Coll Agron, Baoding, Peoples R China

3.Hebei Agr Univ, Coll Landscape & Tourism, Baoding, Peoples R China

4.Shandong Acad Agr Sci, Cotton Res Ctr, Minist Agr, Key Lab Cotton Breeding & Cultivat Huang Huai Hai, Jinan, Peoples R China

关键词： Cotton; Melatonin; Salt stress; ROS; Antioxidant systems; Osmotic substance

期刊名称：PEERJ （ 影响因子：2.984； 五年影响因子：3.369 ）

ISSN： 2167-8359

年卷期： 2020 年 8 卷

页码：

收录情况： SCI

摘要： Melatonin is a small-molecule indole hormone that plays an important role in participating in biotic and abiotic stress resistance. Melatonin has been confirmed to promote the normal development of plants under adversity stress by mediating physiological regulation mechanisms. However, the mechanisms by which exogenous melatonin mediates salt tolerance via regulation of antioxidant activity and osmosis in cotton seedlings remain largely unknown. In this study, the regulatory effects of melatonin on reactive oxygen species (ROS), the antioxidant system, and osmotic modulators of cotton seedlings were determined under 0-500 mu M melatonin treatments with salt stress induced by 150 mM NaCl treatment. Cotton seedlings under salt stress exhibited an inhibition of growth, excessive hydrogen peroxide (H2O2), superoxide anion (O-2(-)), and malondialdehyde (MDA) accumulations in leaves, increased activity levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and elevated ascorbic acid (AsA) and glutathione (GSH) content in leaves. However, the content of osmotic regulators (i.e., soluble sugars and proteins) in leaves was reduced under salt stress. This indicates high levels of ROS were produced, and the cell membrane was damaged. Additionally, osmotic regulatory substance content was reduced, resulting in osmotic stress, which seriously affected cotton seedling growth under salt stress. However, exogenous melatonin at different concentrations reduced the contents of H2O2, O-2(-), and MDA in cotton leaves, increased the activity of antioxidant enzymes and the content of reductive substances (i.e., AsA and GSH), and promoted the accumulation of osmotic regulatory substances in leaves under salt stress. These results suggest that melatonin can inhibit ROS production in cotton seedlings, improve the activity of the antioxidant enzyme system, raise the content of osmotic regulation substances, reduce the level of membrane lipid peroxidation, and protect the integrity of the lipid membrane under salt stress, which reduces damage caused by salt stress to seedlings and effectively enhances inhibition of salt stress on cotton seedling growth. These results indicate that 200 mu M melatonin treatment has the best effect on the growth and salt tolerance of cotton seedlings.