Melatonin improves the germination rate of cotton seeds under drought stress by opening pores in the seed coat

PeerJ

article

Yandan Bai¹  Shuang Xiao¹  Zichen Zhang¹  Yongjiang Zhang¹  Hongchun Sun¹  Ke Zhang¹  Xiaodan Wang²  Zhiying Bai³  Cundong Li¹  Liantao Liu¹ 

[1] College of Agronomy, HeBei Agricultural University/ State Key Laboratory of North China Crop Improvement and Regulation/ Key Laboratory of Crop Growth Regulation of Hebei Province, Baoding, Hebei Province;College of Traditional Chinese Veterinary Medicine, Hebei Agricultrual University;College of Life Science, Hebei Agricultrual University

关键词: Cotton;    Melatonin;    Seed germination;    Drought stress;    Testa;    Physiology;   

DOI  :  10.7717/peerj.9450

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The germination of cotton (Gossypium hirsutum L.) seeds is affected by drought stress; however, little is known about the physiological mechanism affecting germination and the effect of melatonin (MT) on cotton seed germination under drought stress. Therefore, we studied the effects of exogenous MT on the antioxidant capacity and epidermal microstructure of cotton under drought stress. The results demonstrated a retarded water absorption capacity of testa under drought stress, significantly inhibiting germination and growth in cotton seeds. Drought stress led to the accumulation of reactive oxygen species (ROS), malondialdehyde (MDA), and osmoregulatory substances (e.g., proline, soluble protein, and soluble sugars); it also decreased the activity of antioxidant enzymes and α-amylase. Drought stress inhibited gibberellin acid (GA3) synthesis and increased abscisic acid (ABA) content, seriously affecting seed germination. However, seeds pre-soaked with MT (100 µM) showed a positive regulation in the number and opening of stomata in cotton testa. The exogenous application of MT increased the germination rate, germination potential, radical length, and fresh weight, as well as the activities of superoxide dismutase (SOD), peroxidase (POD), and α-amylase. In addition, MT application increased the contents of organic osmotic substances by decreasing the hydrogen peroxide (H2O2), superoxide anion (O2-), and MDA levels under drought stress. Further analysis demonstrated that seeds pre-soaked with MT alleviated drought stress by affecting the ABA and GA3 contents. Our findings show that MT plays a positive role in protecting cotton seeds from drought stress.

【 授权许可】

CC BY