Research progress in rice seed dormancy and germination regulated by plant hormones
Xu Shi, Junting Jia, Songquan Song, Zhangyan Dai, Yongjian Luo, Yuejiao Wang, Chengwei Yang, Jun Liu
Abstract
Rice (<italic>Oryza sativa</italic> L.) is a globally significant agricultural commodity that is crucial for maintaining stable food supplies worldwide. The speed and uniformity of seed germination are fundamental prerequisites for achieving optimal rice productivity and grain excellence. Seed germination is a result of complex interactions between hereditary traits and external conditions. Hormonal control governs the termination of dormancy termination and the initiation of sprouting initiation, a process that is evolutionarily preserved across seed-bearing flora. Abscisic acid (ABA) functions as a stimulant for dormancy initiation and preservation, and simultaneously inhibits the germination process. Conversely, gibberellins (GAs) actively facilitate seedling emergence following dormancy cessation. Ethylene regulates the germination and dormancy of many species via complex signaling networks. The auxin signaling cascade contributes to seed sprouting by regulating the ABA and GA signaling networks. Germination exhibits dose-dependent responsiveness to auxin levels, and cytokinins actively stimulate seed sprouting. In addition to these primary regulators, secondary plant growth substances, including brassinosteroids, strigolactones, jasmonates, and salicylates, significantly contribute to germination modulation mechanisms. This comprehensive analysis focuses on contemporary scientific advancements in understanding the molecular mechanisms of phytohormonal regulation of dormancy and germination processes in rice. Finally, we outline the scientific issues that require further research in this field and provide references for future studies on the molecular mechanisms by which plant hormones regulate rice seed dormancy and germination, as well as the development of new rice varieties.