Brassinosteroids facilitate controlled soil drying to mitigate heat stress on pistil fertilization in photo-thermosensitive genetic male-sterile rice

作者：Weiyang Zhang, Wei Cai, Yujiao Zhou, Ying Liu, Wenqian Miao, Kuanyu Zhu, Weilu Wang, Yunji Xu, Yidi Sun, Junfei Gu, Hao Zhang, Zhiqin Wang, Lijun Liu, Jianhua Zhang, Jianchang Yang · 发表于：Journal of Integrative Agriculture · 年份：2025 · DOI：10.1016/j.jia.2025.04.036 · 被引用次数：1 · 研究领域：Rice Cultivation and Yield Improvement、Plant responses to water stress、Plant Stress Responses and Tolerance

• Moderate soil drying mitigates heat stress on pistil fertilization in PTGMS rice better than conventional well-watered method. • Moderate soil drying maintains water and redox homeostasis in PTGMS rice plants under heat stress. • Brassinosteroids mediate the effectiveness of moderate soil drying in alleviating heat stress on PTGMS rice. Globally recurrent extreme high temperature (HT) events severely limit rice production. This study investigated whether a controlled moderate soil drying (MD) could replace the conventional well-watered (WW) regime to more effectively mitigate HT stress on pistil fertilization in photo-thermosensitive genetic male-sterile (PTGMS) rice, and examined the role of brassinosteroids (BRs). Two PTGMS rice varieties were cultivated under normal temperature (NT) and HT conditions, paired WW and MD strategies during anthesis. In conventional WW regime, waterlogging reduces BRs levels in roots and pistils due to excessive decomposition, weakening active water uptake driven by root activity and failing to alleviate transpiration-pulled passive water extraction hampered by restricted stomatal openings. Thereby, it causes water imbalance in plants and weakened pistil function due to a suppressed ascorbate-glutathione (AsA-GSH) cycle and hyperactive nicotinamide adenine dinucleotide phosphate oxidase (NOX) activity. This exacerbates pistil fertilization impairment and hybrid seed yield loss under HT stress. Conversely, by promoting BR synthesis and inhibit...