Zhang Xiaoxing, Meng Wenjing, Liu Dapu, Pan Dezhuo, Yang Yanzhao, Chen Zhuo, Ma Xiaoding, Yin Wenchao, Niu Mei, Dong Nana, Liu Jihong, Shen Weifeng, Liu Yuqin, Lu Zefu, Chu Chengcai, Qian Qian, Zhao Mingfu, Tong Hongning
State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Rice Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350018, China.
Science. 2024 Mar 8;383(6687):eadk8838. doi: 10.1126/science.adk8838.
Crop yield potential is constrained by the inherent trade-offs among traits such as between grain size and number. Brassinosteroids (BRs) promote grain size, yet their role in regulating grain number is unclear. By deciphering the clustered-spikelet rice germplasm, we show that activation of the BR catabolic gene () markedly increases grain number. We establish a molecular pathway in which the BR signaling inhibitor GSK3/SHAGGY-LIKE KINASE2 phosphorylates and stabilizes OsMADS1 transcriptional factor, which targets -like gene . The tissue-specific activation of in the secondary branch meristems enhances panicle branching, minimizing negative effects on grain size, and improves grain yield. Our study showcases the power of tissue-specific hormonal manipulation in dismantling the trade-offs among various traits and thus unleashing crop yield potential in rice.
作物产量潜力受到诸如粒大小与粒数等性状之间内在权衡的限制。油菜素类固醇（BRs）促进粒大小，但其在调节粒数方面的作用尚不清楚。通过对簇生小穗水稻种质的解析，我们发现BR分解代谢基因（）的激活显著增加了粒数。我们建立了一条分子途径，其中BR信号抑制剂GSK3/SHAGGY样激酶2磷酸化并稳定OsMADS1转录因子，该转录因子靶向类基因。在二次分支分生组织中对的组织特异性激活增强了穗分支，将对粒大小的负面影响降至最低，并提高了谷物产量。我们的研究展示了组织特异性激素调控在消除各种性状之间的权衡从而释放水稻作物产量潜力方面的作用。
