Wang Yueying, Lv Yang, Wen Yi, Wang Junge, Hu Peng, Wu Kaixiong, Chai Bingze, Gan Shuxian, Liu Jialong, Wu Yue, Zhu Lixin, Dong Nannan, Tan Yiqing, Wu Hao, Zhang Guangheng, Zhu Li, Ren Deyong, Zhang Qiang, Wang Yuexing, Qian Qian, Hu Jiang
State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou, 311401, China.
Institute of Agricultural Sciences, Xishuangbanna Prefecture, Jinghong, Yunnan Province, 666100, China.
New Phytol. 2025 Mar;245(6):2726-2743. doi: 10.1111/nph.20412. Epub 2025 Jan 31.
Panicle size and grain number are important agronomic traits that determine grain yield in rice. However, the underlying mechanism regulating panicle size and grain number remains largely unknown. Here, we report that GS2 plays an important role in regulating panicle architecture. The RNAi of GS2™ (target site mutation, TM) produced erect and dense panicle with increased primary and secondary branches and grain number per panicle, whereas the overexpression of GS2™ showed longer panicles and fewer grains than wild-type. GS2 directly binds to the GCCA motif and significantly enhances the transcriptional activation ability through the interaction with IPA1. DEP1 is a common target gene of GS2 and IPA1 in regulating branch number and grain number per panicle. The pyramiding of GS2™ and IPA1™ (Target site mutation1, TM1) on hybrid rice can significantly increase rice yield. Our findings reveal the novel function of GS2 and the molecular mechanism of GS2/IPA1-DEP1 module in controlling panicle architecture.
穗大小和粒数是决定水稻产量的重要农艺性状。然而，调控穗大小和粒数的潜在机制仍 largely 未知。在此，我们报道 GS2 在调控穗结构中起重要作用。GS2™（靶位点突变，TM）的 RNAi 产生直立且密集的穗，其一级和二级分支以及每穗粒数增加，而 GS2™ 的过表达显示穗比野生型更长但粒数更少。GS2 直接结合 GCCA 基序，并通过与 IPA1 相互作用显著增强转录激活能力。DEP1 是 GS2 和 IPA1 在调控每穗分支数和粒数方面的共同靶基因。在杂交水稻上聚合 GS2™ 和 IPA1™（靶位点突变 1，TM1）可显著提高水稻产量。我们的研究结果揭示了 GS2 的新功能以及 GS2/IPA1 - DEP1 模块在控制穗结构中的分子机制。
