A molecular framework for the GS2-SUG1 module-mediated control of grain size and weight in rice by Yingjie Li & Ke Huang & Limin Zhang & Baolan Zhang & Penggen Duan & Guozheng Zhang & Xiahe Huang & Chen Zhou & Nannan Han & Leiying Zheng & Yingchun Wang & Yunhai Li instant download

A molecular framework for the GS2-SUG1 module-mediated control of grain size and weight in rice by Yingjie Li & Ke Huang & Limin Zhang & Baolan Zhang & Penggen Duan & Guozheng Zhang & Xiahe Huang & Chen Zhou & Nannan Han & Leiying Zheng & Yingchun Wang & Yunhai Li instant download

Grain size is a key agronomic traits that influence grain yield in crops. Thetranscription factor GS2/OsGRF4 can improve grain size and yield, but itsunderlying mechanism remains unclear. Here we report a suppressor of thegain-of-function alleleGS2AA (SUG1) that encodes a plant-specific protein DEP2/SRS1/EP2/OsRELA and acts as a transcriptional regulator. The sug1 mutantsform short grains, while overexpression of SUG1 results in long grains. GS2directly activates the expression of SUG1. SUG1 associates with transcriptionfactors OsBZR1, OsMADS56 and OsSPL13 to control grain size through GA andBR signaling as well as growth pathways. Natural variation in SUG1 contributesto grain size diversity, and the SUG1Hap2 allele from indica varieties can be usedto improve grain size and yield of japonica varieties with the SUG1Hap3 allele.Thus, our findings uncover that the GS2-SUG1 module controls grain size byintegrating multiple growth signals, providing the potential targets for cropimprovement.