Wide Grain 3, a GRAS Protein, Interacts with DLT to Regulate Grain Size and Brassinosteroid Signaling in Rice

Weilan Chen; Xiaoling Hu; Li Hu; Xinyue Hou; Zhengyan Xu; Fanmin Yang; Min Yuan; Feifan Chen; Yunxiao Wang; Bin Tu; Ting Li; Liangzhu Kang; Shiwen Tang; Bingtian Ma; Yuping Wang; Shigui Li; Peng Qin; Hua Yuan

doi:10.1186/s12284-022-00601-4

Wide Grain 3, a GRAS Protein, Interacts with DLT to Regulate Grain Size and Brassinosteroid Signaling in Rice

Rice (N Y). 2022 Nov 3;15(1):55. doi: 10.1186/s12284-022-00601-4.

Authors

Weilan Chen^#¹, Xiaoling Hu^#¹, Li Hu^#², Xinyue Hou¹, Zhengyan Xu¹, Fanmin Yang¹, Min Yuan¹, Feifan Chen¹, Yunxiao Wang¹, Bin Tu¹, Ting Li¹, Liangzhu Kang¹, Shiwen Tang¹, Bingtian Ma¹, Yuping Wang¹, Shigui Li¹, Peng Qin³, Hua Yuan⁴

Affiliations

¹ State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China.
² College of Agriculture, Forestry and Health, The Open University of Sichuan, 610073, Chengdu, Sichuan, China.
³ State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China. qinpeng@sicau.edu.cn.
⁴ State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China. yuanhua14536@sicau.edu.cn.

^# Contributed equally.

Abstract

Background: Grain size is a direct determinant of grain weight and yield in rice; however, the genetic and molecular mechanisms determining grain size remain largely unknown.

Findings: We identified a mutant, wide grain 3 (wg3), which exhibited significantly increased grain width and 1000-grain weight. Cytological analysis showed that WG3 regulates grain size by affecting cell proliferation. MutMap-based gene cloning and a transgenic experiment demonstrated that WG3 encodes a GRAS protein. Moreover, we found that WG3 directly interacts with DWARF AND LOW-TILLERING (DLT), a previously reported GRAS protein, and a genetic experiment demonstrated that WG3 and DLT function in a common pathway to regulate grain size. Additionally, a brassinosteroid (BR) sensitivity test suggested that WG3 has a positive role in BR signaling in rice. Collectively, our results reveal a new genetic and molecular mechanism for the regulation of grain size in rice by the WG3-DLT complex, and highlight the important functions of the GRAS protein complex in plants.

Conclusion: WG3 functions directly in regulating grain size and BR signaling in rice.

Keywords: Brassinosteroid signaling; DLT; GRAS; Grain size; Rice; WG3.

Publication types

Letter

Abstract

Publication types

Grants and funding