The dual role of casein kinase 1, DTG1, in regulating tillering and grain size in rice
Jijin Li,
Dan Zhou,
Deke Li,
Gen Wang,
Rui Qin,
Chengqin Gong,
Kang Chen,
Yunqing Tong,
Lingfeng Li,
Keke Liu,
Jiangkun Ye,
Binjiu Luo,
Chenglong Jiang,
Haipeng Wang,
Jinghua Jin,
Qiming Deng,
Shiquan Wang,
Jun Zhu,
Ting Zou,
Shuangcheng Li,
Ping Li,
Yueyang Liang
Affiliations
Jijin Li
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China; Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Dan Zhou
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Deke Li
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Gen Wang
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Rui Qin
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Chengqin Gong
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Kang Chen
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Yunqing Tong
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Lingfeng Li
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Keke Liu
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Jiangkun Ye
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Binjiu Luo
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Chenglong Jiang
Nanchong Academy of Agricultural Science, Nanchong 637000, Sichuan, China
Haipeng Wang
Neijiang Academy of Agricultural Science, Neijiang 641000, Sichuan, China
Jinghua Jin
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Qiming Deng
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Shiquan Wang
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Jun Zhu
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Ting Zou
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Shuangcheng Li
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Ping Li
Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China; Corresponding authors.
Yueyang Liang
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China; Corresponding authors.
Tiller number and grain size are important agronomic traits that determine grain yield in rice. Here, we demonstrate that DEFECTIVE TILLER GROWTH 1 (DTG1), a member of the casein kinase 1 protein family, exerts a co-regulatory effect on tiller number and grain size. We identified a single amino acid substitution in DTG1 (I357K) that caused a decrease in tiller number and an increase in grain size in NIL-dtg1. Genetic analyses revealed that DTG1 plays a pivotal role in regulation of tillering and grain size. The DTG1I357K allelic variant exhibited robust functionality in suppressing tillering. We show that DTG1 is preferentially expressed in tiller buds and young panicles, and negatively regulates grain size by restricting cell proliferation in spikelet hulls. We further confirm that DTG1 functioned in grain size regulation by directly interacting with Grain Width 2 (GW2), a critical grain size regulator in rice. The CRISPR/Cas9-mediated elimination of DTG1 significantly enhanced tiller number and grain size, thereby increasing rice grain yield under field conditions, thus highlighting potential value of DTG1 in rice breeding.
