TATA-box binding protein-associated factor 2 regulates grain size in rice
Ling Jiang,
Ning Jiang,
Zejun Hu,
Xuejun Sun,
Xian Xiang,
Yahui Liu,
Mingwei Wu,
Chunming Liu,
Xiaojin Luo
Affiliations
Ling Jiang
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai 200438, China
Ning Jiang
State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai 200438, China
Zejun Hu
State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai 200438, China
Xuejun Sun
State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai 200438, China
Xian Xiang
State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai 200438, China
Yahui Liu
State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai 200438, China
Mingwei Wu
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
Chunming Liu
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; School of Advanced Agricultural Sciences, Peking University, Beijing 100871, China; Corresponding authors.
Xiaojin Luo
State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai 200438, China; Corresponding authors.
Grain size, characterized by a combination of grain length, width, and thickness, is one of the major determinants of yield in rice. The present study identified TATA-box binding protein-associated factor 2 (TAF2) as an essential component regulating transcription and determining grain size in rice. Map-based cloning showed that a G/T substitution in TAF2 resulted in a naturally occurring mutant called reduced grain size and plant height 1 (rgh1). The mutants, with weak edited rgh1 alleles, exhibited a small grain phenotype with reduced grain length and width, while the severe knockout mutant (rgh1-2s) was dwarf and completely sterile. Allelic test performed between rgh1 and several edited alleles confirmed that the mutation in TAF2 caused the rgh1 phenotype. GUS staining showed that TAF2 was mainly expressed in the vascular bundles of roots, stems, leaves, and grains. The cytological analysis revealed that reduced cell division in the glumes resulted in the small grain phenotype of rgh1. Further RNA-sequencing detected altered expression of genes involved in the basic biological processes in rgh1 mutant. These findings provide novel insights into the TAF2-mediated genetic mechanism regulating grain size in rice.
