BEAR1, a bHLH transcription factor, controls seedling growth by regulating gibberellins biosynthesis in rice  

作　　者：Yantong Teng Maohong Cai Qinyu Xie Qinglong Liu Haiwen Zhang Tao Chen 

机构地区：[1]Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants,College of Life and Environmental Science,Hangzhou Normal University,Hangzhou 311121,Zhejiang,China [2]College of Life Sciences,Inner Mongolia University,Hohhot 010021,Inner Mongolia,China [3]Institute of Crop and Nuclear Technology Utilization,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,Zhejiang,China [4]Biotechnology Research Institute,Chinese Academy of Agricultural Sciences,Beijing 100081,China

出　　处：《The Crop Journal》2023年第3期744-755,共12页作物学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(32071932);Scientific Research Foundation for Scholars of HZNU(2019QDL015);the Natural Science Foundation of Zhejiang province(LQ22C130001)。

摘　　要：The genetic pathways of rice seedling growth have a major impact on seedling emergence from soil and development.In this study,we identified a new bHLH transcription factor,BEAR1,from rice RNAi mutant library.Both the BEAR1-RNAi and bear1 CRISPR mutants had accelerated seedling growth.Histological section of leaves showed accelerated development of lacuna and vascular bundles in bear1 mutant.GUS staining revealed that BEAR1 was highly expressed in coleoptiles and leaves at seedling stage.Expression analysis of gibberellin(GA)biosynthesis and metabolic genes and content determination of active GAs indicated that the expression of GA biosynthesis genes,especially OsKS4 and OsCPS2,were upregulated and the GAs content were significantly increased in bear1,which correlated with the seedling phenotype of bear1 mutant.Molecular and biochemical assays revealed that BEAR1 directly binds to the promoter of OsKS4,thereby repressing its expression.Haplotypes analysis showed clear differentiation in indica and japonica rice varieties,and a strong correlation with seedling height.These findings provide novel insights into the regulation of seedling growth in rice.

关 键 词：RICE BEAR1 Seedling growth GIBBERELLINS OsKS4 

分 类 号：S511[农业科学—作物学]