Tillering and small grain 1 dominates the tryptophan aminotransferase family required for local auxin biosynthesis in rice  

作　　者：Tao Guo Ke Chen Nai-Qian Dong Wang-Wei Ye Jun-Xiang Shan Hong-Xuan Lin 

机构地区：[1]National Key Laboratory of Plant Molecular Genetics,CAS Centre for Excellence in Molecular Plant Sciences and Collaborative Innovation Center of Genetics&Development,Shanghai Institute of Plant Physiology&Ecology,Shanghai Institute for Biological Sciences,Chinese Academy of Sciences,Shanghai 200032,China [2]University of the Chinese Academy of Sciences,Beijing 100049,China [3]School of Life Science and Technology,ShanghaiTech University,Shanghai 201210,China

出　　处：《Journal of Integrative Plant Biology》2020年第5期581-600,共20页植物学报（英文版）

基　　金：supported by grants from the Ministry of Science and Technology of China(2016YFD0100902);Chinese Academy of Sciences(QYZDY-SSW-SMC023,XDB27010104);National Natural Science Foundation of China(31788103);China Postdoctoral Science Foundation(2018M642102);the Shanghai Science and Technology Development(18JC1415000);National Key Laboratory of Plant Molecular Genetics.

摘　　要：Auxin is a crucial phytohormone,controlling multiple aspects of plant growth and responses to the changing environment.However,the role of local auxin biosynthesis in specific developmental programs remains unknown in crops.This study characterized the rice tillering and small grain 1(tsg1)mutant,which has more tillers but a smaller panicle and grain size resulting from a reduction in endogenous auxin.TSG1 encodes a tryptophan aminotransferase that is allelic to the FISH BONE(FIB)gene.The tsg1 mutant showed hypersensitivity to indole-3-acetic acid and the competitive inhibitor of aminotransferase,L-kynurenine.TSG1 knockout resulted in an increased tiller number but reduction in grain number and size,and decrease in height.Meanwhile,deletion of the TSG1 homologs OsTAR1,Os TARL1,and OsTARL2 caused no obvious changes,although the phenotype of the TSG1/Os TAR1 double mutant was intensified and infertile,suggesting gene redundancy in the rice tryptophan aminotransferase family.Interestingly,TSG1 and Os TAR1,but not Os TARL1 and OsTARL2,displayed marked aminotransferase activity.Meanwhile,subcellular localization was identified as the endoplasmic reticulum,while phylogenetic analysis revealed functional divergence of TSG1 and OsTAR1 from OsTARL1 and OsTARL2.These findings suggest that TSG1 dominates the tryptophan aminotransferase family,playing a prominent role in local auxin biosynthesis in rice.

关 键 词：GRAIN LOCAL AUXIN 

分 类 号：S511[农业科学—作物学]