BTA2 regulates tiller angle and the shoot gravity response through controlling auxin content and distribution in rice  

作　　者：Zhen Li Junhua Ye Qiaoling Yuan Mengchen Zhang Xingyu Wang Jing Wang Tianyi Wang Hongge Qian Xinghua Wei Yaolong Yang Lianguang Shang Yue Feng 

机构地区：[1]China National Center for Rice Improvement,State Key Laboratory of Rice Biology and Breeding,China National Rice Research Institute,Hangzhou 310006,China [2]Shenzhen Branch,Guangdong Laboratory of Lingnan Modern Agriculture,Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs,Agricultural Genomics Institute at Shenzhen,Chinese Academy of Agricultural Sciences,Shenzhen 518124,China [3]National Nanfan Research Institute(Sanya),Chinese Academy of Agricultural Sciences,Sanya 572024,China

出　　处：《Journal of Integrative Plant Biology》2024年第9期1966-1982,共17页植物学报（英文版）

基　　金：supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021JJLH0045);the Natural Science Foundation of Zhejiang Province(LTGN23C130001);National Key R&D Program of China(2020YFE0202300);the Key Research and Development Program of Zhejiang Province(2021C02056);the Agricultural Science and Technology Innovation Program(CAAS‐ASTIP‐2013‐CNRRI).

摘　　要：Tiller angle is a key agricultural trait that establishes plant architecture,which in turn strongly affects grain yield by influencing planting density in rice.The shoot gravity response plays a crucial role in the regulation of tiller angle in rice,but the underlying molecular mechanism is largely unknown.Here,we report the identification of the BIG TILLER ANGLE2(BTA2),which regulates tiller angle by controlling the shoot gravity response in rice.Loss-of-function mutation of BTA2 dramatically reduced auxin content and affected auxin distribution in rice shoot base,leading to impaired gravitropism and therefore a big tiller angle.BTA2 interacted with AUXIN RESPONSE FACTOR7(ARF7)to modulate rice tiller angle through the gravity signaling pathway.The BTA2 protein was highly conserved during evolution.Sequence variation in the BTA2 promoter of indica cultivars harboring a less expressed BTA2 allele caused lower BTA2 expression in shoot base and thus wide tiller angle during rice domestication.Overexpression of BTA2 significantly increased grain yield in the elite rice cultivar Huanghuazhan under appropriate dense planting conditions.Our findings thus uncovered the BTA2-ARF7 module that regulates tiller angle by mediating the shoot gravity response.Our work offers a target for genetic manipulation of plant architecture and valuable information for crop improvement by producing the ideal plant type.

关 键 词：AUXIN DOMESTICATION gravity response RICE tiller angle 

分 类 号：S511[农业科学—作物学]