Abstract
Tiller angle is a key agricultural trait that estab-lishes 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 un-known.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 dramati-cally 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 var-iation 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.Over-expression of BTA2 significantly increased grain yield in the elite rice cultivar Huanghuazhan under appropriate dense planting conditions.Our find-ings 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.
基金项目
Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021JJLH0045)
Natural Science Foundation of Zhejiang Province(LTGN23C130001)
National Key R&D Program of China(2020YFE0202300)
Key Research and Development Program of Zhejiang Province(2021C02056)
Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2013-CNRRI)
维普
万方数据