Gibberellin repression of axillary bud formation in Arabidopsis by modulation of DELLA-SPL9 complex activity  

作　　者：Qi-Qi Zhang Jia-Gang Wang Ling-Yan Wang Jun-Fang Wang Qun Wang Ping Yu Ming-Yi Bai Min Fan 

机构地区：[1]Key Laboratory of Plant Development and Environmental Adaptation Biology,Ministry of Education,School of Life Sciences,Shandong University,Qingdao 266237,China

出　　处：《Journal of Integrative Plant Biology》2020年第4期421-432,共12页植物学报（英文版）

基　　金：funded by the Shandong Province Natural Science Foundation(JQ201708 and 2018GHZ007);by the Ministry of Science and Technology of China(2013CB967300);by the National Natural Science Foundation of China(31470376,31670284 and 31600199);by the China Postdoctoral Science Foundation(2017M612259 and 2018T110684 to J.W.);by the Shandong Province Postdoctoral Science Foundation(11200078311023 to J.W.)。

摘　　要：The formation of lateral branches has an important and fundamental contribution to the remarkable developmental plasticity of plants,which allows plants to alter their architecture to adapt to the challenging environment conditions.The Gibberellin(GA)phytohormones have been known to regulate the outgrowth of axillary meristems(AMs),but the specific molecular mechanisms remain unclear.Here we show that DELLA proteins regulate axillary bud formation by interacting and regulating the DNA-binding ability of SQUAMOSA-PROMOTER BINDING PROTEIN LIKE 9(SPL9),a micro RNA156-targeted squamosa promoter binding protein-like transcription factor.SPL9 participates in the initial regulation of axillary buds by repressing the expression of LATERAL SUPPRESSOR(LAS),a key regulator inthe initiation of AMs,and LAS contributes to the specific expression pattern of the GA deactivation enzyme GA2ox4,which is specifically expressed in the axils of leaves to form a low-GA cell niche in this anatomical region.Nevertheless,increasing GA levels in leaf axils by ectopically expressing the GA-biosynthesis enzyme GA20ox2 significantly impaired axillary meristem initiation.Our study demonstrates that DELLA-SPL9-LAS-GA2ox4 defines a core feedback regulatory module that spatially pattern GA content in the leaf axil and precisely control the axillary bud formation in different spatial and temporal.

关 键 词：SPL9 IMPAIRED spatially 

分 类 号：Q945[生物学—植物学]