Control of Plant Branching by the CUC2/CUC3-DA1-UBP15 Regulatory Module

First author: Yu Li; Affiliations: CAS Institute of Genetics and Developmental Biology (中科院遗传与发育生物学研究所): Beijing, China

Corresponding author: Yunhai Li

Plant lateral branches are important for plant architecture and plant production, but how plants determine their lateral branches remains to be further understood. Here we report that the CUC2/3-DA1-UBP15 regulatory module controls the initiation of axillary meristems, thereby determining the number of lateral branches in Arabidopsis. Mutation in the ubiquitin-dependent peptidase DA1 causes fewer lateral branches due to defects in the initiation of axillary meristems. The transcription factors CUC2 and CUC3, which regulate the axillary meristem initiation, directly bind to the DA1 promoter and activate its expression. Further results show that the ubiquitin specific protease UBP15, which is a direct substrate of DA1 peptidase, represses the initiation of axillary meristems. Genetic analyses support that CUC2/3, DA1, and UBP15 function, at least in part, in a common pathway to regulate the initiation of axillary meristems. Therefore, our findings discover a novel genetic and molecular framework by which the CUC2/3-DA1-UBP15 regulatory module controls the initiation of axillary meristems, thereby determining plant architecture.

植物侧枝对于植物株型结构和植物产量是非常重要的，但植物如何决定其自身的侧枝还有待进一步研究。本文中，作者报道了拟南芥中CUC2/3-DA1-UBP15调控模块控制腋生分生组织的起始，因此决定了侧枝的数量。泛素依赖性肽酶DA1的突变导致腋生分生组织对的起始存在缺陷，从而减少了侧枝的数量。转录因子CUC2/3作用于腋生分生组织的起始，会直接结合到DA1的启动子上并激活DA1的表达。进一步的研究显示DA1肽酶的直接底物泛素特异性蛋白酶UBP15能够抑制腋生分生组织的起始。遗传分析显示CUC2/3、DA1以及UBP15在同一条通路上发挥作用，调控腋生分生组织的起始。因此，本文的发现揭示了一个新的遗传和分子框架，其中CUC2/3-DA1-UBP15调控模块控制腋生分生组织的起始，从而决定植物的株型结构。

通讯：李云海  (http://pcce.genetics.cas.cn/experts/PI/lyh/introduction/)

个人简介：1996年，河南大学，学士；1999年，中国水稻研究所，硕士；2003年，中国科学院遗传所，博士；2003-2008年，英国John Innes Centre，博士后。

研究方向：单、双子叶植物（水稻和拟南芥）种子和器官大小调控的分子机理研究。

doi: https://doi.org/10.1105/tpc.20.00012

Journal: Plant Cell

Published date: April 02, 2020

p.s. 通讯往期文章链接：

Annual Review of Plant Biology：植物种子大小的分子调控网络综述

PLoS Genetics：SAP基因调控拟南芥的器官大小