背景+问题：Branching determines cotton architecture and production, but the underlying regulatory mechanisms remain unclear. 

主要发现：Here, we report that the miR164‐GhCUC2 (CUP‐SHAPED COTYLEDON2) module regulates lateral shoot development in cotton and Arabidopsis. 

研究材料：We generated OE‐GhCUC2m (overexpression GhCUC2m) and STTM164 (short tandem target mimic RNA of miR164) lines in cotton and heterologous expression lines for gh‐miR164, GhCUC2 and GhCUC2m in Arabidopsis to study the mechanisms controlling lateral branching.

结果1-miR164-GhCUC2模块功能：GhCUC2m overexpression resulted in a short‐ranch phenotype similar to STTM164. In addition, heterologous expression of GhCUC2m led to decreased number and length of branches compared with wild type, opposite to the effects of the OE‐gh‐pre164 line in Arabidopsis. 

结果2-GhCUC2下游GhBRC1：GhCUC2 interacted with GhBRC1 and exhibited similar negative regulation of branching. Overexpression of GhBRC1 in the brc1‐2 mutant partially rescued the mutant phenotype and decreased branch number. 

结果3-GhBRC1下游NCED1：GhBRC1 directly bound to the NCED1 promoter and activated its transcription, leading to local abscisic acid (ABA) accumulation and response. Mutation of the NCED1 promoter disrupted activation by GhBRC1. 

结论：This finding demonstrates a direct relationship between BRC1 and ABA signalling and places ABA downstream of BRC1 in the control of branching development. The miR164‐GhCUC2‐GhBRC1‐GhNCED1 module provides a clear regulatory axis for ABA signalling to control plant architecture.

 摘 要 

分枝决定了棉花的结构和产量，但是潜在的分子机制还不清楚。本文中，作者报道了miR164‐GhCUC2模块在棉花和拟南芥中均可调控侧枝的发育。作者首先在棉花中获得了过表达GhCUC2m的OE‐GhCUC2m株系和表达mimic miR164的STTM164株系，而在拟南芥中则获得了gh‐miR164、GhCUC2和GhCUC2m异源表达株系，用以进行侧生分枝的研究。GhCUC2m过表达会导致短枝的表型，这与STTM164的表型相似。另外，异源表达GhCUC2m会导致拟南芥的分枝数量减少、长度缩短，与OE‐gh‐pre164株系的表型相反。GhCUC2能够与GhBRC1发生互作，对分枝性状起负调控作用。在brc1‐2突变体中，过表达GhBRC1能够部分恢复突变体的表型，减少分枝数目。GhBRC1能够直接结合到NCED1基因的启动子区，并激活该基因的转录，导致局部的ABA积累和响应。NCED1启动子的突变会干扰由GhBRC1介导的激活。本文的研究结果揭示了BRC1与ABA信号转导之间直接的关联，并且明确了ABA在分枝发育过程中于BRC1基因的下游发挥作用。因此，miR164‐GhCUC2‐GhBRC1‐GhNCED1模块为ABA信号转导控制植株结构提供了一个明确的调控轴。