State Key Laboratory of Plant Cell and Chromosome Engineering, Chinese Academy of Sciences Centre for Excellence in Molecular Plant Science, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
University of Chinese Academy of Sciences, Beijing 100039, China.
Plant Cell. 2020 Jun;32(6):1919-1932. doi: 10.1105/tpc.20.00012. Epub 2020 Apr 2.
Lateral branches are important for plant architecture and production, but how plants determine their lateral branches remains to be further understood. Here, we report that the CUP-SHAPED COTYLEDON2 (CUC2)/CUC3-DA1-UBIQUITIN-SPECIFIC PROTEASE15 (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 promoter and activate its expression. Further results show that UBP15, which is a direct substrate of DA1 peptidase, represses the initiation of axillary meristems. Genetic analyses support that CUC2/CUC3, DA1, and UBP15 function, at least in part, in a common pathway to regulate the initiation of axillary meristems. Therefore, our findings establish a genetic and molecular framework by which the CUC2/CUC3-DA1-UBP15 regulatory module controls the initiation of axillary meristems, thereby determining plant architecture.
侧枝对植物的结构和产量很重要，但植物如何决定其侧枝仍然需要进一步研究。在这里，我们报告 CUP-SHAPED COTYLEDON2 (CUC2)/CUC3-DA1-Ubiquitin-Specific Protease15 (UBP15) 调控模块控制侧芽分生组织的起始，从而决定拟南芥侧枝的数量。由于侧芽分生组织起始缺陷，泛素依赖性肽酶 DA1 的突变导致侧枝数量减少。转录因子 CUC2 和 CUC3 调节侧芽分生组织的起始，它们直接结合到 启动子并激活其表达。进一步的结果表明，作为 DA1 肽酶的直接底物，UBP15 抑制侧芽分生组织的起始。遗传分析支持 CUC2/CUC3、DA1 和 UBP15 至少部分在共同途径中发挥作用，以调节侧芽分生组织的起始。因此，我们的研究结果建立了一个遗传和分子框架，CUC2/CUC3-DA1-UBP15 调控模块通过控制侧芽分生组织的起始，从而决定植物的结构。
