Guangdong Provincial Key Laboratory for Plant Epigenetics, Longhua Bioindustry and Innovation Research Institute, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong, PR China.
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, PR China.
J Exp Bot. 2021 Feb 27;72(5):1809-1821. doi: 10.1093/jxb/eraa569.
Development of leaf margins is an important process in leaf morphogenesis. CIN-clade TCP (TEOSINTE BRANCHED1/CYCLOIDEA/PCF) transcription factors are known to have redundant roles in specifying leaf margins, but the specific mechanisms through which individual TCP genes function remain elusive. In this study, we report that the CIN-TCP gene TCP5 is involved in repressing the initiation and outgrowth of leaf serrations by activating two key regulators of margin development, the Class II KNOX factor KNAT3 and BEL-like SAW1. Specifically, TCP5 directly promotes the transcription of KNAT3 and indirectly activates the expression of SAW1. We also show that TCP5 regulates KNAT3 and SAW1 in a temporal- and spatial- specific manner that is largely in accordance with the progress of formation of serrations. This regulation might serve as a key mechanism in patterning margin morphogenesis and in sculpting the final form of the leaf.
叶片边缘的发育是叶片形态发生的一个重要过程。已知 CIN-clade TCP（TEOSINTE BRANCHED1/CYCLOIDEA/PCF）转录因子在指定叶片边缘方面具有冗余作用，但单个 TCP 基因发挥作用的具体机制仍不清楚。在这项研究中，我们报告 CIN-TCP 基因 TCP5 通过激活两个关键的边缘发育调节剂，即 II 类 KNOX 因子 KNAT3 和 BEL-like SAW1，参与抑制叶片锯齿的起始和生长。具体来说，TCP5 直接促进 KNAT3 的转录，并间接激活 SAW1 的表达。我们还表明，TCP5 以时间和空间特异性的方式调节 KNAT3 和 SAW1，这与锯齿形成的进展基本一致。这种调控可能是模式化边缘形态发生和塑造叶片最终形态的关键机制。
