Roles of miR319-regulated TCPs in plant development and response to abiotic stress

Abstract Elaborate regulation of gene expression is required for plants to maintain normal growth, development, and reproduction. MicroRNAs (miRNAs) and transcription factors are key players that control gene expression in plant regulatory networks. The TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) family comprises plant-specific transcription factors that contain a conserved TCP domain of 59 amino acids. Some members of this family are targeted by miR319, one of the most ancient and evolutionarily conserved miRNAs in plants. Accumulating evidence has revealed that miR319-regulated TCP (MRTCP) genes participate extensively in plant development and responses to environmental stress. In this review, the structural characteristics and classifications of TCP transcription factors and the regulatory relationships between TCP transcription factors and miRNAs are introduced. Current knowledge of the regulatory functions of MRTCP genes in multiple biological pathways including leaf development, vascular formation, flowering, hormone signaling, and response to environmental stresses such as cold, salt, and drought is summarized. This review will be beneficial for understanding the roles of the MRTCP-mediated regulatory network and its molecular mechanisms in plant development and stress response, and provides a theoretical basis for plant genetic improvement.