Overexpression of the Gene () Affects Leaf Margin Development in Transgenic .

BLADE-ON-PETIOLE 2 () plays a pivotal role in leaf morphogenesis. is a suitable model for exploring the molecular mechanisms underlying leaf serration formation, which are largely unknown. Here, we isolated the full-length gene and its promoter from and characterized its function in leaf morphogenesis through multidimensional approaches. The spatiotemporal expression pattern of indicated the high expression of in stems and leaf buds. We constructed promoter, fused the promoter sequences to the β-glucuronidase () gene, and then transformed them into . Histochemical GUS staining results indicated that activity was higher in petioles and the main vein. overexpression in caused moderate serration in the leaf tip, owing to the increased number of abnormal lamina epidermal cells and defective vascular tissue, thus indicating a novel role of . The ectopic expression of in promoted the expression of the lateral organ boundary gene ASYMMETRIC LEAVES2 () and inhibited JAGGED and CUP-SHAPED COTYLEDON2 () expression to establish leaf proximal-distal polarity. Moreover, participated in leaf serration formation by promoting the antagonistic relationship between and hormones during leaf margin development. Our findings revealed the role of in the proximal-distal polarity formation and development of leaf margin morphology, providing new insights into the regulatory mechanisms of the leaf formation development of .