Ectopic Expression of a Pak-choi YABBY Gene, BcYAB3, Causes Leaf Curvature and Flowering Stage Delay in Arabidopsis thaliana

The YABBY family are a group of seed plant-specific transcription factors, which are involved in the specification of abaxial polarity in lateral organs. In , () plays a critical role in regulating abaxial patterning, growth of lateral organs, and inflorescence phyllotaxy. In this study, the gene was isolated from Pak-choi ( subsp. ). The tissue-specific expression analysis indicated that the gene has significantly high transcript levels in stem, leaf, and flower. We investigated the subcellular localization of BcYAB3 and found the protein to be expressed in the nucleus. In the transgenic plants expressing the gene, the leaves were curling downward with the plant growth, and the bolting and flowering stages were delayed. These results not only validate the function of in the leaf and flower development in , but also contribute to unravel the molecular regulatory mechanism of gene in the establishment of adaxial-abaxial polarity of the lateral organs in Pak-choi.