Characterization of the Gene Family and its Putative Involvement of Tuberous Root Shape in Radish.

The shape of the tuberous root, a very important quality trait, varies dramatically among radish cultivars. Ovate family proteins () are plant-specific proteins that regulate multiple aspects of plant growth and development. To investigate the possible role of in radish tuberous root formation, 35 putative were identified from radish, and their expression patterns were detected during tuberous root development in six different radish cultivars. Phylogenetically, clustered together with and other members of this family that are known to regulate organ shape. Moreover, expression was negatively correlated with tuberous root elongation after the cortex splitting stage, which made this gene the top candidate for the involvement of tuberous root shape. To further characterize the function of , it was ectopically expressed in Arabidopsis. overexpression in Arabidopsis led to multiple phenotypical changes, especially the decreased length and increased width of the hypocotyl. Furthermore, expression was induced by all the five classic plant hormones except ethylene, and it was most sensitive to exogenous gibberellic acid treatment. We also found that was localized in the cytoplasm. Taken together, our results suggested the possible involvement for in suppressing radish tuberous root elongation and that it encodes a functional protein which mainly inhibits the elongation of Arabidopsis aerial organs.