Isolation and Functional Analysis of Homolog From .

() homologs are crucial regulators of flower development in angiosperms. In this study, we isolated the homolog from , a basal angiosperm belonging to the Magnoliaceae. Molecular phylogenetic analysis suggested that was grouped into the PI/GLO lineages of B-class MADS-box gene with the distinctive PI motif. Further expression profiling analysis showed that was expressed in tepals and stamens but not in juvenile leaves and carpels, similar to the spatial expression pattern of in Arabidopsis. Interestingly, had higher expression level in inner-tepals than in outer-tepals, whereas the flower is homochlamydeous. Moreover, ectopic expression of in Arabidopsis mutant emerged filament-like structures but had no obvious petals, suggesting a partial phenotypic recovery of mutant. The features of in the expression pattern and gene function improved our acknowledgment of B-class genes in , and contributed to the clarification of evolution status and relations with other sibling species in molecular perspective.