Functional characterization of IiAGAMOUS from Isatis indigotica in floral development

The coding sequence of IiAGAMOUS in Isatis indigotica was cloned in the present work. Amino acid sequence alignment showed that the C-terminus of IiAGAMOUS contains two conserved motifs, AGⅠ and AGⅡ, which are related with the specific functions of AGAMOUS-like proteins. IiAGAMOUS was highly expressed in stamen and pistil, and IiAGAMOUS was localized to the nucleus. The results of yeast two-hybrid and bimolecular fluorescence complementation experiments showed that IiAGAMOUS was able to interact with IiSEP3. Point mutation of leucines in K3 subdomain of IiAGAMOUS showed that the 172nd leucine played a key role in interaction with IiSEP3. Ectopic expression of IiAGAMOUS in Arabidopsis resulted in early flowering. Abnormal phenotypes were found in the stamens and pistils of the 35S::IiAGAMOUS transgenic lines. This study is conducive to further understanding the roles of AGAMOUS-like proteins in floral organ development.