Verification of gene function and interaction protein of PhPIF4

Abstract

In order to investigate the molecular mechanism of PhPIF4 in response to gibberellin-regulated floral transition of Phalaenopsis, qRT-PCR and functional verification experiment of transgenic Arabidopsis thaliana was carried out, and the results showed that PhPIF4 expression was significantly increased in flower buds, leaves and roots after spraying with growth regulator GA3. In PhPIF4 overexpressed Arabidopsis thaliana, hypocotyl elongation, early flowering and increased flowering amount were observed, especially after exogenous GA3 treatment. The content of the endogenous hormone GA3 in the transgenic Arabidopsis thaliana was higher. The interaction between PhDELLA and PhPIF4 was verified by Y2H experiment. The Y1H test demonstrated that PhDELLA could not interact with the PhPIF4 promoter but PhMYB which plays an important role in the regulation of flower development and flowering time could interacte with the PhPIF4 promoter. These findings indicated PhPIF4 participated in the flowering transition and might be directly regulated by GA and the PhPIF4 protein interacts with PhDELLA to go through the GA signaling pathway and the PhPIF4 gene was regulated by PhMYB.