The 14-3-3 protein GF14c acts as a negative regulator of flowering in rice by interacting with the florigen Hd3a

Abstract

Hd3a and FT proteins have recently been proposed to act as fl origens in rice and Arabidopsis, respectively; however, the molecular mechanisms of their function remain to be determined. In this study, we identifi ed GF14c (a 14-3-3 protein) as an Hd3a-interacting protein in a yeast twohybrid screen. In vitro and in vivo experiments, using a combination of pull-down assays and bimolecular fl uorescence complementation, confi rmed the interaction between Hd3a and GF14c. Functional analysis using either GF14c overexpression or knockout transgenic rice plants indicated that this interaction plays a role in the regulation of fl owering. GF14c-overexpressing plants exhibited a delay in fl owering and the knockout mutants displayed early fl owering relative to the wild-type plants under short-day conditions. These results suggest that GF14c acts as a negative regulator of fl owering by interacting with Hd3a. Since the 14-3-3 protein has been shown to interact with FT protein in tomato and Arabidopsis, our res lts in rice provide important fi ndings about FT signaling in plants.