Overexpression of the mango MiGF6A and MiGF6B genes promotes early flowering in transgenic Arabidopsis plants

Abstract

14-3-3 genes are universal regulators that play important roles in regulating flower development and stress responses. In this study, two homologous 14-3-3 genes, MiGF6A and MiGF6B, were obtained from the genome of SiJiMi mango. Sequence analysis showed that both MiGF6A and MiGF6B have a fully conserved 14-3-3 superfamily domain. MiGF6A and MiGF6B were expressed in tissues at all stages of development, especially in the flowers and buds. Both MiGF6A and MiGF6B were expressed in response to low temperature, NaCl and polyethylene glycol (PEG) treatments. Subcellular localization analysis showed that MiGF6A and MiGF6B were located in the nucleus. Overexpression of MiGF6A and MiGF6B in Arabidopsis thaliana resulted in an early-flowering phenotype and significant upregulation of the flowering-related genes FLOWERING LOCUS T (AtFT), AtFD1, and LEAFY (AtLFY). Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) analyses showed that MiGF6A and MiGF6B interact with the MiFD1, MiFD2 and MiSVP3 proteins. These results suggest that MiGF6A and MiGF6B may play positive roles in the mango flowering process.