Characterization of SUPPRESSOR OF EARLY FLOWERING 3 7 (SEL7) which encodes a polyA binding protein and regulates flowering time through a floral repressor FLC in Arabidopsis

Abstract

The transition to flowering is a crucial moment in a plant life cycle. To understand the molecular mechanisms for switching flowering time by different photoperiod in Arabidopsis, genetic and molecular analyses using elf3-1 have been performed. In a screen for late flowering, after mutagenesis by heavy ion beams of elf3-1, a novel mutant, suppressor of early flowering 3 7 (sel7) was identified. sel7;elf3-1 dramatically delayed flowering under continuous light compared to short-day. Molecular analyses indicated that SEL7 was most closely associated with the autonomous pathway. Indeed, mRNA level of a floral repressor FLC, which acts within this pathway was up-regulated in sel7;elf3-1, whereas those of FT and SOC1 was decreased. Combination of genetic mapping, sequencing and gene expression analysis of 53 candidate genes revealed that sel7 was a novel inversion mutation within the PAB3 gene. Although the enhancement in FLC mRNA level is likely to contribute to the sel7;elf3-1 phenotype, our data suggest that SEL7/PAB3 also promotes flowering independently of FLC.