CONTROL OF THE FLORAL TRANSITION BY TWO HOMOLOGS WD-REPEAT PROTEINS IN ARABIDOPSIS

Abstract

We previously found one homolog of the yeast SWD2 protein in Arabidopsis, named SDW2A. Initial experiments showed that SWD2A promotes flowering in both long and short day conditions. Hence, we continue studying on another SWD2 homolog in Arabidopsis ¿ the SWD2B gene - to investigate functions of SWD2 genes in the floral transition. We have found that SWD2B represses the expression of the floral repressor FLC and its homologs to promote flowering in long day conditions. In addition, our further study on SWD2A revealed that SWD2A plays an additive role with FLD, FVE and FRI in floral transition. In conclusion, we described two SWD2 homologs regulating floral integrators in Arabidopsis. More importantly, we identified that FLC and its clade members are the targets of SWD2A and SWD2B. Thus, SWD2s are new regulators of the floral transition.