Function of Botrytis Susceptible1 Interactor (BOI) in regulating flowering time in Arabidopsis thaliana

Abstract

    A Really Interesting New Gene (RING) finger protein BOTRYTIS SUSCEPTIBLE1 INTERACTOR (BOI) represses the expression of the Flowering Locus T gene (FT) in Arabidopsis thaliana, hence the inhibition of flowering in long days. To investigate the molecular function of BOI, we studied the interaction of BOI with a histone deacetylase complex (HDAC) since this complex also acts as a repressive regulator of FT expression. Here, we report that BOI directly interacted with HISTONE DEACETYLASE 6 (HDA6), an enzyme subunit of HDAC in yeast and in vitro. A yeast bihybrid assay showed that yeast cells containing both BOI and HDA6 were able to grow on a selective medium without tryptophan, leucine, adenine và histidine, indicating a direct interaction of BOI and HDA6 in yeast. In addition, BOI also bound to gluthathion S-transferase (GST)-HDA6 but not to GST in an in vitro pull-down assay. These results suggest BOI might interact with HDAC to inhibit the expression of FT in Arabidopsis. Further in vivo studies are needed to uncover this molecular mechanism.