查看文章

BOTRYTIS SUSCEPTIBLE1 INTERACTOR (BOI) and its three homologs (BOIs) are RING domain-containing proteins that repress flowering. Here, we investigated how BOIs repress flowering. Genetic analysis of the boiQ quadruple mutant indicates that BOIs repress flowering mainly through FLOWERING LOCUS T (FT). BOIs repress the expression of FT by CONSTANS (CO)-dependent and -independent mechanisms: in the CO-dependent mechanism, BOIs bind to CO, inhibit the targeting of CO to the FT locus, and thus repress the expression of FT; in the CO-independent mechanism, BOIs target the FT locus via a mechanism that requires DELLAs but not CO. This dual repression of FT makes BOIs strong repressors of flowering in both CO-dependent and CO-independent pathways in Arabidopsis thaliana. Our finding that BOIs inhibit CO targeting further suggests that, in addition to modulating CO mRNA …