Brassinosteroid signaling mutants bil2 and bil5 suppressors

Abstract

We had identified brassinosteroid biosynthesis inhibitor Brz insensitive mutant bil1 from EMS-mutation lines, and bil5 from fast neutron-mutation lines. To identify additional components of the brassinosteroid signaling, trial to screen new mutants as Brz-insesitive-long hypocotyls in the dark was applied to Arabidopsis activation-tag lines. We screened Arabidopsis activation-tag lines and isolated bil2 that showed long hypocotyls on the medium containing Brz in the dark. Light-grown bil2 mutants had long petiole phenotype similar to wild-type plants treated with brassinosteroid or BRI1-ox mutants. These phenotypes suggested that bil2 mutants enhanced the brassinosteroid signaling. Identification of overexpressing the bil2 candidate gene is progress.