Fenoxycarb, a carbamate insect growth regulator, inhibits brassinosteroid action

Brassinosteroids (BRs) are steroid hormones that regulate plant growth, development, and stress resistance. In this study, we evaluated the effect of agrochemicals on dark-induced hypocotyl elongation, which is regulated by BRs, to identify novel chemicals BR action. We found juvenile hormone agonist fenoxycarb inhibited elongation in Arabidopsis. Treatment with same class agonist, pyriproxyfen, did not affect elongation. Co-treatment partly canceled fenoxycarb-induced suppression. addition, gene expression analysis revealed altered BR-responsive expression. These results indicate a action inhibitor.