Arabidopsis microtubule-BRI1-associated proteins negatively regulate hypocotyl elongation by controlling brassinosteroid-dependent cortical microtubule reorientation.

ABSTRACT: Brassinosteroids (BRs) are steroid-type phytohormones that are essential for plant growth, development, and adaptation to environmental stresses. BRs are known to control microtubule (MT) orientation, which is pivotal for directional growth, but the underlying molecular mechanisms are still largely unknown. Here, we identified and characterized a new family of BRI1-interacting proteins named MICROTUBULE-BRI1-ASSOCIATED PROTEINS (MBAPs). We confirmed, using several complementary approaches, that MBAPs are genuine BRI1 partners in plant cells. We demonstrated that MBAPs localize to cortical microtubules (CMTs) underlying the plasma membrane using a short conserved helix, where they make contact with BRI1. Combinations of mbap loss-of-function mutants showed hypersensitivity to BRs and establ

SUBMITTER: Delesalle C 

PROVIDER: S-EPMC12903448 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature