Actin Cytoskeleton Integrates Auxin and Brassinosteroid Signaling in Plants.

We describe a new mutant allele of the ACTIN2 gene with enhanced actin dynamics, displaying a broad array of twisting and bending phenotypes that resemble BR-treated plants. Moreover, auxin transcriptional regulation is enhanced on the mutant background, supporting the idea that shaping actin filaments is sufficient to modulate BR-mediated auxin responsiveness. The actin cytoskeleton thus functions as a scaffold for integration of auxin and BR signaling pathways. Three biological replicates were performed for each sample (wild-type and actin2-5) and hybridized to the the Affymetrix ATH1 GeneChips.