title: Auxins increase expression of the brassinosteroid receptor and brassinosteroid-responsive genes in Arabidopsis.
abstract: Auxins and brassinosteroids are essential phytohormones that synergistically regulate physiological and developmental processes in plants. Previously, we demonstrated that auxins stimulate brassinosteroid perception by regulating the level of brassinosteroid receptor in rice. Here we showed that auxin treatment increased expression of the Arabidopsis brassinosteroid receptor gene BRI1. The promoter of BRI1 has an auxin-response element that is targeted by auxin-response factor transcription factors. Auxin pretreatment increased the sensitivity to brassinosteroids of brassinosteroid-responsive genes. Although multilevel interactions between auxins and brassinosteroids have previously been reported, our findings suggest a possibility that auxins control the degree of brassinosteroid perception by regulating the expression of gene for brassinosteroid receptor, and this phenomenon is conserved between monocots (rice) and dicots (Arabidopsis).
authors: Faculty of Bioresources and Environmental Sciences; Ishikawa Prefectural University; Ishikawa, Japan.
authors: Tomoaki
authors: T
authors: Sakamoto
authors: Shozo
authors: S
authors: Fujioka
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D060406:Brassinosteroids / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism* / Q000494:pharmacology; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010937:Plant Growth Regulators / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D020218:Response Elements; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D014157:Transcription Factors
keywords: ARF; Arabidopsis; AuxRE; auxin; brassinosteroid; transcriptional regulation