title: Homeostasis of brassinosteroids regulated by DRL1, a putative acyltransferase in Arabidopsis.
abstract: Brassinosteroids (BRs) play essential roles in regulating various aspects of plant growth and development and in responding to diverse environmental cues, and their metabolism is an important way to regulate their homeostasis in plants. Here, we identified a dominant mutant, dwarf and round leaf-1 (drl1-D), which exhibits weak BR-deficient or BR-insensitive mutant phenotypes, including short and round leaves, prolonged senescence, dwarfed shape, and altered expression levels of the BR-responsive genes. Hypocotyl length and root inhibition assays suggest that the drl1-D mutant responds to BRs normally, but has decreased BR signaling outputs. The endogenous levels of several BRs, including typhasterol (TY), 6-deoxotyphasterol (6-deoxoTY), and 6-deoxocastasterone (6-deoxoCS), are significantly lower in the drl1-D mutant than in the wild-type. The DRL1 gene encodes an acyltransferase and is widely expressed in leaves, roots, flowers, and siliques. Plants without DRL1 and its homologs are larger with an enhanced BR signaling. The expression of DRL1 was induced by eBL and inhibited by ABA. DRL1 is involved in the BR metabolism likely by catalyzing the BR conjugation through esterification, which plays important roles in regulating the BR homeostasis and responding to abiotic stresses in Arabidopsis.
authors.affiliation: State Key Laboratory of Genetic Engineering and Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, PR China.
authors.forename: Wenjiao
authors.initials: W
authors.lastname: Zhu
authors.forename: Haijiao
authors.initials: H
authors.lastname: Wang
authors.forename: Shozo
authors.initials: S
authors.lastname: Fujioka
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.forename: Hailong
authors.initials: H
authors.lastname: Tian
authors.forename: Weisheng
authors.initials: W
authors.lastname: Tian
authors.forename: Xuelu
authors.initials: X
authors.lastname: Wang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006706:Homeostasis / Q000187:drug effects; D009154:Mutation; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; C474637:DRL1 protein, Arabidopsis; D000040:Abscisic Acid; D000217:Acyltransferases; D019204:GTP-Binding Proteins