title: BZR1 and BES1 participate in regulation of glucosinolate biosynthesis by brassinosteroids in Arabidopsis.
abstract: The effect of 24-epibrassinolide (EBR) on glucosinolate biosynthesis in Arabidopsis thaliana was investigated in the present study by using mutants and transgenic plants involved in brassinosteroid (BR) biosynthesis and signal transduction, as well as glucosinolate biosynthesis. The results showed that EBR significantly decreased the contents of major aliphatic glucosinolates including glucoiberin (S3), glucoraphanin (S4), and glucoerucin (T4), as well as the indolic glucosinolates glucobrassicin (IM) and neoglucobrassicin (1IM). In addition, a significantly higher level of glucosinolates accumulated in the BR-deficient mutant cpd and a dramatically lower glucosinolate content in the transgenic plant DWF4-ox overexpressing the BR biosynthetic gene DWF4 compared with their related wild-types, confirmed the repressing effect of BR on glucosinolate biosynthesis. BRI1, the receptor of BR signal transduction, was involved in regulation of glucosinolate biosynthesis by BR. Furthermore, the observation of reduced content of glucosinolates and lower expression levels of glucosinolate biosynthetic genes in 35S-BZR1/bzr1-1D and bes1-D plants compared with the corresponding wild-types suggested that BZR1 and BES1, two important components in BR signal transduction, are responsible for the inhibiting role of BR in glucosinolate biosynthesis. The disappearance of the repressing effect of BR on glucosinolate content in the myb28, myb34, and myb122 mutants indicated that these three MYB factors are important for the regulation of BR in glucosinolate biosynthesis.
authors.affiliation: Key Laboratory of Horticultural Plant Growth, Development and Quality improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Rongfang
authors.initials: R
authors.lastname: Guo
authors.forename: Hongmei
authors.initials: H
authors.lastname: Qian
authors.forename: Wangshu
authors.initials: W
authors.lastname: Shen
authors.forename: Lihong
authors.initials: L
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Congxi
authors.initials: C
authors.lastname: Cai
authors.forename: Yanting
authors.initials: Y
authors.lastname: Zhao
authors.forename: Junjie
authors.initials: J
authors.lastname: Qiao
authors.forename: Qiaomei
authors.initials: Q
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000378:metabolism / Q000502:physiology*; D060406:Brassinosteroids / Q000378:metabolism* / Q000494:pharmacology; D004268:DNA-Binding Proteins; D005961:Glucosinolates / Q000096:biosynthesis*; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D013260:Steroids, Heterocyclic / Q000494:pharmacology
chemical_list: D029681:Arabidopsis Proteins; C456160:BES1 protein, Arabidopsis; C454444:BZR1 protein, Arabidopsis; D060406:Brassinosteroids; D004268:DNA-Binding Proteins; D005961:Glucosinolates; D009687:Nuclear Proteins; D013260:Steroids, Heterocyclic; C023623:brassinolide
keywords: Arabidopsis thaliana; BES1; BZR1; MYB.; brassinosteroids; glucosinolates