RRC ID 4009
著者 Matsui K, Umemura Y, Ohme-Takagi M.
タイトル AtMYBL2, a protein with a single MYB domain, acts as a negative regulator of anthocyanin biosynthesis in Arabidopsis.
ジャーナル Plant J
Abstract SUMMARY:In Arabidopsis, MYB transcription factors regulate flavonoid biosynthesis via the formation of protein complexes with a basic helix-loop-helix (bHLH) transcription factor and a WD40 repeat protein. Several R3-type single-MYB proteins (R3-MYB), such as CPC and TRY, act as negative regulators of the development of epidermal cells. However, such regulators of flavonoid biosynthesis have not yet been reported, to our knowledge. We show here that an R3-MYB protein, AtMYBL2, acts as a transcriptional repressor and negatively regulates the biosynthesis of anthocyanin in Arabidopsis. In an AtMYBL2 knockout line (mybl2), the expression of the DFR and TT8 genes was enhanced and resulted in the ectopic accumulation of anthocyanin, while ectopic expression of AtMYBL2 or of a chimeric repressor that is a dominant negative form of AtMYBL2 suppressed the expression of DFR and TT8, and the biosynthesis of anthocyanin. The expression of AtMYBL2 was detected in various tissues but not in those in which anthocyanin accumulated or TT8 was expressed. The minimal repression domain of AtMYBL2 was found to be the six amino acids (TLLLFR) at the carboxyl terminus, and TLLLFR appears to be a novel repression motif that is different from the ERF-associated amphiphilic repression (EAR) motif. The defective phenotype of mybl2 mutants was complemented by 35S:AtMYBL2 but enhanced by a truncated form of AtMYBL2 from which the repression domain had been deleted. AtMYBL2 bound directly to TT8 protein and this complex suppressed the expression of DFR and TT8. The repression activity of AtMYBL2 appears to play a critical role in the regulation of anthocyanin biosynthesis.
巻・号 55(6)
ページ 954-67
公開日 2008-9-1
DOI 10.1111/j.1365-313X.2008.03565.x
PII TPJ3565
PMID 18532977
MeSH Alcohol Oxidoreductases / metabolism Anthocyanins / biosynthesis* Arabidopsis / genetics* Arabidopsis / metabolism Arabidopsis Proteins / genetics Arabidopsis Proteins / metabolism* Basic Helix-Loop-Helix Transcription Factors / metabolism DNA-Binding Proteins / genetics DNA-Binding Proteins / metabolism* Gene Expression Regulation, Plant Genes, Plant RNA, Plant / genetics Repressor Proteins / genetics Repressor Proteins / metabolism* Reverse Transcriptase Polymerase Chain Reaction Seeds / genetics Seeds / metabolism Transcription Factors / genetics Transcription Factors / metabolism* Transcription, Genetic Transformation, Genetic Two-Hybrid System Techniques
IF 6.141
引用数 299
WOS 分野 PLANT SCIENCES
リソース情報
シロイヌナズナ / 植物培養細胞・遺伝子 pda02641