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| Entry URI | http://metadb.riken.jp/db/SciNetS_ria224i/cria224u4ria224u17314094i |
| Entry name | Yonekura-Sakakibara Keiko et al. 2007 May. J. Biol. Chem. 282(20):14932-41. |
| Title | Identification of a flavonol 7-O-rhamnosyltransferase gene determining flavonoid pattern in Arabidopsis by transcriptome coexpression analysis and reverse genetics. |
| Authors | Niida Rie|Saito Kazuki|Tohge Takayuki|Yonekura-Sakakibara Keiko |
| Abstract | Glycosylation plays a major role in the remarkable chemical diversity of flavonoids in plants including Arabidopsis thaliana. The wide diversity encoded by the large family-1 glycosyltransferase (UGT) gene family makes it difficult to determine the biochemical function of each gene solely from its primary sequence. Here we used transcriptome coexpression analysis combined with a reverse genetics approach to identify a gene that is prominent in determining the flavonoid composition of Arabidopsis. Using transcriptome coexpression analysis accessible on the ATTED-II public data base, the expression pattern of a UGT gene, UGT89C1, was found to be highly correlated with known flavonoid biosynthetic genes. No C-7 rhamnosylated flavonols were detected in either of two T-DNA ugt89c1 mutants. This specific metabolite deficiency in the mutants was complemented by stable transformation with the genomic fragment containing intact UGT89C1. Glutathione S-transferasefused recombinant UGT89C1 protein converted kaempferol 3-O-glucoside to kaempferol 3-O-glucoside-7-O-rhamnoside and recognized 3-O-glycosylated flavonols and UDP-rhamnose as substrates, but not flavonol aglycones, 3-O-glycosylated anthocyanins or other UDP-sugars. These results show that UGT89C1 is a flavonol 7-O-rhamnosyltransferase. The abundance of UGT89C1 transcripts in floral buds was consistent with the flavonoid accumulation of C-7 rhamnosylated flavonols in Arabidopsis organs. Our present study demonstrates that the integration of transcriptome coexpression analysis with a reverse genetic approach is a versatile tool for understanding a multigene family of a metabolic pathway in Arabidopsis. |
| Pubmed ID | 17314094 |
| Journal | The Journal of biological chemistry |
| Volume | 282 |
| Issue | 20 |
| Pages | 14932-41 |
| Publication date | 2007 May |
| Num of phenotype gene | 0 |