Abstract
To identify useful genes from rice, we constructed and analyzed Arabidopsis overexpressing rice full-length cDNAs. Among them, we isolated a transgenic plant (#R10933) with yellow seeds. In aerial part of R10933, the levels of flavonoids including cyanidin, kaempferol, and quercetin derivatives were lower than in wild type. Traits of reduced anthocyanin were genetically dominant. Expression of genes involved in anthocyanin synthesis was not suppressed.
A F-box gene with Kelch repeats was identified in R10933. Introduction of this gene caused repression of anthocyanin level in Arabidopsis and tomato. The F-box protein interacted with chalcone synthase (CHS) protein in yeast two-hybrid system. Transcriptional level of Arabidopsis homologue increased transiently soon after transfer from high-light stress condition to normal condition. These results indicate that the F-box protein plays a role of CHS degradation during rapid suppression of anthocyanin synthesis.
