Overexpression of CHS genes from Trifolium repens increases tobacco flavonoid content

To explore the effect of chalcone synthase on the flavonoid content in Trifolium repens, the full-length cDNA fragment named chalcone synthase (TrCHS) gene in Trifolium repens was obtained by RT-PCR cloning, using the sequence of TrCHS (GenBank: No.2247906) provided by NCBI. The expression vector containing TrCHS was successfully constructed in tobacco and the transgenic tobacco lines were obtained and the flavonoid content was determined by resistance screening and molecular detection. The results showed that the expression of TrCHS and flavonoids in the transgenic tobacco were significantly increased compared to the wild type (P < 0.05), indicating that over-expression of TrCHS increased the flavonoids content in tobacco. Thus, our results provide a theoretical basis for exploring the function of TrCHS and for breeding new varieties of Trifolium repens.