Abstract: To verify the function of chalcone reductase gene (CHR1) in soybean Daidzein synthesis, CHR1 gene in soybean was cloned, and an RNAi expression vector pCPB-CHR1-RNAi was constructed. Four transformed plants in T₀ generation and thirteen transformed plants in T₁ generation of soybean “Jinong28” were obtained by agrobacterium-mediated genetic transformation, in which transcriptions of CHR1 gene were depressed. Southern blotting showed the functional fragment of pCPB-CHR1-RNAi was integrated into the genome of recipient soybean in the form of a single copy. Detection of the transcription of CHR1 gene using quantitative real-time PCR (qRT-PCR) showed that the expression of CHR1 gene in transformed plants decreased 60%-99% compared to the recipient soybean, while the content of isoliquiritigenin, the precursors of daidzein, decreased 38.7%. These results indicate that RNA interference can suppress the transcription of CHR1 gene expression successfully.

Key words: soybean, chalcone reductase CHR1, daidzein, RNA interference vector