Abstract: The reported chalcone isomerase genes were downloaded from database online,and the degenerate primers were designed.The full length of safflower chalcone isomerase genes was cloned by RACE,named as CtCHI1 and CtCHI2,and NCBI accession numbers were MF996507 and MF996508,respectively.The sequence was analyzed by software online and the evolutionary tree was constructed by MEGA.Sequence analysis showed that CtCHI1 was 967 bp and CtCHI1,2 was 997 bp,and belonged to chalcone isomerase family.The expression pattern of chalcone isomerase gene was analyzed by quantitative RT-PCR.Expression analysis showed that CtCHI1 was mainly expressed in flower with highly expression in the second developmental stages of flower,not expressed in leaves,stems and roots, CtCHI2 was mainly expressed in stem.At the same time,it was found that MeJA could significantly promote the expression of CtCHI1,but had no effect on the expression of CtCHI2.Two chalcone isomerase genes CtCHI1 and CtCHI2 were successfully cloned by RACE,and it was proposed that CtCHI1 was involved in the biosynthesis of flavonoids in safflower.

Key words: safflower, chalcone isomerase gene, RACE, expression analysis, flavonoids