Abstract: Flavonoids are an important secondary metabolite of plants. Chalcone isomerase(CHI) is a key enzyme in the early stage of flavonoid biosynthesis, which plays an crucial regulatory role in the development and color formation of seed coat.To further study the features and biological function of CHI gene in seed coat development and in seed colour formation. 16 yellow and brown rapeseed of three types as experimental materials. The CHI gene sequence was obtained by homology-based cloning strategy, the open reading frame of CHI was 756 or 759 bp, encoding 251 or 252 amino acids. Furthermore, DNAMAN (v5.0) was used to align the homology sequence.The results showed that the homology of nucleotide sequence was 96.41%; the chalcone superfamily conserved domain was found in these cloned genes using NCBI on-line software CDD; the phylogenetic tree of CHI in many species was constructed by MEGA 5.2. Results showed that compared to Brassica juncea, CHI gene had more closer relationship between Brassica napus and Brassica rapes in three types of rapeseed,besides in Rapes, Radish and Arabidopsis thaliana showed close relationship.By comparing the characteristics of CHI gene sequence between yellow seeded rapeseed and brown seeded rapeseed in three types of rapeseed,there was a difference in nucleotide at position of 202 (C/A),which led to a difference in amino acid (P/T) respectively,as a result,the color of the rape seed coat might change.This study will lay the foundation for clarifying the further study on its action mechanism and function characteristics.

Key words: Rapeseed, Chalcone isomerase, CHI, Cloning, SNP

CLC Number: 

• Q78

• S634.03