Abstract：Chalcone synthase (CHS) is a pivot for the biosynthesis of flavonoid antimicrobial phytoalexins and anthocyanin pigments in plants. To clone CHS gene from Conyza blinii Lévl. and analyze its expression in different tissues during florescence, the full- length DNA cloned by RACE was 2 098 bp, including 2 introns (486 and 415 bp); the coding region of cDNA consisted of 1 692 nucleotides, and predicted to code a protein of 399 amino acids which included all the active sites of CHS, named CbCHS (GenBank accession No. KJ155749). Bioinformatic analysis result showed that CbCHS amino acid sequence had a high homology with other opened CHS genes in plants (the highest value of 95%). The RT-PCR result showed that CbCHS was highly expressed in stems (87.03%) and leaves (98.33%) , showed no significant difference between them (P＞0.05), while roots had the lowest expression (9.43%), and showed a significant difference with other tissues (P＜0.05). The anthocyanin content was the highest in stems and leaves, and the lowest in roots, which indicated that there was some relevance between the CbCHS expression and anthocyanins accumulation. The DNA and cDNA sequence of CbCHS gene were firstly obtained from Conyza blinii Lévl. with the research of relationship between the anthocyanin content and gene espression in different tissues of Conyza blinii Lévl.. The results of this study provide some technology basis for the key enzyme expression and regulation mechanism analysis in effective components biosynthesis pathway of Conyza blinii Lévl..
