Chalcone isomerase (CHI) is the key enzyme that catalyzes chalcone into (2S)-flavanol or (2S)-5-desoxidation flavanol. The full length cDNA (1050 bp) of AhCHI
( Arachis hypogaea
CHI gene) was cloned by large scale EST sequencing using a peanut immature seed cDNA library. Sequence analysis results indicated that it was a type I CHI gene (with the accession number JN660794). The ORF of AhCHI
was 768 bp, encoding a peptide of 255 amino acids with a pI of 5.189. Sequence alignment showed that the coding region of AhCHI
gene is highly conserved to compare with CHI genes from other plant species. Peanut cDNA microarray and semi-quantitative RT-PCR analysis indicated that AhCHI
was highly expressed in pegs. The expression level in flower and root was higher than the expression level in stem and leaf. AhCHI
was expressed in a high level in seeds with a purple seed coat, while its expression was low in seed with white seed coat.