Abstract:

Chalcone synthase (Chs) and chalcone isomerase (Chi) are two key enzymes in the biosynthesis pathway of plant
flavonoids. The complete genes of chs and chi were isolated from Olea europaea by homology cloning, RT-PCR, FPNI-PCR
(fusion primer and nested integrated PCR) and 3’-RACE (rapid amplification of cDNA end). Sequence analysis showed that
the full-length DNA (GenBank No: KF935223.1) and cDNA (GenBank No: KF935224.1) of chs gene from O. europaea
were 2 085 bp and 1 173 bp, respectively, and the ORF (open reading frame) of chs gene encoded 390 amino acid residues,
which showed high similarity (about 90%) with the complete amino acid sequences of Chs from Vitis vinifera and Solanum
lycopersicum. Bioinformatics analysis showed that the protein encoded by chs gene from O. europaea belonged to the Chs
protein family. The full-length DNA (GenBank No: KF886190) and cDNA (GenBank No: KF886191) of chi gene from
O. europaea were 1 373 bp and 750 bp, respectively, and the ORF of chi gene encoded 249 amino acids residues. With the
highest similarity (about 65%) to the complete amino acid sequences of Chi from the other plants , the full-length amino acid
sequence of Chi from O. europaea had an intramolecular lyase domain with 198 amino acids, which was consistent with the
characteristics of the Chi protein family.

Key words: Olea europaea, chalcone synthase (Chs), chalcone isomerase (Chi), gene cloning, sequence analysis