Full-length cDNA clone and sequence analysis of the chitinase family gene from pear.

In order to get the chitinase gene from pear, specific primers were designed based on the conserved sequence of the plant chitinase gene. Five different cDNA fragments of chitinase genes were amplified by RT-PCR from pear(Pyrus hybrid cv. Huangguan). The full-length cDNAs of Huangguan chitinase genes were produced by using RACE, and named PyChi1, PyChi2, PyChi3, PyChi4 and PyChi5 (GenBank accession No.:FJ589783, FJ589784, FJ589785, FJ589786 and FJ589787), respectively. The results showed that the PyChi1~5 were all full-length cDNA sequence including the complete open reading frame (ORF) and the structure Poly (A), and had higher identities with other plant chitinase gene. Among the five chitnase genes,the nucleic acid sequence identity was 35%~53%, PyChi1 and PyChi4 had the highest amino acid sequence identity,which was 85%, while PyChi1 and PyChi5 produced the lowest amino acid sequence identity, which was 49%. The five chitinaes belong to chitinase ClassesⅠ~Ⅴ in the classification of chitinase family, respectively. Using the bioinformatics analysis, the five types of chitinase had obviously different in sequence of nucleic acid and amino acid, especially about the characteristics of peptide and chitnnase gene structure. These results are helpful for further studies on structure and function of pear chitinase.