刀孢轮枝菌胞外几丁质酶的基因克隆及系统发育分析

Cloning of the chitinase gene Lpchi1 and phylogenetic analysis of Lecanicillium psalliotae

Nematophagous fungi, one of the natural enemies of nematodes, have been employed in biological control. Extracellular enzymes secreted from nematophagous fungi, including protease, chitinase and collagenase serve as virulence factors of infection. In this study, we found Lecanicillium psalliotae can penetrate the eggs of the root-knot nematode Meloidogyne incognita and influence development of the eggs. A chitinase gene Lpchi1 was isolated from L. psalliotae using degenerate primers and DNA-walking technique. Comparison of the chitinase amino acid sequences from different pathogenic fungi revealed that the enzymes were highly similar. The phylogenetic analysis demonstrated that the chitinases derived from different fungi were clustered into three main clades corresponding to different molecular weight.