Cloning,Expression and Function Analysis of Cathepsin Gene Encoded by Spodoptera exigua Nucleopolyhedrovirus Cloning,Expression and Function Analysis of Cathepsin Gene Encoded by Spodoptera exigua Nucleopolyhedrovirus
Abstract: A putative v-cathepsin(v-cath) gene of Spodoptera exigua nucleopolyhedrovirus(SeMNPV) was cloned,sequenced and expressed.The results showed that the gene size was 1014 nucleotides,encoding a 338 amino acids putative protein.The amino acid sequence alignment of ten baculoviral v-CATHs showed that the primary structure and the catalytic sites were conserved.A pholygenetic tree of these v-CATHs constructed by using maximum parsimony analysis indicated that the v-cath gene of SeMNPV had a different evolutionary history from that of other NPVs.When late 3th instar Spodoptera exigua larvae were infected with SeMNPV combinded with 1.2 μL expressed bacteria and medium,the mortality was increased 9.21%,and LT50 was 12 h shorter than the control.The v-CATH expressed in prokaryote has a significant effect on the killing speed of SeMNPV insecticide.