Cloning and Functional Characterization of a Novel beta-GRP Gene From Melanotus cribricollis

In this study, a novel beta-1,3-glucan recognition protein gene (beta-GRP) was identified from Melanotus cribricollis, and its potential role in the immune response was investigated. The full length of beta-GRP cDNA (Accession Number: MT941530) was 1644 bp, encoding a protein composed of 428 amino acids.The theoretical molecular weight and the isoelectric point were 51.53 kDa and 6.17, respectively.The amino acid sequence of beta-GRP from M. cribricollis was closely related to that of beta-GRP-like from Photinus pyralis, and was predicted to contain conserved GH16 domain without glucanase active site. The results of real-time quantitative PCR showed that fungal infection of Metarhizium pingshaense may significantly upregulated the expression level of beta-GRP gene. The RNAi suppression of beta-GRP gene expression significantly increased the corrected cumulative mortality. Meanwhile, antimicrobial peptide genes defensin and lysozyme were significantly downregulated after interference of beta-GRR.Taken together, these results suggest that beta-GRP of M. cribricollis probably participates in the host immune system by mediating the expression of antimicrobial peptides. This study provides comprehensive insights into the innate immune system of insect larvae. [GRAPHICS] .