Genome-wide identification of the main antibacterial factor-antibacterial peptides
Author of the article:LIU Xiao-Yu1** LIU Jia-Yi1 TANG Yan2 WU Mei-Man1 DAI Xiao-Yan3 MENG E2*** ZHAI Yi-Fan3***
Author's Workplace：1. Belgorod Institute of Food Sciences, Dezhou University, Dezhou 253023, China; 2. College of Ecology, Resources and Environment, Dezhou University, Dezhou 253023, China; 3. Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China
Key Words：temperature stress; Escherichia coli; Staphyoccus aureus; antibacterial peptides; gene family
Abstract：[Aim] To investigate the effect of temperature on the immune system of the spotted-wing drosophila, Drosophila suzukii, a globally significant agricultural pest, and also determine the composition, structure and evolutionary characteristics, of the antimicrobial peptides (AMPs) of this species. [Methods] The antibacterial activity of different developmental stages of D. suzukii reared at 14, 18 and 22 ℃ against Escherichia coli and Staphyoccus aureus was determined using the turbidimetric method, and the composition, structure and evolutionary relationship of its AMPs were analyzed using bioinformatics. Transcriptional levels of AMPs at different temperatures were measured with quantitative PCR. [Results] The lowest antibacterial activity of eggs against E. coli (P < 0.01) and S. aureus (P < 0.001) was measured at 18 ℃, and that of larvae against E. coli (P < 0.01) and S. aureus (P < 0.05) at 22 ℃. There was no significant difference in pupal antibacterial activity against E. coli (P = 0.351) or S. aureus (P = 0.058) among the tested temperatures. D. suzukii has 21 AMPs belonging to 3 groups, including 5 Attacins, 5 Cecropins, 7 Drosomycins, 2 Diptericins, 1 Defensin and 1 Metchnikowin. The Drosomycins and Defensin have a close phylogenetic relationship to those of D. melanogaster, whereas the other AMPs were species-specific. Expression of Diptericin A transcripts of larvae at 22 ℃ was significantly higher than at 14 and 18 ℃ (P < 0.05). [Conclusion] Stronger antibacterial activity in early spring may reduce the effectiveness of biocontrol methods for D. suzukii. Most AMPs of this species are species-specific, and their response to temperature varied.