AaPGRP-SC2在埃及伊蚊抗Bti杀虫晶体蛋白Cry4Ba和Cry11Aa侵染中的功能OA北大核心

[Objective]The peptidoglycan recognition protein AaPGRP-SC2 of Aedes aegypti was investigated in defending the infec-tion of insecticidal crystal protein Cry4Ba and Cry11A of Bacillus thuringensis subsp.israelensis(Bti),aiming to build foundation for the development of new biopesticide.[Method]After infected by Cry4Ba and Cry11Aa,the expression of AaPGRP-SC2 gene,anti-microbial peptides(AMPs)genes and related genes of Toll and immune deficiency(IMD)pathways in 4th instar larvae of A.aegypti were determined by quantitative real-time PCR(qRT-PCR)at different time.After prokaryotic expression and purification,protein AaPGRP-SC2 was detected by SDS-PAGE and Western blot.The combination of AaPGRP-SC2 with Cry4Ba and Cry11Aa was fur-ther analyzed by Far Western blot technique.[Result]Compared with the control group,the expression of AaPGRP-SC2 in the 4th instar larvae of A.aegypti was significantly increased at 2 h after infected by Cry4Ba and Cry11Aa.At 12 h,the expression of AaPGRP-SC2 continued to increase in the Cry11Aa treatment group,but was decreased in the Cry4Ba treatment group.The expres-sion of 4 AMPs genes(CecA,Att,Dipt and DefA)and 3 downstream genes(Spz2,Tube and Toll1A)in Toll pathway were signifi-cantly increased at 2 h after the infection,and continued to be higher than the control group at 12 h.While in IMD pathway,Ankyrin1 in the Cry11Aa treatment group was the only one which was up-regulated,and the other genes,including Ankyrin2,Ankyrin3,Kenny and UevlA,were not significantly different from the control group at any time.Protein AaPGRP-SC2 was success-fully expressed,and purified insecticidal crystal protein Cry4Ba and Cry11Aa were obtained.Far Western blot further indicated that AaPGRP-SC2 could combine with Cry4Ba and Cry11Aa.[Conclusion]AaPGRP-SC2 could activate the Toll pathway to produce AMPs,but did not significantly advance on the regulation of IMD pathway in activating AMPs genes.