亚洲玉米螟幼虫体内抗菌肽的诱导

Inducement of antibacterial peptide from Ostrinia furnacalis Guenée larvae

外源物侵染可引起亚洲玉米螟幼虫产生免疫应激反应,并诱导产生抗菌肽。为深入研究抗菌肽作用机制,作者给亚洲玉米螟5龄幼虫注射大肠杆菌,诱导其产生抗菌肽,并分析该抗菌肽的部分性质。结果表明:亚洲玉米螟幼虫注射3.0×106个/mL大肠杆菌后可诱导其体内产生一种相对分子量为12.1kD的抗菌肽,在12～36h内该抗菌肽的诱导表达量与时间成正比。此抗菌肽对大肠杆菌和金黄色葡萄球菌都有一定的抑制作用,100℃高温处理5min后具有明显的抑菌活性,pH为8.0时抑菌活性最强,抑菌圈直径达6.9±0.3mm,且具有一定的温度稳定性和酸碱稳定性。

The invasion of exogenous material may cause immunological and stress response in Ostrinia furnacalis Guenre larvae, and the antibacterial peptide （AP） could be induced. In order to further investigate the mechanism of AP, in this study, the pathogen of Escherichia coli was injected into 5th instar O. furnacalis larvae, and a novel type of antibacterial peptide was produced. The results showed that the antibacterial peptide with the relative molecular weight of 12.1 kD was induced when the larvae was injected with E. coli cell at the concentration of 3.0 × 106 cell/mL. The expression of this antibacterial peptide in- creased with the inducing time from 12 -36 h. Both E. coli and Staphylococcus aureus could be inhibited by the antibacterial peptide. There was significant antibacterial activity when the antibacterial peptide was treated at 100 ℃ for 5 min. The activity of the antibacterial peptide was the highest at the pH value of 8.0, and the diameter of inhibition zones was 6.9 ± 0.3 mm. This kind of antibacterial peptide has some heat, acidic and basic stability.