【摘要】 【目的】明确柞蚕Antheraea pernyi对外源微生物防御性生理变化规律,为柞蚕的病害防治和合理饲养提供理论依据。【方法】本研究选用革兰氏阳性菌苏云金芽孢杆菌Bacillus thuringeinsis(Bt)和革兰氏阴性菌大肠杆菌Escherichia coli(Ec)为外源诱导微生物,调整至10~6～10~8cfu/m L菌液,灭活后处理柞蚕蛹,诱导24,48,72和96 h后不同时间测定血淋巴蛋白含量、PO活性、CAT活性、抗菌活性和溶菌酶活性等生理指标。【结果】Ec和Bt诱导柞蚕蛹导致各生理指标出现显著变化,但两种菌株诱导生理指标变化规律差异明显,Ec高浓度诱导72 h会增加血淋巴蛋白含量,而Bt各浓度诱导会在24,48和96 h增加血淋巴蛋白含量。免疫防御关键酶系PO和CAT活性变化规律在不同菌株诱导后差异更明显,Ec诱导后,PO活性随着时间增加表现为先升高后降低的趋势,CAT活性呈现"升高-降低-升高"的规律;而Bt诱导后PO活性表现为"升高-降低-升高"的规律,CAT活性随诱导时间增加变化规律不明显,但有随菌液浓度增加而降低的趋势。对抗菌活性测定表明,Ec和Bt诱导都会显著增加蛹粗酶液抗菌活性,溶菌酶活性也会极显著增加,但2个指标高峰值出现的时间会有明显差别。【结论】本研究结果表明Ec和Bt不同处理均可诱导柞蚕蛹产生明显防御反应,但柞蚕蛹生理指标变化规律与不同种类微生物及处理时间和浓度有关,推测革兰氏阳性菌和革兰氏阴性菌具有不同的诱导防御反应机制。研究结果可以为外源微生物侵染柞蚕后的免疫防御反应规律提供理论指导。更多还原

【Abstract】 【Aim】This study aims to investigate the defensive responses in the Chinese tussah moth,Antheraea pernyi induced by different exogenous microbes so as to obtain measures for the disease control and breeding of the moth. 【Methods】Gram-positive bacteria Bacillus thuringeinsis( Bt) and gram-negative bacteria Escherichia coli( Ec) were selected as the exogenous microorganisms. The concentration of the bacterial solution was adjusted to 10~6- 10~8 cfu / m L. A. pernyi pupae were induced by inactivated bacteria for 24,48,72 and 96 h,and the physiological indices including hemolymph protein content and the PO activity,CAT activity, antibacterial activity and lysozyme activity in hemolymph were analyzed.【Results】Ec and Bt induced prominent changes in several physiological indices of A. pernyi pupae. But the patterns of physiological indices induced by the two bacteria were distinctly different. Haemolymph protein content in A. pernyi pupae increased at 72 h after induction by high concentrations of Ec,while it increased at 24,48 and 96 h after induction by Bt at various concentrations. The activities of immune defense key enzymes including PO and CAT changed remarkably. The PO activities increased first and then decreased,while the CAT activities showed an increase-decrease-increase tendency after induction by Ec. The PO activities showed an increase-decrease-increase fluctuating pattern,while the CAT activities had no obvious alteration after induction by Bt. Antibacterial activity assay showed that Ec and Bt induced a significant increase in antibacterial activity and lysozyme activity in crude extracts of pupae.But the peak time of antibacterial activity and lysozyme activity was distinctly different. 【Conclusion】The research results indicated that different treatments of Ec and Bt can induce distinct defense responses in A. pernyi pupae,and the variation patterns of physiological indices are related to different kinds of microorganisms and treatment time and concentration. It is speculated that gram positive bacteria and gram negative bacteria have different induced defense mechanisms. We propose that the several physiological indices can be used as markers for immune defense response to exogenous microbes in A.pernyi.更多还原