球孢白僵菌对亚洲玉米螟血细胞毒力和形态的影响

Effects of Beauveria bassiana on virulence and cellular morphology of hemocytes of Ostrinia furnacalis

【目的】测定球孢白僵菌Beauveria bassiana对亚洲玉米螟Ostrinia furnacalis血细胞系SYSU-Of He-C的影响,为促进球孢白僵菌在防治亚洲玉米螟中的应用提供理论依据。【方法】采用MTT和CCK-8法测定球孢白僵菌对亚洲玉米螟血细胞系SYSU-Of He-C的毒力,通过光学显微镜与扫描电镜观察球孢白僵菌生长及其对SYSU-Of He-C细胞的影响。【结果】球孢白僵菌分生孢子处理SYSU-Of He-C细胞24 h后,MTT法的IC_(50)值为2.8×10~5mL^(-1),CCK-8法的IC_(50)值为1.4×10~5mL^(-1)。光学显微镜实时监测发现,在SYSU-Of He-C细胞对数期接种球孢白僵菌浓度为3.5×10~4mL^(-1)时,球孢白僵菌具有明显竞争力,未发现囊胞化与吞噬等细胞免疫现象;处理10 h后,球孢白僵菌分生孢子开始萌发长出菌丝,而SYSU-Of He-C细胞减少且开始变形;处理24 h,球孢白僵菌几乎长满整个视野;SYSU-OfHe-C细胞从近似圆形变长或者变为不规则形状,出现聚集、破碎、胞内空泡、瘤状突起,以及被白僵菌菌丝穿透等现象。【结论】球孢白僵菌可改变亚洲玉米螟血细胞系SYSU-Of He-C的细胞形态,但不能使其发生细胞免疫现象。

【Objective】To test the effect of Beauveria bassiana on SYSU-Of He-C,a cell line from hemocytes of Ostrinia furnacalis. To provide a theory basis for application of B. bassiana in the prevention and treatment of O. furnacalis.【Method】MTT and CCK-8 were employed to test the virulence of B. bassiana on SYSU-Of He-C. Optical microscope and scanning electron microscope were used to observe the growth of B. bassiana and its influence on the morphology of SYSU-Of He-C cells. 【Result】The IC_(50) values of B. bassiana against SYSU-Of He-C cells at 24 hours after treatment were recorded as 2. 8 × 10~5 and 1. 4 ×10~5mL^(- 1)respectively by MTT and CCK-8. Furthermore,under real-time monitoring with optical microscope,encapsulization and phagocytosis were not found and B. bassiana was highly competitive when the conidia of B. bassiana were inoculated in the culture of SYSU-Of He-C cells at logarithmic stage reaching a final concentration of 3. 5 × 10~4 mL^(- 1) for B. bassiana. B. bassiana started to germinate at 10 hours after treatment,and meanwhile,SYSU-Of He-C cells started to reduce in number and change in morphology. At 24 hours after treatment,B. bassiana grew the entire visual field. The nearly round SYSU-Of He-C cellshad elongated or turned into irregular shape. Aggregation,fragmentation,cavitation,protuberance and penetration of SYSU-Of He-C cells caused by B. bassiana mycelia were observed.【Conclusion】B. bassiana can change cellular morphology of hemocytes of O. furnacalis,but cannot induce its immune responses.