葱蝇成虫防御类酶和血细胞对球孢白僵菌的防御作用

测定了葱蝇成虫被球孢白僵菌侵染后,虫体超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、谷胱甘肽-S-转移酶(GSTs)、羧酸酯酶(CarE)和乙酰胆碱酯酶(AChE)的活性变化,并对侵染后血细胞的变化进行拍照观察。结果表明,虫体内SOD、CAT、POD、GSTs和AChE的比活力呈先上升后下降的趋势;处理组虫体内的Car E比活力和对照组的变化趋势相同,但始终低于对照组。侵染36~48 h后,大量的血细胞在菌丝体周围集结、包囊,阻碍和抑制菌丝的增殖。侵染54 h后,菌丝开始突破包囊块,在血淋巴中大量增殖,血细胞免疫被破坏。综上所述,球孢白僵菌侵染初期会触发葱蝇成虫的免疫系统,但由于菌丝的大量增殖,后期免疫系统崩溃,导致成虫死亡。为揭示球孢白僵菌的致病机理及葱蝇对真菌侵染的免疫防御提供理论依据。

Effect of Beauveria bassiana on the Activity of Defense Enzymes and Cellular Defense Response of Adult of Delia antiqua (Meigen)

The changes of the activities of some protection enzymes (SOD,POD,CAT),detoxification enzymes (GSTs,CarE) and AChE of Delia antiqua adult infected by Beauveria bassiana at different stages were determined and the changes of hemocyte after infected were recorded by taking a photograph.The results indicated that the activities of some defense enzymes changes differently after infected by B.bassiana.The activities of SOD,CAT,POD,GSTs and AChE increased firstly,then decreased.The activities of CarE had almost the same changes as those of control.The activities of CarE were lower than the control always.Mass hemocytes were gathered around the mycelium.Nucleation and encapsulation were occurred to impede and inhibit the proliferation of mycelium after infected 36-48 h.After infection 54 h,mycelium began to break through the encapsulation block,proliferate in haemolymph,blood cell immune responses were destroyed.The study concluded that the infection of B.bassiana will trigger the immune system ofD.antiqua adult.Immune system was collapsed due to the large proliferation of B.bassiana,leading the adults to dead.The results may provide reference for learning the pathogenesis ofB.bassiana and the D.antiqua immune defense against B.bassiana.