Studies On The Immune Response Of Oxya Chinensis

Insect hemocytes are the first line of defense for its immune defense.In recent years,there have been few studies on the immunity of insect henocytes,especially on Oxya chinensis.Studying the immune response of insect hemocytes can not only provide ideas for the study of more effective and safer pest control methods,but also provide a theoretical basis for the study of insect immunity.In this article,the hemocytes of Oxya chinensis were infected with particulate matter(C powder,Fe powder and Si powder),bacteria(Escherichia coli,Bacillus subtilis and Staphylococcus aureus)and pesticides(cypermethrin,Azadirachtin and avermectin).Wright-Giemsa method was used to observe the morphological and quantitative changes of hemocytes of Oxya chinensis,and to analyze the types of cells involved in immunization in hemocytes.The humoral immunity of Oxya chinensis hemocytes was evaluated by measuring the activities of antioxidant enzymes,metabolic enzymes and phenoloxidases in hemocytes of different time periods.By observing the hemocytes smear,it was found that apoptosis,nucleus deformation,vacuolation,granulocyte degranulation and cell shrinkage occurred in the hemocytes after infection with exogenous substances.In addition,after infection with particulate matter and bacteria,phagocytosis of plasma cells,nodules and cysts of plasma cells and granulocytes were found,and cellular immune processes of adsorption,phagocytosis and digestion of bacteria were found.By counting the number of different types of cells in hemocytes smears at different times,it was found that the number of plasmatocytes,granulocytes and cysts in hemocytes changed most obviously,the number of plasmatocytes increased first and then decreased;the number of granulocytes decreased first and then increased;the number of cysts continued to increase.The activity of SOD and POD in hemocytes were obvirously higher than those in control group at different time points(P<0.05);the higher the concentration of pesticides,the higher the activity of SOD and POD,and they were obvirously higher than the blank control group(P<0.05).PO activity of Si powder in particulate matter group was obvirously higher than that of blank control group at 8 h-48 h(P<0.01),PO activity of C powder group and Fe powder group at 24 h-48 h was significantly higher than that of blank control group(P<0.01),PO activity of three bacteria in bacterial species group at 12 h was significantly higher than that of blank control group(P<0.01).PO activity in Azadirachtin group was significantly higher than that in blank control group at 10 h and 24 h(P<0.01),in which 120 ug/L PO activity was the highest;in avermectin group,PO activity was significantly higher than that in blank control group at 10 h(P<0.05),of which 80 ug/L PO activity was the highest;in cypermethrin group,PO activity was significantly higher than that in blank control group at 6 h(P<0.01),of which 40 ug/L PO activity was the highest.The activities of CES and P450 in the particulate matter group were significantly higher than those in the blank control group(P<0.01);the activities of CES in the bacterial strain group were significantly higher than those in the blank control group(P<0.01)from 8 h to 48 h;and the activities of P450 in the 24 h to 48 h were obvirously higher than those in the blank control group(P<0.01).The activity of P450 in Azadirachtin group was significantly higher than that in blank control group at 6 h-24 h(P<0.01).The activity of 120 ug/L was the most obvious change,but the activity of CES had no significant difference(P>0.05).The activity of P450 in avermectin group at 24 h was obvirously higher than that in blank control group(P<0.01),and the activity of CES at 10 h and 24 h was significantly higher than that in blank control group(P<0.01).The activity of P450 and CES at 80 ug/L changed the most.The activity of P450 in cypermethrin group was obviously higher than that in blank control group at 6 h(P<0.05),and the activity of CES was obvirously higher in 2 h-24 h than that in blank control group(P<0.05),and the activity of P450 and CES at 40 ug/L changed the most.