Research On Heat Stress Expression Of Bax、Bcl-2 And Caspase-3 In Insecticide-resistant And-susceptible Plutella Xylostella

In recent years,a large number of studies have shown that mitochondrial pathways play an important role in the mechanism of apoptosis.Among them,the Bcl-2 protein family(Bcl-2,Bax)is the upstream regulatory protein of this pathway,whereas CPLaspase-3 is the downstream downstream of the pathways that perform proteases.The relationship between the three in the process of apoptosis has become a hot issue in the study of apoptosis.Plutella xylostella(Diamondback moth,DBM)is a worldwide pest,According to the results of previous studies,the physiological fitness of insecticide-susceptible(S)and-resistant(R)DBM significantly decreased under high temperature stress.In this paper,the effects of different temperature and time on the contents and activities of Bcl-2 and Bax and the content of Caspase-3 in adults and pupaee of DBM were studied.To investigate the effects of heat stress on the expression of Bcl-2,Bax and Caspase-3 in DBM.Research indicates:(1)Under high temperature stress,the expression of Bax protein increased significantly in insecticide-susceptible(S)and-resistant(R)DBM.The increased expression of the resistant DBM was higher than that of the susceptible DBM,there was no similarity between the increase of Bax expression in insecticide-susceptible(S)and-resistant(R)DBM pupae.(2)The activity of Bax protein in insecticide-susceptible(S)and-resistant(R)DBM was significantly increased under high temperature stress,and the uptake of Bax protein activity in adults and pupae was significantly higher than that in susceptible DBM.(3)Under high temperature stress,the expression of Bcl-2 protein was significantly decreased in insecticide-susceptible(S)and-resistant(R)DBM.The expression of Bcl-2 protein in resistant DBM pupae was significantly higher than that in insecticide-susceptible pupae,but there was no similarity between insecticide-susceptible(S)and-resistant(R)DBM adults.(4)After high temperature treatment,resistance and sensitive DBM adults and pupae Bcl-2 activity both decreased under high temperature stress,and there was no significant difference in the activity reduction between insecticide-susceptible and-resistant DBM.(5)The expression of Caspase-3 in insecticide-susceptible(S)and-resistant(R)DBM was significantly increased under high temperature stress,and resistant DBM was more likely to be induced than insecticide-susceptible DBM.Therefore,it is concluded that:(1)High temperature stress can induce the expression and activity of Bax protein and the upregulation of Caspase-3 protein expression,and down-regulation of Bcl-2 protein expression and activity in DBM;.(2)The expression of Caspase-3 protein in resistant DBM was significantly higher than that in insecticide-susceptible DBM after high temperature stress.Bax and Bcl-2 protein as the upstream regulatory mechanism of Caspase-3 enzyme protein,by regulating Caspase-3 to control apoptosis,indicating that high temperature can significantly inhibit the physiological fitness of DBM,but the inhibition of resistant DBM was more significant.