Research On Heat Shock Expression Of HSP27 And HSP70 In Eight Insect Pests And Natural Enemies

Heat shock proteins(HSPs)are a group of special proteins with high hereditary conservation that are widely existed in prokaryotes and eukaryotes.HSPs can express strongly under stress conditions.Besides,HSPs also play an important role of possessing molecule chaperones,preventing apoptosis,enhancing thermotolerance in cells,and regulating physiological activities and others important functions in organisms.At present,heat shock proteins are mainly researched in terms of medicine,while there are less papers on heat shock proteins of insect,in which only fruit flies are involved in a deepgoing way.In the article,we provided a study about effects of heat stress on HSP27and HSP70 heat shck expression of cruciferous vegetables insect pests and natural enemies mainly by enzyme-linked immunosorbent assay.By analyzing the change process of HSPs within insects after being treated with different temperature gradients and times,the change in expression of HSPs of insects under heat stress conditions and the variiation law of different insects under the same temperatures were investigated.meanwhile,effects of high-temperature induction on HSP27 and HSP70 of insect with different resistant levels were further studied.And the research results showed that:(1)HSP27 and HSP70 expression quantities in different insects exhibited significant differences(P<0.05)with the change of temperatures,but expression laws of HSP27 and HSP70 were different among insects.(2)HSP27 and HSP70 expression quantities were not completely in positive correlation with temperature within the range of insect lethal temperature,which means that high temperature can not absolutely induce HSP27 and HSP70 expression.(3)The expression of HSP27 and that of HSP70 in insects are independent with each other.By analyzing the heat shock expression of HSP27 and HSP70 in Propylaea japonica,Plutella xylostella,Pieris rapae crucivorawe,Pteromalus puparum,Phyllotreta striolata,Lipaphis erysimi,Phaedon brassicae bally,Chilomenes quadriplagiata,found that the heat shock expression of HSP27 is not necessarily related to that of HSP70,they do not effect each other.(4)By analyzing the heat shock expression of HSP27 and HSP70 in Propylaea japonica,turnip and diamondback moth of strains with different resistances,the result indicated that the sensitive strain of the same insect has a lower HSP27 and HSP70 expression quantity than the resistant strain thereof at room temperature.However,the high-temperature induced expression level of HSP27 and HSP70 of the sensitive strain of the insect is significantly higher than that of the resistant strain thereof(P<0.01)after heat shocks of the same temperature and time,this indicated that the expression of HSP27 and HSP70 in sensitive strain is easier to be induced by high temperature than those in resistant strain.Above all,variations in HSP27 and HSP70 expression of cruciferous vegetable insect pests and natural enemies under heat stress conditions obtained by means of enzyme-linked immunosorbent assay further proved that high temperature can induce the expression of HSP27 and HSP70.HSP27 and HSP70 play an important role in protecting insects when under high temperature stress,but this function is limited.The expression features of HSP27 and HSP70 under heat stress were different among different insects,and there were no necessary connection of heat shock expression between HSP27 and HSP70,the fitness cost of insect resistance under heat stress was explored by studying the heat shock expression of HSP27 and HSP70 in sensitive and resistant strains of insects.These studies enriched the relationship between heat shock and HSPs,and also revealed the sophisticated and diverse expression variation mechanism of HSP27and HSP70 and even the whole HSP family.So far,the mechanism of action of heat shock to HPSs is not clear,which needs extensive research.