Effects Of Graphene Oxide On Growth And Development Of Asian Corn Borer And Its Synergistic Effect On Insecticides

In recent years,the most actively explored and promising application of graphene oxide(GO)as a synergist is to enhance the therapeutic effects of anticancer agents.However,GO as a synergist of pesticides has rarely been reported in the field of plant protection.In this work,the synergistic activity and mode of GO for insecticides against an lepidoptera insect Asian corn borer(ACB)and two economically important spider mites Tetranychus truncatus Ehara and T.urticae Koch were investigated.In order to clarify the effect of GO itself on insects,the effect of GO itself on the growth and development of ACB must investigated firsty.The main results were as follows:(1)We examined the phenotypic responses of a lepidopteran insect Asian corn borer(ACB),Ostriniafurnacalis(Guenee),to graphene oxide(GO)exposure for over six generations.We demonstrated that GO can significantly promote the growth of ACB.The transcriptomic and proteomic results consistently verified that GO may activate trypsin-like serine protease,glutathione S-transferase,cytochrome P450s and glutathione S-transferase enzymes that further influence the development of ACB,Our findings may help to reveal the phenotypic,physiological and genetic responses of insects under exposure to nanomaterials and to assess the environmental risks of other nanomaterials.(2)In this work,the synergistic activity and mode of GO for insecticides against an lepidoptera insect ACB were investigated.The results demonstrated excellent synergistic activities of GO for the three types of insecticides(?-cyfluthrin(Cyf),Monosultap(Mon)and Imidacloprid(Imi)),The GO-Cyf,GO-Mon and GO-Imi mixtures exhibited 2.1-,1.51-and 1.83-fold higher contact toxicity than any single insecticide of Cyf,Mon and Imi.Our results indicated that the synergistic mechanism may be that(?)GO can cause'physical damage'to the cement layer of insects,resulting in a rapid water loss of the insects,(?)the disrupted cement layer provides a new channel for the penetration of insecticides,(?)the GO delivery system can enhance the efficacy of the insecticides.This multifunctional mechanism of GO to serve as a synergist for the existing insecticides suggests the great application potential of GO in pest management.(3)GO was synergistically used with three types of pesticides(pyridaben(Pyr),chlorpyrifos(Chl)and beta-cyfluthrin(Cyf)respectively as acaricide against two economically important spider mites,Tetranychus truncatus Ehara and T.urticae Koch.The results demonstrated that GO can enhance the activity of three types of pesticides.Compared with pesticides,the GO-Cyf,GO-Pyr and GO-Chl mixtures exhibited 1.77-,1.56-and 1.55-fold higher contact toxicity against T.truncatus,and 1.50-,1.75-,and 1.78-fold higher contact toxicity against T.urticae.SEM results showed that pesticide can adsorbed on the surface of GO.The synergistic mechanism may be that GO can serve as a carrier of pesticides,which can be adsorbed on the surface of mites and thus improve efficacy and utilization efficiency of pesticides.