The Risk Assessment Of Four Proteins Expressed By Transgenic Maize On Chrysoperla Sinica Larvae

Since the commercialization of GM Bt corn in 1996,it has resulted in enormous economic benefits to people and drastically reduced the amount of insecticides applicatioin.Corn,as one of the major food and feed crops in China,has been affected by pests and weeds.Efforts to research and develop insects resistance and herbicide tolerance corn events have been carried out in academic institutions and private sectors and stimulated by National S&T Major Programs grants as well as private company funds.A couple of transgenic corn events such as IE034 and C0030.3.5 with excellent resistance to the Asian corn borer and glyphosate.However,before commercialization,genetically modified corn events must be evaluated for environmental safety,especially risk assessment for non-targets to ensure non-harmful on the environment.Chrysoperla sinica larvae is widely distributed in China,is a common predator of farmland ecosystems.It preys on aphids,Lepidopteran eggs and larvae,planthoppers and other pests.It is a common insect natural enemy in maize field and has important significance in biological control.C.sinica larvae can exposed to insecticidal protein and herbicide resistance protein by preying on aphids,mites and other insects who feed on transgenic corn plants.In this study,the risk assessment of Cry1Ab,PAT,EPSPS and Cry1Ie proteins expressed by transgenic corn events IE034 and C0030.3.5in China on C.sinica larvae was studied.The results are as follows:?1?The Cry1Ab,PAT and EPSPS proteins expressed by transgenic corn mixed with artificial diet of C.sinica were studied for the effects on the growth and development of C.sinica larvae.Diet mixed with potassium arsenate?PA,KH₂As O₄?was as a positive control.The results showed that Compared with the control,the pupation rate of C.sinica was significantly decreased when they fed on diet containing PA compared with that fed on normal diet.PA was adversely affected on C.sinica larval development and survival,which confirmed this bioassay method is functional.The biological parameters,including pupation rate,eclosion rate,larval development time,pupation development time,adult fresh weight of C.sinica,were not affected when larvae fed on the diet contained purified Cry1Ab or EPSPS.Compared with the control,the development time of larvae was significantly shortened and the pupation rate was signif icantly increased while they fed on diet containing PAT.The ELISA results showed that the content of Cry1Ab protein was 2758.8⁵210.7ng/g,EPSPS protein was35018.0⁵4426.6 ng/g,PAT protein was 16.8¹49.8 ng/g in the larvae fed on diet containing those proteins.The experiments demonstrate that the Cry1Ab,EPSPS and PAT proteins expressed by transgenic corn have no adverse effects to C.sinica larvae.?2?The Cry1Ie protein expressed by transgenic corn IE034 mixed with artificial diet were studied for the effects on the growth and development of C.sinica larvae,using the established dietary assay.In addition,the growth,digestive enzymes,nutrient status of those larvae were studied.The results showed that the biological parameters,including pupation rate,eclosion rate,larval development time,pupation development time,adult fresh weight of C.sinica larvae were not affected when they fed on the artificial diet contained Cry1Ie protein.In contrast,C.sinica larvae were adversely affected when the diet contained PA.The activity of general protease,trehalase and lipase of the larvae,were not signif icantly different between normal diet and Cry1Ie-diet treatments.Compared with the normal diet,the total protein,glycogen,trehalose and fat content of the larvae fed with Cry1Ie protein were not signif icantly different.The experiments demonstrate that the Cry1Ie protein expressed by transgenic corn have no adverse effects to C.sinica larvae.