Safety Assessment Of Genetically Modified Crops In The Process Of Commercialization In China

Seed is the "chip" of agriculture.Developing molecular breeding technology is a new historical opportunity to promote the development of Chinese agriculture.Genetically modified(GM)breeding technology is one of the most popular,mature,and widely used technology in the field of crop molecular breeding.The cultivation of GM crops has produced considerable economic and ecological benefits,but it has also raised concerns about the biosafety.Therefore,the research on biosafety assessment of GM crops has important practical significance.In this study,GM soybean,corn,and cotton,which have the largest planting area in the world,are selected as the research objects.Among them,GM soybean and GM corn have not been commercially planted in China,but they have obtained biosafety certificates and are being planted in many pilot areas,while GM cotton has been widely cultivated in China for more than 25 years.It is necessary to assess the biosafety of GM soybeans and GM corn before they are commercially planted in China,and pay attention to the socio-economic and ecological benefits of Bt cotton after many years of commercial planting in China.Based on the theories and research methods of ecology,biology and sociology,this study adopts a variety of modern scientific and technological means to evaluate the safety of three major GM crops(soybean,corn and cotton)at different stages of commercialization in China.The main research results are as follows:1.Based on the bibliometrics analysis of the recent two decades of GM safety assessment,the results show that the relevant studies on the safety assessment of GM crops are increasing,and the main research directions of researchers are gene flow,the impact on non-target organisms,target pest resistance and food safety.The risk of gene flow is uncertain;GM crops had no significant effect on non-target organisms.Targeted pest resistance is more likely to occur in countries with large areas of single GM crops.There is no credible evidence that GM foods have adverse effects on human and vertebrate health.2.The effects of two GM maize on non-target arthropods in the field were investigated for 3 years.The results showed that:(1)the biodiversity difference of arthropod communities between GM maize and non-MG maize was smaller than that between different conventional cultivars;(2)the differences between ground-dwelling arthropod communities were less obvious than those between plant-inhabiting arthropod communities;and(3)Lepidopteron,the target pests of Bt maize,were not the dominant population in maize fields,and the dominant arthropod population in maize fields varied greatly between years and months.3.The effects of seven varieties of GM maize on target pests in two regions of Inner Mongolia and Yunnan were studied by field investigation.The results showed that:(1)Bt corn varieties have a certain control effect on target pests(Ostrinia furnacalis,Helicoverpa armigera,Mythimna separata,Spodoptera frugiperda);(2)There was no significant difference in the control effect of Bt maize and non-GM maze treated with insecticide on lepidoptera pests;(3)There were no significant effect between Bt maize and non-GM maze treated with insecticide on yield protection or increase under the condition of mild pest infestation.4.The lipidomics of GM soybean and non-GM soybean seeds was analyzed by the Matrix-assisted laser desorption/ionisation-mass spectrometry imaging(MALDI-MSI).A total of 184 lipids were successfully detected in GM and non-GM soybean seeds.Among which 22 lipids and 19 lipids were uniquely detected in GM and non-GM soybean seeds,respectively.There were 143 lipids detected in both two kinds of seeds.18 lipids with significant differences in the abundance and distribution were further identified in two soybean seeds.These lipids mainly belong to phosphatidylcholines,phosphatidylethanolamines,cytidine dipho-sphate-diacylglycerols and triacylglycerols.These results indicated that the insertion and expression of epsps and pat herbicidetolerant genes caused unintended changes in lipids of soybean seed.5.MALDI-MSI was used for detection and imaging of protein changes in the seeds of herbicide-resistant GM soybean with epsps and pat genes,non-GM soybean,wild soybean,and GM hybrid wild soybean F2.The results showed that the protein composition,abundance and spatial distribution of the four soybean seeds were different.The difference in seed protein between GM soybean and non-GM soybean was the smallest,and the difference of seed protein between wild soybean and other soybeans was the largest.F2 seeds possess both the protein characteristics of their parents.Using the ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-QTOF-MS),22 differentially expressed proteins were identified,including 13 specifics to wild soybean.No unintended up-regulated expression of allergic protein was found in GM soybean and F2.Stress response-related differentially expressed proteins were lower in F2 than in wild soybean seeds.6.The cognition and assessment of Bt cotton were investigated by questionnaires and interviews among cotton farmers in Handan,Hebei,Dezhou,Shandong,and Changji,Xinjiang.The results showed that:(1)cotton farmers lack understanding of GM cotton,most of them are not clear about the relationship between GM cotton and the insect-resistant cotton,but most of them support the insect-resistant cotton;(2)In the cotton region of Yellow River represented by Handan and Dezhou,the occurrence and damage rate of cotton bollworm were significantly reduced,The times of pesticide spraying were reduced,and economic income was significantly increased;(3)In the cotton region of Xinjiang represented by Changji,since bollworm has been less harmful in the past 20 years,insect-resistant cotton and conventional cotton have not shown significant differences in insect resistance,pesticide spraying times and income;After planting Bt cotton in Handan and Dezhou,there were significant changes in the occurrence of field insect pests.After the number of cotton bollworm decreased,lygus,aphids and red spider mite gradually increased from secondary pests to main pests.Means of production and labor cost are the main factors affecting farmers’ choice of crop planting,while insect resistance is a secondary factor.GM corn,soybean and cotton are used for feeding,food and industrial use respectively,so they are based on different concerns and the industrialization process being promoted in China.Safety assessment of three GM crops was studied in this paper.The results will provide an important experimental basis for promoting the industrialization of GM crops,and provide an effective assessment method.