Edible Safety Assessment of Genetically Modified Rice T1C-1 for Sprague Dawley Rats through Horizontal Gene Transfer, Allergenicity and Intestinal Microbiota

Transfer and distribution of antibiotic resistance genes in the soil-peanut system receiving manure for years

Antibiotic resistance gene (ARG)-contaminated food from manure application is gaining widespread interest, but little is known about the distribution and uptake of ARGs in peanuts that are subjected to manure routinely. In this study, the ARG profile and bacterial community in soil and peanut plants from a 7-year manure-fertilized field were investigated using high-throughput qPCR and 16S rRNA gene sequencing. Manure application increased the abundance of ARGs in soil and peanuts by 59-72 and 4-10 fold, respectively. The abundance of ARGs from high to low was as follows: manure, shell-sphere soil, rhizosphere soil, bulk soil, stems, shells, needles, kernels, and roots. Source-tracker analyses were used to investigate the potential source of ARGs in peanut kernels, which revealed that the ARGs in peanut kernels may be primarily absorbed by the roots from the soil. The horizontal gene transfer (HGT) of ARGs was the primary factor in the spread of ARGs, and Proteobacteria were the primary agents of HGT between different parts of peanut plants. Additionally, norank_Chloroplast from the phylum Cyanobacteria was the most important contributor to the abundance of ARGs in peanut kernels. Overall, our findings fill a gap in our understanding of the distribution patterns of ARGs in peanut plants and the migratory pathways of ARGs from soil to peanut kernels.

Combined metagenomic and metabolomic analyses reveal that Bt rice planting alters soil C-N metabolism

The environmental impacts of genetically modified (GM) plants remain a controversial global issue. To address these issues, comprehensive environmental risk assessments of GM plants is critical for the sustainable development and application of transgenic technology. In this paper, significant differences were not observed between microbial metagenomic and metabolomic profiles in surface waters of the Bt rice (T1C-1, the transgenic line) and non-Bt cultivars (Minghui 63 (the isogenic line) and Zhonghua 11 (the conventional japonica cultivar)). In contrast, differences in these profiles were apparent in the rhizospheres. T1C-1 planting increased soil microbiome diversity and network stability, but did not significantly alter the abundances of potential probiotic or phytopathogenic microorganisms compared with Minghui 63 and Zhonghua 11, which revealed no adverse effects of T1C-1 on soil microbial communities. T1C-1 planting could significantly alter soil C and N, probably via the regulation of the abundances of enzymes related to soil C and N cycling. In addition, integrated multi-omic analysis of root exudate metabolomes and soil microbiomes showed that the abundances of various metabolites released as root exudates were significantly correlated with subsets of microbial populations including the Acidobacteria, Actinobacteria, Chloroflexi, and Gemmatimonadetes that were differentially abundant in T1C-1 and Mnghui 63 soils. Finally, the potential for T1C-1-associated root metabolites to exert growth effects on T1C-1-associated species was experimentally validated by analysis of bacterial cultures, revealing that Bt rice planting could selectively modulate specific root microbiota. Overall, this study indicate that Bt rice can directly modulate rhizosphere microbiome assemblages by altering the metabolic compositions of root exudates that then alters soil metabolite profiles and physiochemical properties. This study unveils the mechanistic associations of Bt plant-microorganism-environment, which provides comprehensive insights into the potential ecological impacts of GM plants.

Horizontal gene transfer from genetically modified plants - Regulatory considerations

Gene technology regulators receive applications seeking permission for the environmental release of genetically modified (GM) plants, many of which possess beneficial traits such as improved production, enhanced nutrition and resistance to drought, pests and diseases. The regulators must assess the risks to human and animal health and to the environment from releasing these GM plants. One such consideration, of many, is the likelihood and potential consequence of the introduced or modified DNA being transferred to other organisms, including people. While such gene transfer is most likely to occur to sexually compatible relatives (vertical gene transfer), horizontal gene transfer (HGT), which is the acquisition of genetic material that has not been inherited from a parent, is also a possibility considered during these assessments. Advances in HGT detection, aided by next generation sequencing, have demonstrated that HGT occurrence may have been previously underestimated. In this review, we provide updated evidence on the likelihood, factors and the barriers for the introduced or modified DNA in GM plants to be horizontally transferred into a variety of recipients. We present the legislation and frameworks the Australian Gene Technology Regulator adheres to with respect to the consideration of risks posed by HGT. Such a perspective may generally be applicable to regulators in other jurisdictions as well as to commercial and research organisations who develop GM plants.

No Effect of Bt-transgenic Rice on the Tritrophic Interaction of the Stored Rice, the Maize Weevil Sitophilus Zeamais and the Parasitoid Wasp Theocolax elegans

During Bt transgenic rice storage, Bt Cry1Ab/Cry1Ac fused protein is exposed to the maize weevil Sitophilus zeamais and the parasitoid wasp Theocolax elegans. We have carried out a long-term risk assessment for Bt rice to these non-target organisms in the storehouse. Effects of Bt rice on S. zeamais and T. elegans have been carefully detected in a laboratory experiment of over 5 years. The survival, development, fecundity, and longevity of the maize weevil were compared between Bt rice and non-Bt rice treatments for every 5 generations from generation 1 to 25. Moreover, the development, adult body size and sex ratio of T. elegans were compared between them parasitizing S. zeamais feeding on Bt rice or non-Bt rice. We found that although Bt Cry1Ab/Cry1Ac fused protein exists in the Bt rice grains and S. zeamais digestive tracts, Bt rice is not harmful to the maize weevil S. zeamais and its parasitoid T. elegans.

Impact on environment, ecosystem, diversity and health from culturing and using GMOs as feed and food

Modern agriculture provides the potential for sustainable feeding of the world's increasing population. Up to the present moment, genetically modified (GM) products have enabled increased yields and reduced pesticide usage. Nevertheless, GM products are controversial amongst policy makers, scientists and the consumers, regarding their possible environmental, ecological, and health risks. Scientific-and-political debates can even influence legislation and prospective risk assessment procedure. Currently, the scientifically-assessed direct hazardous impacts of GM food and feed on fauna and flora are conflicting; indeed, a review of literature available data provides some evidence of GM environmental and health risks. Although the consequences of gene flow and risks to biodiversity are debatable. Risks to the environment and ecosystems can exist, such as the evolution of weed herbicide resistance during GM cultivation. A matter of high importance is to provide precise knowledge and adequate current information to regulatory agencies, governments, policy makers, researchers, and commercial GMO-releasing companies to enable them to thoroughly investigate the possible risks.