Effects of genetically modified maize expressing Cry1Ab and EPSPS proteins on Japanese quail

Changes in the Stress Response and Fitness of Hybrids Between Transgenic Soybean and Wild-Type Plants Under Heat Stress

Understanding the ability of hybrids of genetically modified (GM) soybean and wild soybean to survive and reproduce under unfavorable conditions is critical for answering questions regarding risk assessment and the existence of transgenes in the environment. To investigate the effects of high-temperature stress on soybean growth and competitive ability, the GM soybean DBN8002, which expresses the VIP3Aa and PAT proteins, and F2 generations derived from a cross between GM soybean and NJW (wild soybean) were placed in a greenhouse with an elevated temperature (38/32 °C) for 14 days, and the plant agronomic performance and foreign protein levels of hybrid soybean were evaluated to observe their responses to high temperature. The results revealed that the VIP3Aa and PAT protein levels in F2 and GM were not influenced by high-temperature stress. In contrast, the pollen germination, pod number, hundred-seed weight, and seed vigor of the F2 hybrid and parent soybean plants decreased after high-temperature stress. However, except for the number of fully filled seeds per plant, the above parameters of the F2 hybrid were similar to or slightly lower than those of wild soybean, and no significant difference in fitness was observed between the F2 hybrid and wild soybean, indicating that the growth and competitive ability of the hybrid were similar to those of its female parent under heat stress conditions, resulting in the transgenes persisting and spreading within agricultural ecosystems. Our results enhance the understanding of the GM soybean plant's response to heat stress, lay the foundation for breeding heat-resistant soybean varieties, and provide new insights and advanced information on the ecological risks arising from the escape of transgenes.

Multigenerational effects of cultivating transgenic maize straw on earthworms: A combined laboratory and field experiment

The cultivation of genetically modified (GM) maize has aroused notable public concern related to the potential risks to soil fauna caused by the release of foreign proteins. In this study, the potential effects of cultivating the GM maize variety DBN9936, which exhibits the expression of the Cry1Ab and EPSPS proteins, on earthworms (Eisenia fetida) were evaluated under laboratory and field conditions. No significant differences in the survival, body weight, cocoon production, or hatching of earthworms fed GM or non-GM DBN318 maize were detected after three consecutive generations in a laboratory test. The enzymatic activity assay results revealed no significant differences in superoxide dismutase (SOD) or catalase (CAT) enzyme activity between the GM and non-GM maize varieties. Furthermore, exogenous Cry1Ab and EPSPS proteins were undetectable in the gut tissues of earthworms raised with GM maize straw. GM maize cultivation imposed no adverse effects on the species composition or density of soil earthworms in the two consecutive years during the field test, and the soil earthworm species, total number of earthworms and density of each earthworm species did not significantly differ between the GM maize and non-GM maize lines. On the basis of our findings, we concluded that the cultivation of the GM maize variety DBN9936 does not pose a risk to earthworms.

A 90-day rodent feeding study with grain for genetically modified maize L4 conferring insect resistance and glyphosate tolerance

A 90-day rat feeding study was performed to conduct a safety assessment on L4, a multi-gene genetically modified maize, conferring "Bt" insect resistance and glyphosate tolerance. A total of 140 Wistar rats were assigned to seven groups, 10 animals/group/sex, which comprised three genetically modified groups fed diets containing different concentrations of L4, three corresponding non-genetically modified groups fed diets containing different concentrations of zheng58 (parent plants), and a basal diet group fed the standard basal diet for 13 weeks. The fed diets contained L4 and Zheng58 at w/w% percentages of 12.5%, 25.0%, and 50% of the total. Animals were evaluated on some research parameters, including general behaviour, body weight/gain, feed consumption/efficiency, ophthalmology, clinical pathology, organ weights, and histopathology. Throughout the feeding trial, all animals were in good condition. No mortality and no biologically relevant effects or toxicologically significant alterations were observed in the total research parameters of the rats in the genetically modified groups compared with those in the basal diet group or their corresponding non-genetically modified groups. No adverse effects were observed in any of the animals. The results indicated that L4 is as safe and wholesome as conventional, non-genetically modified control maize.

Effect of genetically modified maize expressing the Cry1Ab and EPSPS proteins on growth, development, and gut bacterial diversity of the non-target arthropod Locusta migratoria

The widespread cultivation of genetically modified (GM) crops has raised concerns for their safety. Here, we evaluated the effects of a GM maize variety expressing the Cry1Ab (14.76 ± 0.87 μg/g FW) and EPSPS proteins (191.55 ± 15.69 μg/g FW) on the life-history traits and gut bacterial community of a non-target arthropod, Locusta migratoria, in the laboratory. We found that GM maize had no significant effect on the survival or body weight of different development stages of L. migratoria. The midgut and hindgut bacterial diversities and compositions were determined using high-throughput sequencing targeting the V3-V4 regions of the 16S rRNA. No significant changes were found in the species diversity or abundance between insects in the GM-fed treatment and the non-GM control. Furthermore, the concentration of Cry1Ab and EPSPS in the gut was determined after digestion of GM maize. Results showed that the contents of Cry1Ab/EPSPS rapidly decreased and were hard to detect after 72 h. Based on the parameters assessed, we can conclude that the GM maize variety examined has no significant adverse effect on L. migratoria.