Assessment of potential gene flow from resveratrol-enriched genetically modified rice to non-genetically modified rice and weedy rice

Genetically modified (GM) rice has been developed to introduce and enhance desirable traits in rice, including tolerance to abiotic and biotic stresses, resistance to pests and diseases, and improved grain quality. However, several concerns remain regarding the safety of GM rice for human health and its potential environmental impacts, particularly the risk of gene flow from GM rice to non-GM and weedy rice varieties. Numerous studies on GM crops have reported gene flow events between GM rice and related plants under field conditions. To address these safety concerns, this study investigated pollen-mediated gene flow from resveratrol-enriched GM rice Agb0102 to the non-GM rice cultivar Dongjin and weedy rice R55 over a 3-year period. The results revealed an average gene flow frequency of 0.014% and 0.003% from GM rice to non-GM rice and weedy rice, respectively. Gene flow events were primarily confined to plants growing within a 1-m radius, with the highest frequency (0.058%) observed in Dongjin plants at a distance of 30 cm from Agb0102 plants. This localized gene flow is likely promoted by overlapping flowering times and genome compatibility between GM and non-GM rice. Additionally, wind direction and insect-mediated pollination may explain the occurrence of three out-crossing events in the R55 weedy rice pool, with the farthest event detected at 600 cm from Agb0102 plants. These findings provide valuable insights into the dynamics of gene flow in GM rice cultivation and highlight the need for risk assessment and management strategies to mitigate potential ecological impacts of GM rice in large-scale field conditions.