Detection of Genetically Modified Glyphosate-Resistant Soybean Sold in Sarawak

Abstract

A genetically modified (GM) crop is an organism whose genetic makeup has been altered to express the desired physiological traits. Soybean (Glycine max) is a common GM crop. Its genome has been genetically engineered to confer resistance to herbicides, pests and extreme environmental conditions. Mislabelling of food products as GM-free has triggered insecurity among consumers. In addition, the health effects due to consumption of GM foods remains controversial. Therefore, this study aimed to identify the presence of GM soybean in animal feeds and several food products such as raw soybean, tempeh, and tofu collected from Sarawak traditional markets, grocery stores, and supermarkets. The presence of the regulatory elements CaMV 35S Promoter (P35S) and NOS Terminator (TNOS) were initially screened using conventional Polymerase Chain Reaction (PCR). Then, all samples were subjected to the PCR-based construct-specific method by targeting the cp4 epsps gene, which confers glyphosate-resistance. Positive samples were validated through DNA sequencing. The result demonstrated that 56 out of 65 samples including 17 soybean, 12 animal feeds, 7 tofu and 20 tempeh samples were positive for cp4 epsps. Furthermore, 2 out of 20 raw soybean samples were labelled as GM-free. However, validation using DNA sequencing indicates 100% identity to cp4 epsps gene in comparison with the Genbank database. This study demonstrated the significance of GM detection in soybean and the importance of accurate food labelling.