Development of an immunochromatographic strip for rapid detection of recombinant rice EPSPS in transgenic crops

Glyphosate-resistant crops, developed using the EPSPS gene, are widely cultivated globally. Previous studies indicate that the TIPS-OsEPSPS gene provides glyphosate resistance in rice. In this research, the OsmEPSPS gene was utilized to develop glyphosate-resistant, maize, and soybean, and a rapid immunochromatographic strip (ICS) test was designed for specific detection of the OsmEPSPS protein. The ICS test employs a double-antibody sandwich format with two monoclonal antibodies: mAb #9, conjugated to colloidal gold for capture, and mAb #15, for detection at the test line. The ICS exhibited a limit of detection (LOD) of 0.031 μg/mL within 10 min. Additionally, the ICS could detect a concentration of 0.817 μg/mL within 1 min in both Eleusine indica and OsmEPSPS-overexpressing plants. The ICS is highly specific, sensitive, and stable, with an R² value of 0.982. Notably, the ICS is capable of detecting EPSPS proteins with high homology to OsmEPSPS from Poaceae and other plants. In summary, this study developed a sensitive and specific test strip for OsmEPSPS detection, facilitating semiquantitative analysis on the basis of colorimetric response time and intensity. This ICS is not only suitable for the rapid identification of OsmEPSPS-overexpressing plants but also for phylogenetic analysis of EPSPS gene homology.