Highly Efficient Agrobacterium tumefaciens Mediated Transformation of Oil Palm Using an EPSPS-Glyphosate Selection System

Oil palm (<i>Elaeis guineensis</i> Jacq.) is the most efficient oil-producing crop globally, yet progress in its research has been hampered by the lack of effective genetic transformation systems. The <i>EPSPS</i> gene, encoding 5-enolpyruvylshikimate-3-phosphate synthase, has been used as a transgenic selection marker in various crops, including rice and soybean. This study evaluated the <i>EPSPS</i>/glyphosate selection system for oil palm transformation. We constructed a binary expression vector, pCGlyDESCLI-C, containing the <i>TIPS-EiEPSPS</i> selection marker from goosegrass and the <i>mScarlet-I</i> red fluorescent reporter gene. This vector was introduced into oil palm embryonic callus (EC) via <i>Agrobacterium</i>-mediated transformation. After optimizing the transformation steps, positive calli were obtained, and integration of the foreign gene into the oil palm genome was confirmed through molecular analysis. Notably, the selection efficiency of the <i>EPSPS</i>/glyphosate selection system exceeded that of the traditional <i>hpt</i>/hygromycin selection system, demonstrating its advantages. Our findings support the effectiveness of the <i>TIPS-EiEPSPS</i>/glyphosate selection system for oil palm genetic transformation, marking its first application in this species and offering a valuable tool for advancing research on this economically significant crop.