GLYPHOSATE-TOLERANT CROPS - GENES AND ENZYMES

This review focuses on the genes for the enzymes 5-enolpyruvyl-3-phosp hoshikimic acid synthase (EPSPS) and the glyphosate oxidoreductase (GO X), These genes have been used to genetically engineer plants that are resistant to the herbicide glyphosate, Overproduction of glyphosate-i nsensitive EPSPS in transgenic crops has been used to overcome the:del eterious effects of this herbicide. The introduction into plants of GO X also Confers glyphosate tolerance to plants and augments the toleran ce of transgenic plants already expressing a glyphosate tolerant EPSPS . These genes also provide a method for selecting transformed plant ti ssue using the glyphosate tolerance as the selectable marker in the pr esence of inhibitory concentrations of glyphosate. Glyphosate tolerant transgenic plants of beet, corn, cotton, lettuce, poplar, potato, rap eseed, soybean, tobacco, tomato, end wheat have already been field tes ted and are entering agriculture.