Glyphosate is the active compound in the herbicide Roundup. It inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, which is required to synthesize the aromatic amino acids tryptophan, tyrosine, and phenylalanine. Plants sprayed with glyphosate stop growing and die because they cannot make these aromatic amino acids needed for protein synthesis. Transgenic crop plants that contain a gene encoding the glyphosate-resistant bacterial enzyme CP4 EPSP synthase are called Roundup Ready plants and do not die when treated with glyphosate. Although the use of glyphosate as an herbicide to increase crop yields in Roundup Ready crops is well documented, there have been concerns about its detrimental effect on native plants and about possible human health hazards resulting from chronic exposure to high levels of glyphosate. Moreover, because glyphosate-resistant weeds are becoming more common, there is a need to develop alternate approaches to sustainable agriculture in order to meet predicted global food shortages.
