Summary for Inhibitors of Amino Acid Biosynthesis
Chemicals which impair a plant’s ability to synthesize amino acids will have herbicidal effects because amino acids are necessary for protein biosynthesis; and proteins are essential in plant growth and development. The DNA code dictates the order of amino acids. The shape of the overall protein resulting from these amino acid interactions, defines the protein’s role. Therefore, a change in the gene sequence can result in an altered protein shape and function.
The class of herbicides which inhibit the production of aromatic amino acids was described at length. The enzyme, EPSP synthase, plays a vital role in the shikimate pathway, where aromatic amino acids are produced. Glyphosate, a non-selective herbicide, inhibits EPSP synthase as well as deregulates the shikimate pathway, leading to plant death. Through biotechnology and rare natural mutations, both resistant crops and weeds have been developed. In crops, researchers have transfered a soil bacteria gene which encodes an EPSP synthase enzyme that does not bind to glyphosate, yet maintains the ability to bind to PEP. This has given producers an extra tool they can use for weed management in some crops.