Glufosinate (GF)

Glufosinate or its ammonium salt DL-phosphinothricin is an active ingredient in several nonselective systemic herbicides such as Basta, Rely, Finale, Ignite, Challenge, and Liberty. It interferes with the biosynthetic pathway of the amino acid glutamine and with ammonia detoxification. It has been used in pre-harvest crop desiccation. Some plants have been genetically modified for resistance to glufosinate. The gene which gives resistance to glufosinate is a bar or pat gene which was first isolated from two species of Streptomyces bacteria. There are glufosinate-resistant transgenic varieties of several crops, including cotton, canola, corn, soybean, sugarbeet, and rice. Phosphinothricin is an glutamine synthetase inhibitor that binds to the glutamate site. Glufosinate-treated plants die due to a buildup of ammonia and corresponding decrease in pH in the thylakoid lumen, leading to the uncoupling of photophosphorylation.