Phosphinothricin acetyltransferase (PAT (sometimes "BAR" when using the bar gene variant))

The phosphinothricin acetyltransferase (PAT) gene, derived from the soil bacteria *Streptomyces hygroscopicus* (bar) or *Streptomyces viridochromogenes* (pat), encodes an enzyme (PAT) that detoxifies the herbicide glufosinate (phosphinothricin) by acetylation. Transgenic crops expressing this gene are rendered tolerant to glufosinate by converting the herbicide into N-acetyl-glufosinate, a non-toxic compound that can no longer inhibit the endogenous plant enzyme glutamine synthetase—thus ensuring crop survival after herbicide application. This gene is used as a selectable marker and trait gene in various genetically modified crops such as maize, cotton, and canola. "Glufosinate tolerance gene" should be replaced with the precise name of the conferred trait gene, "phosphinothricin acetyltransferase." Key extra details: - Mechanism: Glufosinate acts by inhibiting plant glutamine synthetase, causing ammonia toxicity and death. The PAT enzyme catalyzes acetylation of glufosinate, rendering it unable to bind glutamine synthetase, thereby protecting transformed plants. - Commercial use: Present in LibertyLink® and other glufosinate-tolerant crops. - Transgene marker: Used for selection during the generation of GM plants. Glufosinate tolerance can rarely arise via mutations in plant glutamine synthetase genes, but in agricultural biotechnology, the term almost always refers to the bacterial PAT/BAR transgene.

Other names

bar genepat genephosphinothricin N-acetyltransferase geneBasta resistance gene

Acetylation (detoxification) of glufosinate to non-toxic N-acetyl-glufosinate