Phosphinothricin

Phosphinothricin (also known as glufosinate) is a naturally occurring broad-spectrum herbicide produced by several species of Streptomyces bacteria. It is a non-selective herbicide that is used to control a wide range of weeds after the crop emerges or for total vegetation control on land not used for cultivation.

Chemistry

Phosphinothricin is a phosphinic acid containing two amino acids, alanine and glutamic acid. It is a white crystalline solid with a melting point of 200-202 °C. It is soluble in water and most organic solvents.

Mode of Action

Phosphinothricin acts by inhibiting the enzyme glutamine synthetase, which is necessary for the synthesis of glutamine and for ammonia detoxification. The inhibition of this enzyme leads to a buildup of ammonia in the plant, which is toxic and leads to plant death.

Usage

Phosphinothricin is used as a herbicide in agriculture, especially in the cultivation of genetically modified crops that have been engineered to be resistant to it. It is also used in the control of invasive species.

Safety

Phosphinothricin is of low toxicity to humans and animals. However, it can cause irritation to the eyes and skin, and may be harmful if swallowed or inhaled.

Environmental Impact

Phosphinothricin is rapidly degraded in the soil by microorganisms, with a half-life of 3 to 60 days. It has low potential for bioaccumulation, but its use can affect non-target organisms in the soil.

See Also

• Herbicide
• Glutamine synthetase
• Streptomyces