Glutamine synthetase inhibitors

Phytopathogenic Pseudomonas strains were the first organisms that exploited this Achilles heel of plants P. syringae pv tabaci produce the glutamine synthetase inhibitor tabtoximine-j8-lactam, which enables the pathogen to colonize the host tissue killed by the toxin. 

The natural glutamine synthetase inhibitor phosphinothricin as well as its synthetic racemate glufosinate are broad spectrum post-emergent herbicides that will play a role in future agriculture due to the unique mode of action. Because these GS inhibitors fully control weeds that have evolved resistances against other types of herbicides, the use of phosphinothricin-containing herbicides in tolerant crops will remain an important option for future sustainable agriculture. 

In the original review article (Miflin and Lea, 1980) the use of the glutamine synthetase inhibitor L-methionine-5-sulfoximine (MSO) was discussed in some detail. Since that time a range of new inhibitors has been employed in studies on plant metabolism (see Lea and Ridly, 1989, for a complete review). 

---