ARS | Publication request: PROTOPORPHYRINOGEN OXIDASE INHIBITORS -- THEIR CURRENT AND FUTURE ROLES

Submitted to: International Weed Control Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 28, 1996
Publication Date: N/A

Technical Abstract: Inhibitors of protoporphyrinogen oxidase (Protox) are highly efficacious herbicides with many desirable traits. Thousands of excellent Protox inhibitors from many different chemical classes have been discovered. However, their usefulness is limited by their similar selectivity patterns and methods of use in the relatively few crops in which they can be used. A growing asset of this herbicide class is that weeds have not evolved resistance to them. Selectivity of Protox inhibitors might be manipulated by producing Protox proherbicides, the selectivity of which would be determined at the bioactivation stage. Theoretically, safeners could be used with susceptible crops to extend Protox inhibitor use. Creation of Protox inhibitor-resistant crops with biotechnology is problematic, in that no eucaryotic, organellar Protox has yet been demonstrated unequivocally to be resistant. However, manipulation of other enzyme activities, such as the enzyme(s) that rapidly degrades protoporphyrinogen IX to nontoxic compounds could be a route to produce herbicide-resistant crops, thus, greatly expanding the use of these highly efficacious herbicides.