20.2  Biochemistry of herbicide resistance

Printer-friendly version

Herbicides inhibit essential biochemical reactions and there-fore the resistance genes must encode biochemical traits endowing resistance. The biochemical process that a herbicide directly affects is termed the target site, often a single enzyme that is vital for plant survival. Therefore when herbicides bind to a target site and inhibit or modify normal function they will impair plant function, often terminally. Resistance to herbicides is thus likely to involve either modification of the target site enzyme or a decrease in herbicide concentration at the target site.