The acetolactate synthase enzyme (ALS) plays a key role in the
biochemical pathways of the branched-chain amino acids leucine,
isoleucine and valine. The application of ALS-inhibiting herbicides
blocks this synthesis pathway. Lack of the aforementioned amino
acids interferes with protein synthesis, causing the plant to die
off.This gene encodes a modified acetolactate synthase, which
confers tolerance to several acetolactate synthase-inhibiting
herbicides such as, for example, sulfonylurea.