<p style="text-align: justify;">Teal 11A (Clearfield&trade;) spring wheat was developed to allow the use of imazamox and imazethapyr, both imidazolinone herbicides, as weed control options in spring wheat production. This trait was developed using chemically induced seed mutagenesis and whole plant selection procedures. This wheat line expresses a mutated form of the acetohydroxyacid synthase (AHAS) enzyme, which renders the plant tolerant to levels of imazamox and imazethapyr used in weed control.</p>

<p style="text-align: justify;">AHAS catalyses the first step in the biosynthesis of the branched-chain amino acids isoleucine, leucine, and valine, and is active in the glycolytic pathway of plant metabolism. When conventional plants are treated with either imazamox or imazethapyr, the herbicide binds to a specific site on the enzyme, thereby inhibiting its activity. The result of this enzyme inhibition is a decrease in the synthesis of these amino acids, and an accumulation of toxic levels of alpha-ketoglutarate, all of which results in the eventual death of the plant.</p>
