Properties of Mutant Acetolactate Synthases Resistant to Triazolopyrimidine Sulfonanilide
- 1 September 1990
- journal article
- research article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 94 (1) , 239-244
- https://doi.org/10.1104/pp.94.1.239
Abstract
Triazolopyrimidine sulfanilides are a class of highly active herbicides whose primary target is acetolactate synthase. Spontaneous mutants of tobacco (Nicotiana tabacum) (KS-43) and cotton (Gossypium hirsutum) (PS-3 and DO-2) resistant to triazolopyrimidine sulfonanilide were selected in tissue cuture. Acetolactate synthase partially purified from the three mutants were 80- to 1000-fold less sensitive to inhibition by the compound compared with the corresponding wild-type enzyme. The mutants also varied in the cross-resistance pattern to other acetolactate synthase inhibiting herbicidies in the sulfonylurea, imidazolinone, and pyrimidyl-oxy-benzoate chemical families. Thus, acetolactate synthase from KS-43, PS-3, and DO-2 cultures have different mutations. The affinities for pyruvate, thiamine pyrophosphate, as well as the activity of the mutant enzymes were found to be comparable to the corresponding wild-type enzymes. However, the enzyme from PS-3 was highly resistant to feedback inhibition by valine and leucine. In contrast, acetolactate synthase from KS-43 and DO-2 were inhibited by valine and leucine to nearly the same extent as the wild-type enzymes. Also, PS-3 cultures accumulated much higher levels of the branched amino acids compared to the wild-type cotton culture. The mutation in the PS-3 enzyme has therefore rendered it insensitive to feedback regulation by valine and leucine.This publication has 13 references indexed in Scilit:
- Cross-Resistance to Short Residual Sulfonylurea Herbicides in Transgenic Tobacco PlantsPlant Physiology, 1989
- Herbicide Resistance in Datura innoxiaPlant Physiology, 1988
- Imidazolinones and Acetohydroxyacid Synthase from Higher PlantsPlant Physiology, 1987
- Sensitivity of a Salmonella typhimurium aspC mutant to sulfometuron methyl, a potent inhibitor of acetolactate synthase IIJournal of Bacteriology, 1986
- ImidazolinonesPlant Physiology, 1984
- The sulfonylurea herbicide sulfometuron methyl is an extremely potent and selective inhibitor of acetolactate synthase in Salmonella typhimurium.Journal of Biological Chemistry, 1984
- Site of Action of ChlorsulfuronPlant Physiology, 1984
- Herbicide-Resistant Mutants from Tobacco Cell CulturesScience, 1984
- PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENTJournal of Biological Chemistry, 1951
- A COLORIMETRIC DETERMINATION OF BLOOD ACETOINJournal of Biological Chemistry, 1945