Cross-resistance of a chlorsulfuron-resistant biotype of Stellaria media to a triazolopyrimidine herbicide

• Published in: Plant physiology (Bethesda) Vol. 93; no. 3; pp. 962 - 966
• Main Authors: Hall, L.M. (University of Saskatchewan, Saskatoon, Saskatchewan, Canada), Devine, M.D
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.07.1990
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Agronomy. Soil science and plant productions; ALBERTA; Amyotrophic lateral sclerosis; Binding sites; Biological and medical sciences; Biosynthesis; CARYOPHYLLACEAE; Chemical control; COMPOSE ORGANOCHLORE; COMPUESTO ORGANICO DEL CLORO; Crop harvesting; Cross resistance; Enzymes; Fundamental and applied biological sciences. Psychology; HERBICIDAS; HERBICIDE; Herbicide resistance; Herbicides; LIGASA; LIGASE; MALEZAS; MAUVAISE HERBE; Parasitic plants. Weeds; PESTICIDE; Phytopathology. Animal pests. Plant and forest protection; PLAGUICIDAS; Plants; RESISTANCE AUX PRODUITS CHIMIQUES; RESISTENCIA QUIMICA; Salmonella; Weeds; Stellaria media; Weed; Dicotyledones; Angiospermae; Sulfonylureas; Biotype; Triazole derivatives; Pyrimidine derivatives; Spermatophyta; Cross resistance; Caryophyllaceae; Herbicide
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.93.3.962

A biotype of Stellaria media (L.) Vill. has been identified that is highly resistant to the herbicide chlorsulfuron. Resistance is due to an altered acetolactate synthase (ALS) that is much less sensitive to chlorsulfuron than the ALS from the susceptible (S) biotype. The S biotype was extremely sensitive to D489 (N-[2,6-dichlorophenyl]-5,7-dimethyl-1,2,4-triazolo[1,5a]pyrimidine-2-sulfonamide), a number of a new class of triazolopyrimidine herbicides, while the chlorsulfuron-resistant biotype exhibited complete cross-resistance at both the whole plant and enzyme levels. ALS activity of the S biotype was reduced by approximately 90% in the presence of 0.1 micromolar D489, while that of the R biotype was reduced by less than 10%. This result suggests that the two herbicides share a common binding site on ALS. Only very slight cross-resistance at the ALS level was found to imazamethabenz, an imidazolinone herbicide