Mechanism of sulfonylurea herbicide resistance in the broadleaf weed, Kochia scoparia

Journal Article · Tue May 01 04:00:00 EDT 1990 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.93.1.55· OSTI ID:5957127

Saari, L L; Cotterman, J C; Primiani, M M ^[1]

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1. E.I. duPont de Nemours Co., Inc., Wilmington, DE (USA)

Selection of kochia (Kochia scoparia) biotypes resistant to the sulfonylurea herbicide chlorsulfuron has occurred through the continued use of this herbicide in monoculture cereal-growing areas in the United States. The apparent sulfonylurea resistance observed in kochia was confirmed in greenhouse tests. Fresh and dry weight accumulation in the resistance kochia was 2- to >350-fold higher in the presence of four sulfonylurea herbicides as compared to the susceptible biotype. Acetolactate synthase (ALS) activity isolated from sulfonylurea-resistant kochia was less sensitive to inhibition by three classes of ALS-inhibiting herbicides, sulfonylureas, imidazolinones, and sulfonanilides. The decrease in ALS sensitivity to inhibition (as measured by the ratio of resistant I{sub 50} to susceptible I{sub 50}) was 5- to 28-fold, 2- to 6-fold, and 20-fold for sulfonylurea herbicides, imidazolinone herbicides, and a sulfonanilide herbicide, respectively. No differences were observed in the ALS-specific activities or the rates of ({sup 14}C)chlorsulfuron uptake, translocation, and metabolism between susceptible and resistant kochia biotypes. The K{sub m} values for pyruvate using ALS from susceptible and resistant kochia were 2.13 and 1.74 mM, respectively. Based on these results, the mechanism of sulfonylurea resistance in this kochia biotype is due solely to a less sulfonylurea-sensitive ALS enzyme.

• OSTI ID: 5957127
• Journal Information: Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 93:1; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
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59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL ADAPTATION
CARBON 14 COMPOUNDS
CARBON-CARBON LYASES
ENZYME ACTIVITY
ENZYME INHIBITORS
ENZYMES
HERBICIDES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LYASES
MAGNOLIOPHYTA
MAGNOLIOPSIDA
METABOLISM
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PESTICIDES
PLANTS
REACTION KINETICS
THIOLS
TRACER TECHNIQUES
WEEDS