Tembotrione detoxification in 4‐hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor‐resistant Palmer amaranth (Amaranthus palmeri S. Wats.)

• Published in: Pest management science Vol. 74; no. 10; pp. 2325 - 2334
• Main Authors: Küpper, Anita, Peter, Falco, Zöllner, Peter, Lorentz, Lothar, Tranel, Patrick J, Beffa, Roland, Gaines, Todd A
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.10.2018; Wiley Subscription Services, Inc
• Subjects: 4-Hydroxyphenylpyruvate Dioxygenase - antagonists & inhibitors; Amaranth; Amaranthus - drug effects; Amaranthus - enzymology; Amaranthus - metabolism; Amaranthus palmeri; Biotypes; Cyclohexanones - metabolism; Cyclohexanones - pharmacology; Cytochrome; Cytochrome P450; cytochrome P450 enzyme; Cytochromes P450; Detoxification; enhanced metabolism; Glycosylation; Herbicide resistance; Herbicide Resistance - physiology; Herbicides; Herbicides - metabolism; Herbicides - pharmacology; Hydroxylation; Hydroxyphenylpyruvate dioxygenase; Inactivation, Metabolic; Inhibitors; metabolic herbicide resistance; Metabolism; Metabolites; non‐target‐site resistance; Organic chemistry; Palmer amaranth; Plant Weeds - drug effects; Plant Weeds - enzymology; Plant Weeds - metabolism; Sulfones - metabolism; Sulfones - pharmacology; tembotrione; Nebraska; enhanced metabolism; Palmer amaranth; tembotrione; cytochrome P450 enzyme; metabolic herbicide resistance; non-target-site resistance
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.4786

BACKGROUND Resistance to the 4‐hydroxyphenylpyruvate dioxygenase (HPPD)‐inhibiting herbicide tembotrione in an Amaranthus palmeri population from Nebraska (NER) has previously been confirmed to be attributable to enhanced metabolism. The objective of this study was to identify and quantify the metabolites formed in Nebraska susceptible (NES) and resistant (NER) biotypes. RESULTS NER and NES formed the same metabolites. Tembotrione metabolism in NER differed from that in NES in that resistant plants showed faster 4‐hydroxylation followed by glycosylation. The T50 value (time for 50% production of the maximum 4‐hydroxylation product) was 4.9 and 11.9 h for NER and NES, respectively. This process is typically catalyzed by cytochrome P450 enzymes. Metabolism differences between NER and NES were most prominent under 28 °C conditions and herbicide application at the four‐leaf stage. CONCLUSION Further research with the aim of identifying the gene or genes responsible for conferring metabolic resistance to HPPD inhibitors should focus on cytochrome P450s. Such research is important because non‐target‐site‐based resistance (NTSR) poses the threat of cross resistance to other chemical classes of HPPD inhibitors, other herbicide modes of action, or even unknown herbicides. © 2017 Society of Chemical Industry Non‐target site resistance to HPPD‐inhibitors in the weed Palmer amaranth poses a threat to modern agriculture. This article analyzes the mechanism of enhanced metabolism of tembotrione in metabolic‐resistant individuals.