title: Mesotrione: a new selective herbicide for use in maize.
abstract: Mesotrione is a new herbicide being developed for the selective pre- and post-emergence control of a wide range of broad-leaved and grass weeds in maize (Zea mays). It is a member of the benzoylcyclohexane-1,3-dione family of herbicides, which are chemically derived from a natural phytotoxin obtained from the Californian bottlebrush plant, Callistemon citrinus. The compound acts by competitive inhibition of the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD), a component of the biochemical pathway that converts tyrosine to plastoquinone and alpha-tocopherol. Mesotrione is an extremely potent inhibitor of HPPD from Arabidopsis thaliana, with a Ki value of c 6-18 pM. It is rapidly taken up by weed species following foliar application, and is distributed within the plants by both acropetal and basipetal movement. Maize is tolerant to mesotrione as a consequence of selective metabolism by the crop plant. Slower uptake of mesotrione, relative to susceptible weed species, may also contribute to its utility as a selective herbicide for use in maize.
authors.affiliation: Zeneca Agrochemicals, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6ET, UK. glynn.g.mitchell@aguk.zeneca.com
authors.forename: G
authors.initials: G
authors.lastname: Mitchell
authors.forename: D W
authors.initials: DW
authors.lastname: Bartlett
authors.forename: T E
authors.initials: TE
authors.lastname: Fraser
authors.forename: T R
authors.initials: TR
authors.lastname: Hawkes
authors.forename: D C
authors.initials: DC
authors.lastname: Holt
authors.forename: J K
authors.initials: JK
authors.lastname: Townson
authors.forename: R A
authors.initials: RA
authors.lastname: Wichert
mesh_terms: D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000037:antagonists & inhibitors*; D003512:Cyclohexanones / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D006540:Herbicides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D015394:Molecular Structure; D018515:Plant Leaves / Q000378:metabolism; D010944:Plants / Q000187:drug effects* / Q000378:metabolism; D013329:Structure-Activity Relationship; D003313:Zea mays / Q000378:metabolism*
chemical_list: D003512:Cyclohexanones; D004791:Enzyme Inhibitors; D006540:Herbicides; C432907:mesotrione; D015111:4-Hydroxyphenylpyruvate Dioxygenase