title: Absorption, translocation and metabolism of metamitron in Chenopodium album.
abstract: BACKGROUND
  In recent years, common lambsquarters (Chenopodium album L.) populations from sugar beet fields in different European countries have responded as resistant to the as-triazinone metamitron. The populations have been found to have the same D1 point mutation as known for atrazine-resistant biotypes (Ser264 to Gly). However, pot experiments revealed that metamitron resistance is not as clear-cut as observed with triazine resistance in the past. The objectives of this study were to clarify the absorption, translocation and metabolic fate of metamitron in C. album.
  
  
  RESULTS
  Root absorption and foliar absorption experiments showed minor differences in absorption, translocation and metabolism of metamitron between the susceptible and resistant C. album populations. A rapid metabolism in the C. album populations was observed when metamitron was absorbed by the roots. The primary products of metamitron metabolism were identified as deamino-metamitron and metamitron-N-glucoside. PABA, known to inhibit the deamination of metribuzin, did not alter the metabolism of metamitron, and nor did the cytochrome P450 inhibitor PBO. However, inhibition of metamitron metabolism in the presence of the cytochrome P450 inhibitor ABT was demonstrated.
  
  
  CONCLUSIONS
  Metamitron metabolism in C. album may act as a basic tolerance mechanism, which can be important in circumstances favouring this degradation pathway.
authors.affiliation: Weed Science Unit, Faculty of Bioscience Engineering, Department of Plant Production, Ghent University, Gent, Belgium. jonas.aper@ugent.be
authors.forename: Jonas
authors.initials: J
authors.lastname: Aper
authors.forename: Els
authors.initials: E
authors.lastname: Mechant
authors.forename: Baruch
authors.initials: B
authors.lastname: Rubin
authors.forename: Arne
authors.initials: A
authors.lastname: Heyerick
authors.forename: Gert
authors.initials: G
authors.lastname: Callebaut
authors.forename: Sven
authors.initials: S
authors.lastname: Mangelinckx
authors.forename: Dieter
authors.initials: D
authors.lastname: Deforce
authors.forename: Norbert
authors.initials: N
authors.lastname: De Kimpe
authors.forename: Robert
authors.initials: R
authors.lastname: Bulcke
authors.forename: Dirk
authors.initials: D
authors.lastname: Reheul
mesh_terms: D000327:Adsorption; D027463:Chenopodium album / Q000378:metabolism*; D053209:Herbicide Resistance; D006540:Herbicides / Q000378:metabolism*; D010848:Picolinic Acids; D010882:Piperonyl Butoxide; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D014227:Triazines / Q000378:metabolism*; D014230:Triazoles
chemical_list: D006540:Herbicides; D010848:Picolinic Acids; D014227:Triazines; D014230:Triazoles; C571995:picolinic acid t-butyl amide; C033020:1-aminobenzotriazole; C047758:metamitron; D010882:Piperonyl Butoxide