title: Corn poppy (Papaver rhoeas) cross-resistance to ALS-inhibiting herbicides.
abstract: BACKGROUND
  Papaver rhoeas (L.) has evolved resistance to tribenuron in winter wheat fields in northern Greece owing to multiple Pro(197) substitutions. Therefore, the cross-resistance pattern to other sulfonylurea and non-sulfonylurea ALS-inhibiting herbicides of the tribenuron resistant (R) and susceptible (S) corn poppy populations was studied by using whole-plant trials and in vitro ALS catalytic activity assays.
  
  
  RESULTS
  The whole-plant trials revealed that tribenuron R populations were also cross-resistant to sulfonylureas mesosulfuron + iodosulfuron, chlorsulfuron and triasulfuron. The whole-plant resistance factors (RFs) calculated for pyrithiobac, imazamox and florasulam ranged from 12.4 to > 88, from 1.5 to 28.3 and from 5.6 to 25.4, respectively, and were lower than the respective tribenuron RF values (137 to > 2400). The ALS activity assay showed higher resistance of the ALS enzyme to sulfonylurea herbicides (tribenuron > chlorsulfuron) and lower resistance to non-sulfonylurea ALS-inhibiting herbicides (pyrithiobac > florasulam ≈ imazamox).
  
  
  CONCLUSIONS
  These findings indicate that Pro(197) substitution by Ala, Ser, Arg or Thr in corn poppy results in a less sensitive ALS enzyme to sulfonylurea herbicides than to other ALS-inhibiting herbicides. The continued use of sulfonylurea herbicides led to cross-resistance to all ALS-inhibiting herbicides, making their use impossible in corn poppy resistance management programmes.
authors.affiliation: Laboratory of Agronomy, School of Agriculture, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Nikolaos S
authors.initials: NS
authors.lastname: Kaloumenos
authors.forename: Vasiliki N
authors.initials: VN
authors.lastname: Adamouli
authors.forename: Christos A
authors.initials: CA
authors.lastname: Dordas
authors.forename: Ilias G
authors.initials: IG
authors.lastname: Eleftherohorinos
mesh_terms: D000095:Acetolactate Synthase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D053209:Herbicide Resistance; D006540:Herbicides / Q000494:pharmacology*; D028101:Papaveraceae / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D010940:Plant Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D013453:Sulfonylurea Compounds / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D006540:Herbicides; D010940:Plant Proteins; D013449:Sulfonamides; D013453:Sulfonylurea Compounds; D000095:Acetolactate Synthase