title: Effect of haloxyfop and cerulenin on de novo biosynthesis of lipids in roots of wheat and maize.
abstract: The study examines the effects of haloxyfop (herbicide) and cerulenin (antibiotic) on de novo biosynthesis of fatty acids and complex lipids in roots of two sensitive species: wheat and maize. Seedlings were grown in hydroponic cultures with addition of [1-(14)C]acetate (control) and [1-(14)C]acetate together with one of the tested substances. Neither haloxyfop nor cerulenin prevented the uptake of [1-(14)C]acetate by the roots of tested species. In contrast, a strong inhibition of de novo biosynthesis of fatty acids was observed after a 4-h treatment. This phenomenon, however, tended to disappear with treatment time. After a 24-h incubation, the amount of radioactivity in de novo biosynthesized fatty acids in 1-cm-long root tips was up to three times higher than in the untreated control. In the "rest of roots", restoration of fatty acid biosynthesis capacity was less pronounced. Besides the effect on fatty acid biosynthesis, both tested inhibitors strongly suppressed the de novo biosynthesis of non-fatty acid-containing lipids. Analyses of radioactivity in individual lipid classes showed that after a 4-h treatment with haloxyfop or cerulenin the biosynthesis of most of the lipid classes was inhibited, although not to the same extent. After a 24-h treatment, an inhibition of de novo biosynthesis of some of the lipids was still observable, whereas the biosynthesis of others, especially phosphatidylethanolamine and phosphatidic acid, was strongly up-regulated. Contrary to the mainstream view that inhibition of fatty acid biosynthesis is the cause of haloxyfop and cerulenin phytotoxicity, the obtained results suggest multidirectional effects of both inhibitors.
authors.affiliation: Institute of Biology, University of Natural Sciences and Humanities, Siedlce, Poland. wbanas@uph.edu.pl
authors.forename: Walentyna
authors.initials: W
authors.lastname: Banaś
authors.forename: Tomasz
authors.initials: T
authors.lastname: Furmanek
authors.forename: Antoni
authors.initials: A
authors.lastname: Banaś
mesh_terms: D002250:Carbon Radioisotopes; D002569:Cerulenin / Q000494:pharmacology; D005227:Fatty Acids / Q000096:biosynthesis*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D036226:Seedlings; D014908:Triticum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D005227:Fatty Acids; D011725:Pyridines; D002569:Cerulenin; C054176:haloxyfop