title: Bidens pilosa L. exhibits high sensitivity to coumarin in comparison with three other weed species.
abstract: Nine natural plant compounds were screened for phytotoxicity to Bidens pilosa L. a troublesome weed in field and plantation crops. The sensitivity of three other weed species to coumarin, the most active identified compound, was also evaluated. Coumarin, at a concentration of 500 microM, had little effect on germination and growth of Senna obtusifolia L., Euphorbia heterophylla L., and Ipomoea grandifolia L. when compared with its effects on B. pilosa L. In a concentration range of 10-100 microM, coumarin caused a dose-dependent inhibition of germination and growth of B. pilosa L. The measurements of some parameters of energy metabolism revealed that coumarin-treated root tissues exhibited characteristics of seedlings in an earlier stage of growth, including higher respiratory activity and higher activities of alcohol dehydrogenase and lipoxygenase. These results suggest that coumarin inhibition of germination and growth of B. pilosa L. was not a consequence of an impairment of energy metabolism. Rather, it seems to act as a cytostatic agent, retarding germination. At concentrations above 50 microM, coumarin increased lipoxygenase activity and the level of conjugated dienes of root extracts, suggesting that it may induce oxidative stress in seedling roots.
authors.affiliation: Laboratory of Biological Oxidations, Department of Biochemistry, University of Maringá, 87020900 Maringá, Brazil.
authors.forename: Erica Marusa
authors.initials: EM
authors.lastname: Pergo
authors.forename: Denise
authors.initials: D
authors.lastname: Abrahim
authors.forename: Patrícia Cristina
authors.initials: PC
authors.lastname: Soares da Silva
authors.forename: Kátia Aparecida
authors.initials: KA
authors.lastname: Kern
authors.forename: Lucas Jonatas
authors.initials: LJ
authors.lastname: Da Silva
authors.forename: Elemar
authors.initials: E
authors.lastname: Voll
authors.forename: Emy Luiza
authors.initials: EL
authors.lastname: Ishii-Iwamoto
mesh_terms: D031176:Bidens / Q000187:drug effects* / Q000502:physiology; D003374:Coumarins / Q000494:pharmacology*; D018525:Germination; D013045:Species Specificity
chemical_list: D003374:Coumarins; C030123:coumarin