title: The effects of dopamine on root growth and enzyme activity in soybean seedlings.
abstract: In the present study, we investigated the effects of dopamine, an allelochemical exuded from the velvetbean (Mucuna pruriens L DC. var utilis), on the growth and cell viability of soybean (Glycine max L. Merrill) roots. We analyzed the effects of dopamine on superoxide dismutase, phenylalanine ammonia-lyase and cell wall-bound peroxidase activities as well as its effects on lignin contents in the roots. Three-day-old seedlings were cultivated in half-strength Hoagland nutrient solution (pH 6.0), without or with 0.25 to 1.0 mM dopamine, in a growth chamber (25°C, 12L:12D photoperiod, irradiance of 280 μmol m(-2) s(-1)) for 24 h. In general, the length, fresh weight and dry weight of roots, cell viability, PAL and POD activities decreased, while SOD activities increased after dopamine treatment. The content of lignin was not altered. The data demonstrate the susceptibility of soybean to dopamine and reinforce the role of this catecholamine as a strong allelochemical. The results also suggest that dopamine-induced inhibition in soybean roots is not related to the production of lignin, but may be related to damage caused by reactive oxygen species.
authors.affiliation: Laboratory of Plant Biochemistry; Department of Biochemistry; State University of Maringá; Maringá, PR Brazil.
authors.forename: Bruno Boni
authors.initials: BB
authors.lastname: Guidotti
authors.forename: Bruno Ribeiro
authors.initials: BR
authors.lastname: Gomes
authors.forename: Rita de Cássia
authors.initials: Rde C
authors.lastname: Siqueira-Soares
authors.forename: Anderson Ricardo
authors.initials: AR
authors.lastname: Soares
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Ferrarese-Filho
mesh_terms: D018533:Biomass; D002470:Cell Survival / Q000187:drug effects; D004298:Dopamine / Q000494:pharmacology*; D008031:Lignin / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development*; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D013025:Glycine max / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development*
chemical_list: D008031:Lignin; D004298:Dopamine
keywords: allelopathy; dopamine; lignin; peroxidase; phenolic compounds; phenylalanine ammonia-lyase; root growth; soybean; superoxide dismutase