title: Transport of ferrocyanide by two eucalypt species and sorghum.
abstract: The wastes from some industrial processes and the tailings from gold mining contain elevated concentrations of cyanide, which reacts with iron in the media to form iron cyanide complexes. This research examined the transport and possible metabolism of ferrocyanide by two native Australian trees, blue mallee and sugar gum, and by sorghum. Hydroponic studies using 15N-labeled ferrocyanide showed that both tree species transported ferrocyanide into roots and displayed significant increases in 15N enrichment and concentration with no evidence of phytotoxicity. A subsequent experiment with blue mallee and membrane-transport inhibitors showed that 15N enrichment was significantly inhibited in the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone, suggesting that ferrocyanide uptake is mediated partly by H+ -symporters. A study of the time dependence of 15N translocation showed a rapid equilibration of 15N from ferrocyanide in the root of blue mallee, accompanied by a slow increase in shoot 15N, suggestive of the metabolism of ferrocyanide in plant roots. A similar experiment with sorghum showed a more rapid translocation of 15N, suggesting that the transport and/or metabolism of ferrocyanide by roots of this species may differ. The results offer additional incentive for the use of these species as vegetative cover over cyanidation wastes and for cyanide phytoremediation.
authors.affiliation: Department of Plant Biology, Southern Illinois University Carbondale, Carbondale, IL 62901-6509, USA. sebbs@plant.siu.edu
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Ebbs
authors.forename: Robert C
authors.initials: RC
authors.lastname: Piccinin
authors.forename: Jason Q D
authors.initials: JQ
authors.lastname: Goodger
authors.forename: Spas D
authors.initials: SD
authors.lastname: Kolev
authors.forename: Ian E
authors.initials: IE
authors.lastname: Woodrow
authors.forename: Alan J M
authors.initials: AJ
authors.lastname: Baker
mesh_terms: D001673:Biodegradation, Environmental; D001692:Biological Transport / Q000502:physiology; D005052:Eucalyptus / Q000378:metabolism*; D005295:Ferrocyanides / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D018547:Plant Stems / Q000737:chemistry / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism; D045868:Sorghum / Q000378:metabolism*; D013045:Species Specificity; D013997:Time Factors
chemical_list: D005295:Ferrocyanides; D012989:Soil Pollutants; C020354:hexacyanoferrate II