title: Cd tolerance and accumulation in the aquatic macrophyte, Chara australis: potential use for charophytes in phytoremediation.
abstract: We investigated the potential use of the alga Chara australis (R. Br.) forphytore mediation of Cd-contaminated sediments in aquatic systems. Chara tolerated up to 20 mg added Cd (kg soil)⁻¹ in laboratory culture. Chlorophyll a and b levels were not affected even at Cd concentrations that suppressed growth. Levels of glutathione were suppressed at 2-35 mg added Cd (kg soil)⁻¹ to 200-350 nmol GSH (g DW)⁻¹, while control levels were 660 nmol GSH (g DW)⁻¹). Histochemical studies showed Cd occurred throughout cell walls and cytoplasm in plants grown in 5-20 mg Cd (kg soil)⁻¹. Quantification using ICP-MS showed the maximum concentration in shoots was 72 mg Cd (kg DW)⁻¹ at 35 mg added Cd (kg soil)⁻¹, while the maximum in rhizoids was 116 mg Cd (kg DW)⁻¹ at 25 mg added Cd (kg soil)⁻¹. The bioconcentration factor (BCF, concentration in plant/concentration in soil) exceeded 1.0, the critical value for hyperaccumulators, for shoots exposed to 35 mg Cd (kg soil)⁻¹ and rhizoids exposed to ≥25 mg Cd (kg soil)⁻¹. Translocation factors (TF, shoot concentration/rhizoid concentration) did not exceed 1.0 for any treatment. While Chara cannot be considered a hyperaccumulator, it shows promise for use in phytoremediation efforts.
authors.affiliation: Department of Biological SciencesUniversity at Buffalo, State University of New York at Buffalo, New York 14260, USA.
authors.forename: Bernadette L
authors.initials: BL
authors.lastname: Clabeaux
authors.forename: Divina A G
authors.initials: DA
authors.lastname: Navarro
authors.forename: Diana S
authors.initials: DS
authors.lastname: Aga
authors.forename: Mary A
authors.initials: MA
authors.lastname: Bisson
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D059001:Aquatic Organisms / Q000187:drug effects* / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D001692:Biological Transport / Q000187:drug effects; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity*; D044784:Chara / Q000187:drug effects* / Q000254:growth & development; D002734:Chlorophyll / Q000032:analysis; D004784:Environmental Monitoring; D005978:Glutathione / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D012987:Soil / Q000737:chemistry
chemical_list: D012987:Soil; D002104:Cadmium; D002734:Chlorophyll; D005978:Glutathione