title: Bio-accumulation and toxicity of lead (Pb) in Lemna gibba L (duckweed).
abstract: The vascular aquatic plant Lemna gibba (duckweed) was exposed during seven days to lead (Pb) at concentrations ranging from 50 to 300 mg/L in a greenhouse with controlled photoperiod and temperature. The effects of Pb on growth of Lemna gibba were examined during 13 days in the same experimental design. The maximum accumulation of lead by Lemna gibba occurs during the third day in the 50 mg/L test, and at the sixth day, lead in all test concentrations produces approximately a 100% inhibitory effect on duckweed growth. In all tests, the maximum relative growth rates were achieved on the third day and then, the toxicity effects were: 59.3% total soluble starch reduction; 94.7% total soluble proteins reduction; 246% increase in total soluble amino acids; 50% increase in total soluble sugars and an 18.2% increase in total phenols. This experiment showed that the transfers of Pb from nutritive solution to plants were fast. Nevertheless, Pb produced toxic effects on Lemna gibba; however duckweed was able to remove Pb at the experimental concentrations used.
authors.affiliation: Department of Hydrobiology, Universidad Autonoma Metropolitana-Iztapalapa, Iztapalapa, Mexico.
authors.forename: Alma S
authors.initials: AS
authors.lastname: Sobrino
authors.forename: Maria G
authors.initials: MG
authors.lastname: Miranda
authors.forename: Carlos
authors.initials: C
authors.lastname: Alvarez
authors.forename: Agustin
authors.initials: A
authors.lastname: Quiroz
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000378:metabolism; D029064:Araceae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D050260:Carbohydrate Metabolism / Q000187:drug effects; D002241:Carbohydrates / Q000032:analysis; D006128:Growth / Q000187:drug effects; D007854:Lead / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D010636:Phenols / Q000032:analysis / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis / Q000378:metabolism; D013213:Starch / Q000032:analysis / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D018508:Water Purification / Q000379:methods
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D010636:Phenols; D010940:Plant Proteins; D014874:Water Pollutants, Chemical; D007854:Lead; C029891:lead chloride; D013213:Starch