title: Bioaccumulation, subcellular, and molecular localization and damage to physiology and ultrastructure in Nymphoides peltata (Gmel.) O. Kuntze exposed to yttrium.
abstract: Bioaccumulation, subcellular distribution, and acute toxicity of yttrium (Y) were evaluated in Nymphoides peltata. The effects of Y concentrations of 1-5 mg L(-1) applied for 4 days were assessed by measuring changes in photosynthetic pigments, nutrient contents, enzymatic and non-enzymatic antioxidants, and ultrastructure. The accumulation of Y in subcellular fractions decreased in the order of cell wall > organelle > soluble fraction. Much more Y was located in cellulose and pectin than in other biomacromolecules. The content of some mineral elements (Mg, Ca, Fe, Mn, and Mo) increased in N. peltata, but there was an opposite effect for P and K. Meanwhile, ascorbate, and catalase activity decreased significantly for all Y concentrations. In contrast, peroxidase activity was induced, while initial rises in superoxide dismutase activity and glutathione content were followed by subsequent declines. Morphological symptoms of senescence, such as chlorosis and damage to chloroplasts and mitochondria, were observed even at the lowest Y concentration. Pigment content decreased as the Y concentration rose and the calculated EC50 and MPC of Y for N. peltata were 2 and 0.2 mg L(-1) after 4 days of exposure, respectively. The results showed that exogenous Y was highly available in water and that its high concentration in water bodies might produce harmful effects on aquatic organisms. N. peltata is proposed as a biomonitor for the assessment of metal pollution in aquatic ecosystems.
authors.affiliation: Institute of Plant Cell and Molecular Biology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, People's Republic of China.
authors.forename: Yongyang
authors.initials: Y
authors.lastname: Fu
authors.forename: Feifei
authors.initials: F
authors.lastname: Li
authors.forename: Ting
authors.initials: T
authors.lastname: Xu
authors.forename: Sanjuan
authors.initials: S
authors.lastname: Cai
authors.forename: Weiyue
authors.initials: W
authors.lastname: Chu
authors.forename: Han
authors.initials: H
authors.lastname: Qiu
authors.forename: Sha
authors.initials: S
authors.lastname: Sha
authors.forename: Guangyu
authors.initials: G
authors.lastname: Cheng
authors.forename: Qinsong
authors.initials: Q
authors.lastname: Xu
mesh_terms: D001205:Ascorbic Acid / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D004784:Environmental Monitoring / Q000379:methods; D005978:Glutathione / Q000378:metabolism; D019684:Magnoliopsida / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015019:Yttrium / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D002338:Carotenoids; C037184:chlorophyll b; D015019:Yttrium; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid; D000077194:Chlorophyll A