title: Growth and Oxidative Stress of Brittlewort (Nitella pseudoflabellata) in Response to Cesium Exposure.
abstract: The present study evaluated the impact of cesium ((133)Cs) at four concentrations (0, 0.001, 0.01, and 0.1 mg L(-1)) on growth, concentrations of chlorophyll and carotenoid pigments, and oxidative stress responses in the charophyte, Nitella pseudoflabellata, over 30 days. Oxidative stress was quantified by measuring anti-oxidant enzyme activities and H2O2 content. When compared with the control, significantly elevated activity levels of the anti-oxidative enzymes ascorbic peroxidase, catalase and guaiacol peroxidase were observed at 0.1 mg L(-1) (all p < 0.05), even though the H2O2 level was not significantly elevated. Carotenoid and chlorophyll a and b pigment levels were significantly reduced (all p < 0.05) at Cs exposures of 0.01 and 0.1 mg L(-1). Photosynthetic efficiency (i.e., Fv/Fm) was significantly reduced (p < 0.05) at Cs concentrations ≥0.001 mg L(-1). Significant reduction (p < 0.05) of plant growth (i.e., shoot length) was also observed after 1 week of exposure at Cs concentrations ≥0.001 mg L(-1). Our results suggested that Cs exposure reduced plant growth and affected plant functioning via activating the defense mechanism against oxidative stress in Nitella.
authors.affiliation: Department of Environmental Science, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570, Japan.|Department of Limnology, Faculty of Fisheries and Marine Sciences and Technology, University of Ruhuna, Matara, 81000, Sri Lanka.
authors.forename: Keerthi Sri Senartahna
authors.initials: KS
authors.lastname: Atapaththu
authors.affiliation: Department of Environmental Science, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570, Japan. mhrashid@mail.saitama-u.ac.jp.|Department of Agronomy, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh. mhrashid@mail.saitama-u.ac.jp.
authors.forename: Md Harun
authors.initials: MH
authors.lastname: Rashid
authors.affiliation: Department of Environmental Science, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Asaeda
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002586:Cesium / Q000633:toxicity*; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring; D006861:Hydrogen Peroxide / Q000378:metabolism; D044443:Nitella / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D009195:Peroxidase / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D002586:Cesium; D002338:Carotenoids; D006861:Hydrogen Peroxide; C121048:guaiacol peroxidase; D002374:Catalase; D009195:Peroxidase; D000077194:Chlorophyll A
keywords: Antioxidant enzymes; Cesium; Nitella pseudoflabellata; Oxidative stress