Response of duckweed to various concentrations of selenite
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The uptake of Se(IV) and its effects on the physiological and biochemical characteristics of duckweed (Lemna minor L.) have been studied. Duckweed plants were cultivated in controlled conditions for 7 weeks in different concentrations of Na selenite: 0.5, 1, 2, 5 (exposed 42 days) and 10 mg Se L−1 (survived 7–21 days). The addition of 1 mg Se L−1 did not negatively affect photochemical efficiency whilst respiratory potential increased in weeks 2–4 compared to control. The addition of 1 mg Se(IV) L−1 increased the amount of chlorophyll a in weeks 3 and 4 and the amount of carotenoids in weeks 1, 3 and 5. Concentrations of 2 and 5 mg Se L−1 negatively affected photochemical efficiency in weeks 3 and 4, and increased respiratory potential in comparison to the control in weeks 1–4, whilst beyond week 4, the respiratory potential decreased. Plants exposed to the highest concentration of Se(IV) had to be replaced twice during the experiment because they were dying. That was reflected in photochemical efficiency as well as in respiratory potential, which decreased in time. The content of Se in duckweed increased with the increasing concentration of Se: plants growing in 0.5 mg Se L−1 contained 0.9 mg Se g−1 DM and plants exposed to 5 mg Se L−1 contained 5.8 mg Se g−1 DM. The group of plants exposed to 10 mg Se L−1 for 21 days contained 19.5 mg Se g−1 DM. Our study revealed that duckweed absorbed high amount of Se(IV) from the water.
KeywordsDuckweed Selenite Photochemical efficiency Respiratory potential HG-AFS
The authors are grateful to Terry Troy Jackson for a critical reading of the manuscript. This research was financed by the Ministry of Higher Education, Science and Technology of the Republic of Slovenia through the program ‘Young researchers’ (32059), ‘Biology of plants’ (P1-0212) and the projects J4-2041 and program P1-0143.
- Carvalho KM, Martin DF (2001) Removal of aqueous selenium by four aquatic plants. J Aquat Plant Manage 39:33–36Google Scholar
- Council Directive 2004/C 50/01 (70/524/EEC), List of the authorised additives in feedingstuffs published in application of Article 9 t (b) of Council Directive 70/524/EEC concerning additives in feedingstuffsGoogle Scholar
- Lichtenthaler HK, Buschmann C (2001a) Extraction of photosynthetic tissues: chlorophylls and carotenoids. In: Wrolstad RE, Acree TE, Decker EA (eds) Current protocols in food analytical chemistry. Wiley, New York, pp F.4.2.1–4.2.6Google Scholar
- Lichtenthaler HK, Buschmann C (2001b) Chlorophylls and carotenoids: measurement and characterization by UV-VIS. In: Wrolstad RE, Acree TE, Decker EA (eds) Current protocols in food analytical chemistry. John Wiley & Sons Inc, New York, pp F.4.2.1–4.2.6Google Scholar
- OECD, ISO 20079. Guideline for Testing of Chemicals, No. 221, Lemna sp. Growth Inhibition Test (2006)Google Scholar
- Packard TT (1971) The measurement of respiratory electron-transport activity in marine phytoplankton. J Mar Res 29:235–243Google Scholar
- Slovenian Regulations the Sanitary Suitability, UL RS, no. 33/01. Uradni list 65 (2002)Google Scholar