Doi:10.1016/j.jhazmat.2009.07.096

Journal of Hazardous Materials 172 (2009) 854–861 Se(IV) phytotoxicity for monocotyledonae cereals (Hordeum vulgare L., Triticumaestivum L.) and dicotyledonae crops (Sinapis alba L., Brassica napus L.) Marianna Molnárová, Agáta Fargaˇsová Department of Ecosozology and Physiotactics, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina B2, SK-842 15 Bratislava, Slovak Republic The phytotoxicity of Se(IV) was determined through root and shoot growth inhibition, biomass (dry (DM), fresh (FM)) production, water content, photosynthetic pigment (chlorophyll a, chlorophyll b and carotenoids) levels and Se accumulation in the roots and shoots. The sensitivities of monocotyledonae (Hordeum vulgare, Triticum aestivum) and dicotyledonae plants (Sinapis alba, Brassica napus) were also compared. Except for H. vulgare, Se(IV) inhibited root growth more than shoot growth. As for biomassproduction, Se reduced both FM and DM of all studied plants’ roots. Although in shoots FM was decreased with increased Se concentration, DM was reduced only in monocotyledonae plants (H. vulgare, T. aes- tivum). No significant differences between roots and shoots were confirmed for the DM/FM relationship, except for S. alba seedlings. In all of the tested plants, except for B. napus, chlorophyll b was the strongest reduced pigment. Accumulation of Se was higher in the roots than in the shoots of all studied plants. Sele- nium concentration in the roots was at least 3-times higher than that in controls. Se(IV) accumulation in the shoots was not significantly different from that in controls. The exception was confirmed only for B.
napus (87 mg Se(IV) l−1) and T. aestivum (36 mg Se(IV) l−1).
2009 Elsevier B.V. All rights reserved.
1. Introduction
non-biological techniques and biological treatment options havebeen described, e.g., Se anion exchange, sorption, immobilization, The importance of selenium (Se) as a naturally occurring poten- tially toxic trace element in various natural and human-affected The essentiality of selenium for animals and bacteria is fre- environments has received considerable publicity and scientific quently discussed; however, its physiological role in plants still attention during the past century naturally occur- remains controversial differ in their ability to accumu- ring, Se accounts for a large proportion of contamination problems late Se in their tissues trace amounts of selenium are (existing and potential). A number of anthropogenic activities also tolerable, Se is more toxic at higher concentrations than arsenic or generate Se-laden wastes, including petroleum refining, mining, mercury ow Se concentrations inhibit lipid peroxidation in fossil fuel combustion, and a wide variety of industrial processes.
Lolium perenne, and this decrease coincides with growth enhance- Consequently, one primary focus of researchers is the consideration ment. At high concentrations, Se acts as a prooxidant and leads to of different methods for Se removal, immobilization in soil/water drastic reductions in yield In non-tolerant plant species, Se systems or accumulation in biota. Understanding of the possi- compounds may impair germination and growth and lead to chloro- ble oxidation and coordination states under various conditions is sis Kabata-Pendias and Pendias that increasing essential since these factors control Se mobility, bioavailability, and concentrations of selenium reduce the absorption of heavy met- toxicity wo selenium inorganic forms naturally occur most als (mainly Mn, Zn, Cu, Fe and Cd). The reduction of heavy metal often: Se(IV) and Se(VI). While algae prefer selenium in the form absorption depends on the ratios of Se and individual element.
of selenites, terrestrial plants favor selenates. Se(IV) can be harm- Most of the toxic effects of Se are related to its chemical similari- ful to plants even if the concentration is quite low Soluble, ties to sulphur. Most enzymes involved in sulphur metabolism also toxic oxyanionic forms, including selenate (SeO 2− catalyze analogous reactions with the corresponding Se substrates , Se4+), comprise most of the Se found in agricultural previously cited literature indicates a long-standing drainage waters, as well as in industrial water streams any appreciation of the need for control of Se valence and coordinationin the environment, relatively little direct information regarding Sephytotoxic effects is available. In view of the aforementioned con- siderations, a study of Se(IV) phytotoxicity to geographically widely Corresponding author. Tel.: +421 2 602 96 575; fax: +421 2 602 96 704.
E-mail addresses: (M. Molnárová), raised agricultural plants, represented by monocotyledonae cereals like Hordeum vulgare L. and Triticum aestivum L. and the dicotyle- 0304-3894/$ – see front matter 2009 Elsevier B.V. All rights reserved.

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