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(M/FF222) LINDANE AFFECTS DIFFERENTLY MEMBRANE PERMEABILITY, PROTEIN CONTENT AND OSMOLALITY IN TWO MACROPHYTE PLANTS. cavaleiro, lurdes1, Costa, Armando1, Gonçalves, Fernando1, Santos, Conceição 1, 1 ABSTRACT- LINDANE AFFECTS DIFFERENTLY MEMBRANE PERMEABILITY, PROTEIN CONTENT AND OSMOLALITY IN TWO MACROPHYTE PLANTS Lurdes Cavaleiro, Armando Costa, Fernando Goncalves and Conceicao Santos Department of Biology, University of Aveiro, Portugal Although lindane (g-hexachlorocyclohexane), a halogenated organic insecticide and fungicide, is being reported as an extremely toxic compound, its use still remains permitted in some countries in Europe, and in particular, in Portugal. It is important, therefore, not only to assure that farmers use this compound properly, but also to assay efficiently its impact in environment. Lindane may accumulate in plants altering their metabolism. It is under discussion if some biochemical and physiological parameters, traditionally used as senescence parameters, may be used in an efficient and rapid way to quantify the degree of toxicity of lindane in plants growing in a contaminated ecosystem. In this report, two macrophyte species were collected from three sampling stations in the margins of a lagoon at Tocha (Portugal). They were used as models to assay their behaviour in laboratory to increasing concentrations of lindane (0, 0.3, 3 and 30 mg/l). Soluble protein content of the graminea species was only affected in shoots for concentrations above 3 mg/l, while in Myriophyllum, protein concentration decreased in both roots and shoots. Osmolality was only affected by lindane in shoots of the graminea species while Myriophyllum seems to be not affected. On the other hand, it was observed a higher increase of membrane permeability (higher production of malondialdehyde) in Myriophyllum, suggesting that this plant may be more sensitive to lindane. The applicability of these physiological and biochemical parameters for rapid assays of lindane impact in plants will be discussed. Key words: macrophytes, lindan toxicity, senescence, membrane permeability |
