Academic Journals Database
Disseminating quality controlled scientific knowledge

Stress-physiological reactions of the green alga Scenedesmus opoliensis to water pollution with herbicides

ADD TO MY LIST
 
Author(s): Laszlo FODORPATAKI | Csaba BARTHA | Zsolt Gyula KERESZTES

Journal: Analele Universitatii din Oradea, Fascicula Biologie
ISSN 1224-5119

Volume: TOM XVI;
Issue: 1;
Start page: 51;
Date: 2009;
VIEW PDF   PDF DOWNLOAD PDF   Download PDF Original page

Keywords: algal biomass | antioxidants | environmental stress | lipid peroxidation | molecular indicators | water pollution

ABSTRACT
The freshwater green alga Scenedesmus opoliensis proves to be a suitable bioindicator of water pollution with different herbicides. One of the best molecular markers of stress condition imposed by herbicides is overproduction of malondialdehyde resulting from lipid peroxidation in the damaged membranes. Methylviologen, a largely used pre-emergence herbicide which generates reactive oxygen species in the illuminated chloroplasts, triggers the accumulation of ascorbic acid and enhances the enzymatic activity of catalase, both of these substances being involved in the antioxidative protection of algal cells. Diuron, a herbicide that inhibits photosynthetic electron transport on the acceptor side of photosystem II, causes a decline in oxygen production and in biomass accumulation of algae. Glufosinate induces accumulation of toxic ammonia and leads to enhanced net oxygen production, associated with a low rate of carbon assimilation. Long-term exposure to micromolar concentrations of herbicides results in significant changes in the rate of cell division, in hotosynthetic parameters and in the intensity of antioxidative defense. A proper bioindication of toxic effects of herbicides on algae requires a selected combination of different physiological and biochemical parameters which reflect the degree of stress exerted on living organisms by water pollution with xenobiotic organic compounds.
Why do you need a reservation system?      Affiliate Program