Reduction in germination rate and elevation of peroxidase activity in <em>Zea mays>/em> seedlings due to exposure to different microcystin analogues and toxic cell free cyanobacterial crude extract


  • S. Pflugmacher


Agricultural crop plants may come into contact with cyanobacterial toxins via spray irrigation with water contaminated with cyanobacteria/cyanobacterial toxins. Many of the bloom forming cyanobacteria are known to produce toxins amongst those the group of the microcystins, cyclic heptapeptides are the best known once. In this study the germination of Zea mays under exposure to different microcystins and cell free cyanobacterial crude extract containing microcystin-LR was investigated. The concentration used for all microcystins in this study was 5.0 μg L-1 which is well in the environmental range. The inhibition of germination was shown as well as the inhibition of root and shoot length by toxin exposure. As a sign for the generation of oxidative stress promoted by the toxins taken up, guajacol peroxidase was measured showing in most toxin exposures an elevation of peroxidase activity. This study showed that there is a potential concern a reduction in crop yield and also to human health if agriculturally important crop plants were exposed to cyanobacterial toxins via spray irrigation.