Toxicity Of The Herbicide Glyphosate On M.Aeruginosa And M.Viridis

Aquatic ecosystem pollutions are mainly resulted from extensively use of herbicides in recent years. Among them, herbicide glyphosate used in conjunction with genetically modified crops has been the champion of its sales due to the global promotion of genetically modified crops. The outbreaks of algal blooms have received worldwide attention. The key reason is that the imbalance of aquatic ecosystems, causing algae (especially cyanobacteria) overgrowth. However, few studies have focused on the possible link between glyphosate at ambient concentration levels and the outbreaks of algae blooms. Herbicide glyphosate has been used extensively in many countries in agriculture for weed control. It can be transported to the aquatic environment and may cause adverse effects on aquatic lives. In this paper, Microcystis aeruginosa and Microcystis viridis act as effect receptors exposed to glyphosate, we use growth curve to characterize its impact on Microcystis aeruginosa and Microcystis viridis growth at different times in different concentration gradient. Then further we determine their protein and algae toxin levels change at different concentrations in different exposure time, and this process of oxidative damage were analyzed to explore the impact on the two cyanobacteria of glyphosate.The results of the test for toxicity of glyphosate on M. aeruginosa showed that glyphosate could increase the concentration of the malondialdehyde (MDA), enhance the activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) at 24h. Glyphosate could induced apoptosis of M. aeruginosa and triggered toxin release in M. aeruginosa. The results of the test for toxicity of glyphosate on M.viridis showed that low concentration of glyphosate could enhance the activity of SOD. decrease the concentration of the MDA at 24h. And low concentration of glyphosate could not induced apoptosis of M.viridis, but could promote the growth of M.viridis.The results are helpful in understanding the toxic effects of commonly used herbicide on cyanobacteria, which is important for environmental assessment and protection. It is also helpful for guiding the application of this kind of herbicide in agricultural settings.