Pflugmacher Stephan, Jung Katharina, Lundvall Linn, Neumann Stefanie, Peuthert Anja
Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany.
Environ Toxicol Chem. 2006 Sep;25(9):2381-7. doi: 10.1897/05-615r.1.
Cyanobacterial toxins have adverse effects on both terrestrial and aquatic plants. Microcystins are cyclic heptapeptides and an important group of cyanotoxins. When lake water contaminated with cyanobacterial blooms is used for spray irrigation, these toxins can come in contact with agricultural plants. During the exposure to these toxins, reactive oxygen species can form. These reactive oxygen species have a strong reactivity and are able to interact with other cellular compounds (lipids, protein, and DNA). Plants have antioxidative systems that will limit the negative effects caused by reactive oxygen species. These systems consist of enzymes, such as superoxide dismutase, catalase, and ascorbate peroxidase, and nonenzymatic substances, such as reduced glutathione or vitamins. The aim of the present study was to investigate the effects of cyanobacterial toxins (microcystins and anatoxin-a) and cyanobacterial cell-free crude extract on alfalfa (Medicago sativa) seedlings. Inhibition of germination and root growth was observed with toxin concentrations of 5.0 microg/L. Also, oxidative damage, such as lipid peroxidation, was detected after the exposure of alfalfa seedlings to the toxin. Reactive oxygen detoxifying enzymes were elevated, showing a marked response in alfalfa to oxidative stress caused by the exposure to cyanobacterial metabolites that might influence the growth and development of these plants negatively.
蓝藻毒素对陆生植物和水生植物均有不利影响。微囊藻毒素是环状七肽，也是一类重要的蓝藻毒素。当用受蓝藻水华污染的湖水进行喷灌时，这些毒素会与农作物接触。在接触这些毒素的过程中，会形成活性氧物种。这些活性氧物种具有很强的反应活性，能够与其他细胞化合物（脂质、蛋白质和DNA）相互作用。植物具有抗氧化系统，可限制活性氧物种造成的负面影响。这些系统由超氧化物歧化酶、过氧化氢酶和抗坏血酸过氧化物酶等酶以及还原型谷胱甘肽或维生素等非酶物质组成。本研究的目的是调查蓝藻毒素（微囊藻毒素和类毒素-a）以及蓝藻无细胞粗提物对苜蓿（紫花苜蓿）幼苗的影响。毒素浓度为5.0微克/升时，观察到发芽和根生长受到抑制。此外，苜蓿幼苗接触毒素后，检测到了氧化损伤，如脂质过氧化。活性氧解毒酶升高，表明苜蓿对接触蓝藻代谢产物引起的氧化应激有明显反应，这可能会对这些植物的生长发育产生负面影响。
