Area of Toxicology, Faculty of Pharmacy, University of Seville, Seville, Spain.
Ecotoxicol Environ Saf. 2011 Oct;74(7):1973-80. doi: 10.1016/j.ecoenv.2011.06.009. Epub 2011 Jul 1.
Toxic cyanobacteria are considered emerging world threats, being responsible for the degradation of the aquatic ecosystems. Aphanizomenon ovalisporum produces the toxin Cylindrospermopsin (CYN) being a concern in fresh water habitats. This work aims to increase our knowledge on the effects of this toxic cyanobacterium in plants by studying the alterations in growth parameters and oxidative stress status of rice (Oriza sativa) exposed to the cyanobacteria cell extracts containing CYN. Significant increases in glutathione S-transferase (GST) and glutathione peroxidase (GPx) activities were detected in the different experiments performed. The roots showed to be more sensitive than leaves regarding the enzyme activities. A reduction in the leaf tissue fresh weight was observed after 9 days of plant treatment suggesting a major physiological stress. The exposure of rice plants to a mixture of A. ovalisporum and Microcystis aeruginosa cell extracts containing CYN and microcystins including microcystin-LR, resulted in a significant increase in the GST and GPx activities, suggesting a synergistic effect of both extracts. Together these results point out the negative effects of cyanotoxins on plant growth and oxidative status, induced by A. ovalisporum cell extracts, raising also concerns in the accumulation of CYN.
有毒蓝藻被认为是对世界具有新兴威胁的生物，其会导致水生生态系统退化。鱼腥藻（Aphanizomenon ovalisporum）会产生一种名为环胞藻毒素（CYN）的毒素，这种毒素是淡水生境中的一个关注点。本研究旨在通过研究暴露于含有 CYN 的蓝藻细胞提取物的水稻（Oriza sativa）的生长参数和氧化应激状态的变化，增加我们对这种有毒蓝藻在植物中产生的影响的认识。在进行的不同实验中，均检测到谷胱甘肽 S-转移酶（GST）和谷胱甘肽过氧化物酶（GPx）活性显著增加。与叶片相比，根对酶活性的变化更为敏感。在对植物进行 9 天处理后，观察到叶片组织鲜重减少，表明出现了严重的生理胁迫。暴露于含有 CYN 和微囊藻毒素（包括微囊藻毒素-LR）的鱼腥藻和铜绿微囊藻混合细胞提取物的水稻植株中，GST 和 GPx 活性显著增加，这表明两种提取物具有协同作用。这些结果共同指出了由鱼腥藻细胞提取物引起的对植物生长和氧化状态的负面影响，同时也对 CYN 的积累提出了担忧。
