Centro Interdisciplinar de Investigação Marinha e Ambiental, CIIMAR/CIMAR, Rua dos Bragas 289, 4050-123, Porto, Portugal.
Ecotoxicology. 2014 Mar;23(2):107-21. doi: 10.1007/s10646-013-1156-8. Epub 2013 Dec 10.
Microcystin-leucine and arginine (microcystin-LR) is a cyanotoxin produced by cyanobacteria like Microcystis aeruginosa, and it's considered a threat to water quality, agriculture, and human health. Rice (Oryza sativa) is a plant of great importance in human food consumption and economy, with extensive use around the world. It is therefore important to assess the possible effects of using water contaminated with microcystin-LR to irrigate rice crops, in order to ensure a safe, high quality product to consumers. In this study, 12 and 20-day-old plants were exposed during 2 or 7 days to a M. aeruginosa extract containing environmentally relevant microcystin-LR concentrations, 0.26-78 μg/L. Fresh and dry weight of roots and leaves, chlorophyll fluorescence, glutathione S-transferase and glutathione peroxidase activities, and protein identification by mass spectrometry through two-dimensional gel electrophoresis from root and leaf tissues, were evaluated in order to gauge the plant's physiological condition and biochemical response after toxin exposure. Results obtained from plant biomass, chlorophyll fluorescence, and enzyme activity assays showed no significant differences between control and treatment groups. However, proteomics data indicates that plants respond to M. aeruginosa extract containing environmentally relevant microcystin-LR concentrations by changing their metabolism, responding differently to different toxin concentrations. Biological processes most affected were related to protein folding and stress response, protein biosynthesis, cell signalling and gene expression regulation, and energy and carbohydrate metabolism which may denote a toxic effect induced by M. aeruginosa extract and microcystin-LR. The implications of the metabolic alterations in plant physiology and growth require further elucidation.
微囊藻氨酸-亮氨酸和精氨酸（微囊藻氨酸-LR）是由铜绿微囊藻等蓝藻产生的一种蓝藻毒素，被认为是对水质、农业和人类健康的威胁。水稻（Oryza sativa）是人类食用和经济的重要作物，在全球范围内广泛种植。因此，评估使用含有微囊藻氨酸-LR 的水灌溉水稻作物的可能影响非常重要，以确保向消费者提供安全、高质量的产品。在这项研究中，12 天和 20 天的水稻幼苗分别在含有环境相关浓度（0.26-78μg/L）微囊藻氨酸-LR 的铜绿微囊藻提取物中暴露 2 或 7 天。评估了新鲜和干重的根和叶、叶绿素荧光、谷胱甘肽 S-转移酶和谷胱甘肽过氧化物酶活性以及通过根和叶组织的二维凝胶电泳进行的质谱蛋白质鉴定，以评估植物在毒素暴露后的生理状况和生化反应。从植物生物量、叶绿素荧光和酶活性测定结果来看，对照组和处理组之间没有显著差异。然而，蛋白质组学数据表明，植物对含有环境相关浓度微囊藻氨酸-LR 的铜绿微囊藻提取物作出反应，改变了它们的新陈代谢，对不同的毒素浓度有不同的反应。受影响最大的生物过程与蛋白质折叠和应激反应、蛋白质生物合成、细胞信号和基因表达调控以及能量和碳水化合物代谢有关，这可能表示铜绿微囊藻提取物和微囊藻氨酸-LR 诱导的毒性作用。这些代谢变化对植物生理学和生长的影响需要进一步阐明。
