Bittencourt-Oliveira M C, Hereman T C, Cordeiro-Araújo M K, Macedo-Silva I, Dias C T, Sasaki F F C, Moura A N
Department of Biological Sciences, Luiz de Queiroz College of Agriculture, University of São Paulo - USP, Piracicaba, SP, Brazil.
Graduating Program on Biological Sciences, São Paulo State University - UNESP, Rio Claro, SP, Brazil.
Braz J Biol. 2014 Nov;74(4):753-60. doi: 10.1590/1519-6984.06213. Epub 2014 Nov 1.
Microcystins (MC) are the most studied toxins of cyanobacteria since they are widely distributed and account for several cases of human and animal poisoning, being potent inhibitors of the serine/threonine protein phosphatases 1 (PP1) and 2A (PP2A). The phosphatases PP1 and PP2A are also present in plants, which may also suffer adverse effects due to the inhibition of these enzymes. In aquatic plants, biomass reduction is usually observed after absorption of cyanotoxins, which can bioaccumulate in its tissues. In terrestrial plants, the effects caused by microcystins vary from inhibition to stimulation as the individuals develop from seedling to adult, and include reduction of protein phosphatases 1 and 2A, oxidative stress, decreased photosynthetic activity and even cell apoptosis, as well as bioaccumulation in plant tissues. Thus, the irrigation of crop plants by water contaminated with microcystins is not only an economic problem but becomes a public health issue because of the possibility of food contamination, and this route of exposure requires careful monitoring by the responsible authorities.
微囊藻毒素（MC）是研究最多的蓝藻毒素，因为它们分布广泛，导致了多起人类和动物中毒事件，是丝氨酸/苏氨酸蛋白磷酸酶1（PP1）和2A（PP2A）的强效抑制剂。PP1和PP2A磷酸酶也存在于植物中，这些酶的抑制也可能使植物受到不利影响。在水生植物中，吸收蓝藻毒素后通常会观察到生物量减少，蓝藻毒素会在其组织中生物累积。在陆生植物中，随着个体从幼苗发育到成年，微囊藻毒素引起的影响从抑制到刺激各不相同，包括PP1和PP2A减少、氧化应激、光合活性降低甚至细胞凋亡，以及在植物组织中的生物累积。因此，用受微囊藻毒素污染的水灌溉农作物不仅是一个经济问题，而且由于存在食品污染的可能性，还成为一个公共卫生问题，这种暴露途径需要相关部门进行仔细监测。
