Malaissi Luciano, Vaccarini Cristian Adrián, Hernández Marcelo Paulo, Ruscitti Marcela, Arango Cecilia, Busquets Federico, Arambarri Ana María, Giannuzzi Leda, Andrinolo Darío, Sedan Daniela
Center for Environmental Research (CIM), National Council for Scientific and Technical Research (CONICET), National University of La Plata (UNLP), La Plata 1900, Buenos Aires, Argentina.
Area of Toxicology, School of Exact Sciences, National University of La Plata (UNLP), La Plata 1900, Buenos Aires, Argentina.
Toxins (Basel). 2020 Sep 11;12(9):585. doi: 10.3390/toxins12090585.
[D-Leu]MC-LR and MC-LR, two microcystins differing in one amino acid, constitute a sanitary and environmental problem owing to their frequent and concomitant presence in water bodies of the Americas and their association with human intoxication during recreational exposure to cyanobacterial bloom. Present in reservoirs used for irrigation as well, they can generate problems in the development of crops such as , of nutritional and economic interest to the region. Although numerous works address the toxic effects of MC-LR, information on the toxicity of [D-Leu]MC-LR is limited. Our objective was to study the toxic effects of [D-Leu]MC-LR and MC-LR (3.5 µg/ml) on after a single contact at the imbibition stage. Our findings indicate that 10 days post treatment, [D-Leu]MC-LR generates morphological and physiological alterations more pronounced than those caused by MC-LR. In addition to the alterations produced by [D-Leu]MC-LR in the development of seedlings and the structure of the leaves, roots and stems, we also found alterations in leaf stomatal density and conductivity, a longer delay in the phototropic response and a decrease in the maximum curvature angles achieved with respect to that observed for MC-LR. Our findings indicate that these alterations are linked to the greater inhibition of phosphatase activity generated by [D-Leu]MC-LR, rather than to oxidative damage. We observed that 30 days after treatment with MC-LR, plants presented better development and recovery than those treated with [D-Leu]MC-LR. Further studies are required on [D-Leu]MC-LR and MC-LR toxicity and their underlying mechanisms of action.
[D-亮氨酸]微囊藻毒素-LR（[D-Leu]MC-LR）和微囊藻毒素-LR（MC-LR）这两种仅一个氨基酸不同的微囊藻毒素，因其频繁且同时存在于美洲水体中，以及在娱乐活动接触蓝藻水华期间与人体中毒有关，构成了一个卫生和环境问题。它们也存在于用于灌溉的水库中，会给该地区具有营养和经济价值的作物（如 ）生长带来问题。尽管众多研究涉及MC-LR的毒性作用，但关于[D-Leu]MC-LR毒性的信息有限。我们的目标是研究[D-Leu]MC-LR和MC-LR（3.5微克/毫升）在吸胀阶段单次接触后对 的毒性作用。我们的研究结果表明，处理后10天，[D-Leu]MC-LR产生的形态和生理改变比MC-LR引起的更为明显。除了[D-Leu]MC-LR对幼苗发育以及叶片、根和茎结构产生的改变外，我们还发现叶片气孔密度和电导率发生了变化，向光反应延迟更长，相对于MC-LR观察到的最大曲率角减小。我们的研究结果表明，这些改变与[D-Leu]MC-LR对磷酸酶活性的更大抑制有关，而非氧化损伤。我们观察到，用MC-LR处理30天后的植物比用[D-Leu]MC-LR处理的植物生长和恢复得更好。需要对[D-Leu]MC-LR和MC-LR的毒性及其潜在作用机制进行进一步研究。
