Microcystins induce morphological and physiological changes in selected representative phytoplanktons
Microcystins induce morphological and physiological changes in selected representative phytoplanktons
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DOI：
10.1007/s00248-004-0189-1
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发表时间：
2005-08-01
影响因子：
3.6
通讯作者：
Elersek, T
中科院分区：
文献类型：
--
作者：
Sedmak, B;Elersek, T
溶解的微囊藻毒素 (MC) 经常存在于水中，其中以产生微囊藻毒素、形成水华的蓝藻为主。三种最常见的微囊藻毒素MC-LR、-RR和-YR的环境可行浓度（5 x 10(-7) M）的体外实验表明，它们会影响不同代表性浮游植物的代谢。在接近蓝藻水华环境的光强度（50 μ mol m(-2) s(-1)）下，它们会在产生微囊藻毒素和不产生微囊藻毒素的铜绿微囊藻菌株中产生形态和生理变化，并且对蓝藻水华中经常存在的绿藻四尾栅藻也有类似的影响。测试的所有三种微囊藻毒素变体都会诱导细胞聚集、细胞体积增加以及光合色素的过量产生。这三种效应似乎彼此相关，但不一定是由相同的机制引起的。微囊藻毒素对光生物体的光捕获复合物的生物活性可以解释为一个信号，宣告由于蓝细菌的大量增殖而导致光条件恶化。尽管微囊藻毒素的功能仍不清楚，但很明显它们对自然界的浮游植物生物体具有多种影响。这些影响取决于个体生物体以及各种细胞内和细胞外信号传导途径。溶解的微囊藻毒素也会影响产生微囊藻毒素的蓝藻的生理学，这一事实使我们得出这样的结论：微囊藻毒素在产生细胞中的作用不同于它们在水环境中的作用。
Dissolved microcystins (MC) are regularly present in water dominated by microcystin-producing, bloom-forming cyanobacteria. In vitro experiments with environmentally feasible concentrations (5 x 10(-7) M) of the three most common microcystins, MC-LR, -RR, and -YR, revealed that they influence the metabolism of different representative phytoplanktons. At light intensities close to the cyanobacterial bloom environment (50 mu mol m(-2) s(-1)), they produce morphological and physiological changes in both microcystin-producing and nonproducing Microcystis aeruginosa strains, and also have similar effects on the green alga Scenedesmus quadricauda that is frequently present in cyanobacterial blooms. All three microcystin variants tested induce cell aggregation, increase in cell volume, and overproduction of photosynthetic pigments. All three effects appear to be related to each other, but are not necessarily caused by the same mechanism. The biological activity of microcystins toward the light-harvesting complex of photobionts can be interpreted as a signal announcing the worsening of light conditions due to the massive proliferation of cyanobacteria. Although the function of microcystins is still unknown, it is evident that they have numerous effects on phytoplankton organisms in nature. These effects depend on the individual organism as well as on the various intracellular and extracellular signaling pathways. The fact that dissolved microcystins also influence the physiology of microcystin-producing cyanobacteria leads us to the conclusion that the role of microcystins in the producing cells differs from their role in the water environment.