Attack of Microcystis aeruginosa bloom on a Ceratophyllum submersum field: Ecotoxicological measurements in real environment with real microcystin exposure
| Autor: | Milán Riba, Márta M-Hamvas, Gábor Vasas, Gyöngyi Gyémánt, György Vereb, Tamás Garda, Andrea Zsuzsanna Ujvárosi, Csaba Máthé |
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| Rok vydání: | 2019 |
| Předmět: |
Cyanobacteria
Microcystis Environmental Engineering Microcystins 010504 meteorology & atmospheric sciences Harmful Algal Bloom Biológiai tudományok Microcystin 010501 environmental sciences 01 natural sciences Algal bloom Magnoliopsida chemistry.chemical_compound Természettudományok Aquatic plant Environmental Chemistry Microcystis aeruginosa Waste Management and Disposal 0105 earth and related environmental sciences chemistry.chemical_classification Hungary biology fungi food and beverages Biotic stress biology.organism_classification Pollution Lakes chemistry Biochemistry Chlorophyll Shoot |
| Zdroj: | Science of The Total Environment. 662:735-745 |
| ISSN: | 0048-9697 |
| Popis: | Overproduction of toxic cyanobacteria is a type of harmful algal blooms (HABs). The heptapeptide microcystins (MCs) are one of the most common cyanotoxins. There is increasing research concerning the effects of MCs on growth and physiology of vascular plants, however there is a lack of studies on their direct effects on aquatic macrophytes in the real environment. Here we report the occurrence of a MC producing HAB in Lake Bardos, Hungary in 2012 with harmful effects on cytological, histological and biochemical parameters of Ceratophyllum submersum (soft hornwort) plants naturally growing at the blooming site. Blue-Green Sinapis Test (BGST) showed high toxicity of HAB samples. Cell-free water samples contained a significant amount of MCs (7.31 ± 0.17 μg L−1) while C. submersum plants contained 1.01 ± 0.21 μg g DW−1 MCs. Plants showed significant increases of protein content and decreases of anthocyanin content and carotenoid/chlorophyll ratio, indicating physiological stress- as compared to plants from the control (MC free) sampling site of the same water body. Histological and cytological studies showed (i) radial swelling and the abnormal formation of lateral buds at the shoot tip leading to abnormal development; (ii) the fragmentation of nuclei as well as accumulation of phenolics in the nucleus indicating that the HAB induced cell death and stress reactions at the nuclear level. The most relevant effect was the increase of histone H3 phosphorylation in metaphase chromosomes: since MCs are strong inhibitors of protein phosphatases, this alteration is related to the biochemical targets of these toxins. The HAB decreased peroxidase activity, but increased nuclease and protease activities, showing the decreased capacity of plants to face biotic stress and as the cytological changes, the induction of cell death. This study is one of the first to show the complex harmful changes in aquatic plants that co-exist with HABs. |
| Databáze: | OpenAIRE |
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