Activation of stress reactions in the dinophyte microalga Prorocentrum cordatum as a consequence of the toxic effect of ZnO nanoparticles and zinc sulfate.

Autor: Shoman N; A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, 2, Nakhimov Ave., Sevastopol, Russia. Electronic address: n-zaichencko@yandex.ru., Solomonova E; A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, 2, Nakhimov Ave., Sevastopol, Russia., Akimov A; A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, 2, Nakhimov Ave., Sevastopol, Russia., Rylkova O; A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, 2, Nakhimov Ave., Sevastopol, Russia., Mansurova I; A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, 2, Nakhimov Ave., Sevastopol, Russia.
Jazyk: angličtina
Zdroj: Aquatic toxicology (Amsterdam, Netherlands) [Aquat Toxicol] 2024 Jul; Vol. 272, pp. 106964. Date of Electronic Publication: 2024 May 20.
DOI: 10.1016/j.aquatox.2024.106964
Abstrakt: According to the results of the experimental study, the main regularities of changes in morphological, structural-functional and fluorescent indices of P. cordatum were established when zinc oxide nanoparticles ZnO NPs (0.3-6.4 mg L -1 ) and Zn in form of salt (0.09-0.4 mg L -1 ) were added to the medium. The studied pollutants have cytotoxic (growth inhibition, development of oxidative stress, destruction of cytoplasmic organelles, disorganization of mitochondria) and genotoxic (changes in the morphology of nuclei, chromatin condensation) effects on microalgae, affecting almost all aspects of cell functioning. Despite the similar mechanism of action of zinc sulfate and ZnO NPs on P. cordatum cells, the negative effect of ZnO NPs is also due to the inhibition of photosynthetic activity of cells (significant decrease in the maximum quantum yield of photosynthesis and electron transport rate), reduction of chlorophyll concentration from 3.5 to 1.8 pg cell -1 , as well as mechanical effect on cells: deformation and damage of cell membranes, aggregation of NPs on the cell surface. Apoptosis-like signs of cell death upon exposure to zinc sulfate and ZnO NPs were identified by flow cytometry and laser scanning confocal microscopy methods: changes in cell morphology, cytoplasm retraction, development of oxidative stress, deformation of nuclei, and disorganization of mitochondria. It was shown that the first signs of cell apoptosis appear at 0.02 mg L -1 Zn and 0.6 mg L -1 ZnO NPs after 72 h of exposure. At higher concentrations of pollutants, a dose-dependent decrease in algal enzymatic activity (up to 5 times relative to control) and mitochondrial membrane potential (up to 4 times relative to control), and an increase in the production of reactive oxygen species (up to 4-5 times relative to control) were observed. The results of the presented study contribute to the disclosure of fundamental mechanisms of toxic effects of pollutants and prediction of ways of phototrophic microorganisms reaction to this impact.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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