Antagonistic and synergistic effects of light irradiation on the effects of copper on Chlamydomonas reinhardtii

Cheloni, Giulia; Cosio, Claudia

doi:10.1016/j.aquatox.2014.07.010

Cited by 37 publications

(47 citation statements)

References 43 publications

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“…A positive correlation between light radiation intensity and metal intracellular content was found for Cu in the green alga C. reinhardtii. In this study intracellular copper content was higher in cells exposed to solar simulated light as compared with cells incubated under low artificial light [75]. Significant increase of intracellular Cu was also found in the cyanobacterium Anabaena doliolum after short-term exposure to UVB radiation.…”

Section: Toxicokinetics Aspectsmentioning

confidence: 55%

“…However, in the natural environment, photosynthetic organisms are simultaneously exposed to visible and UVR light components, therefore the environmentally relevant knowledge about the interplay of solar light and trace metals is missing. The only study addressing the combined effects of Cu and simulated natural solar light on C. reinhardtii showed synergistic effects under solar simulated light with enhanced UVB radiation and antagonistic effects under solar simulated light with natural UVR intensity [75]. Overall, both increase and decrease of the trace metal adverse effects to photosynthetic microorganisms were reported for their combined exposure with light radiation (visible or UVR), depending on the microorganism and light intensity and spectral composition.…”

Section: Toxicodynamics Aspectsmentioning

confidence: 98%

“…A direct correlation was observed between light-associated variations of intracellular Cu, Cd and Zn concentration and growth, photosynthetic activity and oxidative stress [72,75,76]. Even less is known about sub-cellular metal distribution and other detoxification strategies, therefore further studies are highly sought to better elucidate the possible role of light irradiation on trace metal toxicokinetics.…”

Section: Toxicokinetics Aspectsmentioning

confidence: 99%

“…The research focused on different metals including Zn [72][73][74]103], Cd [7,64,72,98,100,102], Hg [100], Cu [62,75,76,97], Ni [64], Pb [64] and on different light radiation components: visible [72][73][74][75]99,102] and UV radiation [7,75,76,97,98,100,101]. Most of the work explored these combined effects on model organisms, mainly cyanobacterial species [72][73][74]99], but the results are rather contrasting.…”

Section: Toxicodynamics Aspectsmentioning

confidence: 99%

“…A significant number of studies explored the combined effects of metals and light on different eukaryotic algae and cyanobacteria [7,[72][73][74][75][76][97][98][99][100][101], as well as periphytic communities [102,103] ( Table 1). The research focused on different metals including Zn [72][73][74]103], Cd [7,64,72,98,100,102], Hg [100], Cu [62,75,76,97], Ni [64], Pb [64] and on different light radiation components: visible [72][73][74][75]99,102] and UV radiation [7,75,76,97,98,100,101].…”

Section: Toxicodynamics Aspectsmentioning

confidence: 99%

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Combined Effects of Trace Metals and Light on Photosynthetic Microorganisms in Aquatic Environment

Cheloni

2018

Environments

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Abstract:In the present review, we critically examine the state-of-the-art of the research on combined effects of trace metals and light on photosynthetic microorganisms in aquatic environment. Light of different intensity and spectral composition affects the interactions between trace metals and photosynthetic microorganisms directly, by affecting vital cellular functions and metal toxicokinetics and toxicodynamics, and indirectly, by changing ambient medium characteristics. Light radiation and in particular, the ultraviolet radiation component (UVR) alters the structure and reactivity of dissolved organic matter in natural water, which in most of the cases decreases its metal binding capacity and enhances metal bioavailability. The increase of cellular metal concentrations is generally associated with increasing light intensity, however further studies are necessary to better understand the underlying mechanisms. Studies on the combined exposures of photosynthetic microorganisms to metals and UVR reveal antagonistic, additive or synergistic interactions depending on light intensity, spectral composition or light pre-exposure history. Among the light spectrum components, most of the research was performed with UVR, while the knowledge on the role of high-intensity visible light and environmentally relevant solar light radiation is still limited. The extent of combined effects also depends on the exposure sequence and duration, as well as the species-specific sensitivity of the tested microorganisms and the activation of stress defense responses.

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Section: Toxicokinetics Aspectsmentioning

confidence: 55%

Section: Toxicodynamics Aspectsmentioning

confidence: 98%

Section: Toxicokinetics Aspectsmentioning

confidence: 99%

Section: Toxicodynamics Aspectsmentioning

confidence: 99%

Section: Toxicodynamics Aspectsmentioning

confidence: 99%

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Combined Effects of Trace Metals and Light on Photosynthetic Microorganisms in Aquatic Environment

Cheloni

2018

Environments

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Successful reversal of transgene silencing in Chlamydomonas reinhardtii

Beauchemin,

Merindol,

Fantino

et al. 2023

Biotechnology Journal

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Chlamydomonas reinhardtii has been successfully engineered to produce compounds of interest following transgene integration and heterologous protein expression. The advantages of this model include the availability of validated tools for bioengineering, its photosynthetic ability, and its potential use as biofuel. Despite this, breakthroughs have been hindered by its ability to silence transgene expression through epigenetic changes. Histone deacetylases (HDAC) are main players in gene expression. We hypothesized that transgene silencing can be reverted with chemical treatments using HDAC inhibitors. To analyze this, we transformed C. reinhardtii, integrating into its genome the mVenus reporter gene under the HSP70‐rbcs2 promoter. From 384 transformed clones, 88 (22.9%) displayed mVenus positive (mVenus+) cells upon flow‐cytometry analysis. Five clones with different fluorescence intensities were selected. The number of integrated copies was measured by qPCR. Transgene expression levels were followed over the growth cycle and upon SAHA treatment, using a microplate reader, flow cytometry, RT‐qPCR, and western blot analysis. First, we observed that expression varies with the cell cycle, reaching a maximum level just before the stationary phase in all clones. Second, we uncovered that supplementation with HDAC inhibitors of the hydroxamate family, such as vorinostat (suberoylanilide‐hydroxamic‐acid, SAHA) at the initiation of culture increases the frequency (% of mVenus+ cells) and the level of transgene expression per cell over the whole growth cycle, through histone deacetylase inhibition. Thus, we propose a new tool to successfully trigger the expression of heterologous proteins in the green algae C. reinhardtii, overcoming its main obstacle as an expression platform.This article is protected by copyright. All rights reserved

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Linking the chemical speciation of cerium to its bioavailability in water for a freshwater alga

El-Akl

Smith²,

Wilkinson

2015

Enviro Toxic and Chemistry

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Over the past decade, researchers have begun to use metals of the lanthanide family for numerous applications, including liquid crystal display (LCD) screens, optical fibers, and laser technology. Unfortunately, little is presently known about their bioavailability or the mechanisms by which they might cause toxicity. The present study focuses on cerium (Ce), one of the most widely used lanthanides, and on validating the biotic ligand model as a means to predict Ce bioaccumulation. Short-term exposures to Ce were performed using the unicellular alga Chlamydomonas reinhardtii, to better relate Ce bioavailability to its chemical speciation in solution. Maximum uptake fluxes (Jmax ) and affinity constants for the binding of Ce to the biological uptake sites (KS ) were established at pH 5.0 and pH 7.0. An apparent affinity constant of 1.8 × 10(7) M(-1) was observed at pH 5.0, with a larger value obtained at pH 7.0 (6 × 10(7) M(-1) ), albeit under conditions where equilibrium could not be confirmed. By evaluating Ce speciation using centrifugal ultrafiltration and single-particle inductively coupled plasma spectrometry, it could be concluded that very little (∼30%) Ce was truly dissolved at pH 7.0, with the majority of the metal being present in colloidal species. Speciation was also monitored by fluorescence to evaluate Ce complexation by natural organic matter (NOM). The presence of NOM decreased Ce bioaccumulation in line with free Ce concentrations. Finally, competition with calcium for the metal uptake sites was shown to result in a decrease in Ce uptake by C. reinhardtii.

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Antagonistic and synergistic effects of light irradiation on the effects of copper on Chlamydomonas reinhardtii

Cited by 37 publications

References 43 publications

Combined Effects of Trace Metals and Light on Photosynthetic Microorganisms in Aquatic Environment

Combined Effects of Trace Metals and Light on Photosynthetic Microorganisms in Aquatic Environment

Successful reversal of transgene silencing in Chlamydomonas reinhardtii

Linking the chemical speciation of cerium to its bioavailability in water for a freshwater alga

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