Multiple-endpoint assay provides a detailed mechanistic view of responses to herbicide exposure in Chlamydomonas reinhardtii

Nestler, Holger; Groh, Ksenia J.; Schönenberger, René; Behra, Renata; Schirmer, Kristin; Eggen, Rik I.L.; Suter, Marc J.‐F.

doi:10.1016/j.aquatox.2012.01.014

Cited by 72 publications

(63 citation statements)

References 41 publications

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“…This is in agreement with previous findings of only a slight effect on cell growth when C. reinhardtii was exposed to Nf 10 µM, a concentration 4 times higher than the highest concentration used in our study (2.5 µM) (Nestler et al, 2012). Considering the strong decrease in photosynthetic efficiency with this herbicide, we suggest that, over the course of 4 d, C. reinhardtii was using its energy reserves to maintain a similar growth rate in cultures exposed to Nf or Fd, compared with the controls.…”

Section: Discussionsupporting

confidence: 83%

Combined effect of temperature and bleaching herbicides on photosynthesis, pigment and fatty acid composition ofChlamydomonas reinhardtii

Chalifour

Arts

Kainz

et al. 2014

European Journal of Phycology

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Norflurazon (Nf) and fluridone (Fd) are phytoene desaturase inhibitor herbicides that are widely used for the control of grasses and invasive aquatic weeds, respectively. These herbicides enter aquatic environments where they can negatively affect non-target plant species (e.g. algae). Their toxicity towards algae may be modified by abiotic factors such as light intensity, temperature, pH and nutrients. Investigating the effect of low temperature on the toxicity of Nf and Fd is particularly important because both temperature and herbicides affect some of the same physiological process (e.g. carotenoid biosynthesis). Here we demonstrate that Nf reduced photosynthesis in the green alga Chlamydomonas reinhardtii more strongly at 15 than at 25ºC, while Fd showed stronger effects at 25 than at 15ºC. Neither herbicide significantly inhibited photosynthesis at 8ºC. Although the overall pigment content decreased with lower temperature, there was an increase in photo-protective carotenoids relative to chlorophylls at both 15 and 8ºC in the absence of herbicides. Moreover, most of the measured pigments decreased markedly in the presence of Nf and Fd at 15 and 25ºC, including β-carotene which fell to below detection limits. The fatty acid composition was modified by temperature and the level of unsaturation noticeably increased at 15 compared with 25ºC. At 8ºC, however, despite a 2.4 times decrease in fatty acid content, the unsaturation level was similar to 25ºC acclimated cells. Monounsaturated fatty acids increased concomitant with a decrease in polyunsaturated fatty acid in the 2.5 µM Nf treatment at 25ºC. Differences in the effect of Nf and Fd on photosynthesis at 15 and 25ºC can be attributed to the marked decrease in carotenoids, which play an important role in photoprotection. At 8ºC, the apparent lack of inhibitory effects compared with control cultures could be due to enhanced photoprotection and/or decreased uptake of herbicides by the alga.

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Section: Discussionsupporting

confidence: 83%

Combined effect of temperature and bleaching herbicides on photosynthesis, pigment and fatty acid composition ofChlamydomonas reinhardtii

Chalifour

Arts

Kainz

et al. 2014

European Journal of Phycology

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“…Energy. Energy content of the cells in the form of ATP is a sensitive endpoint in C. reinhardtii for determining the toxicity of chemicals (37). The ATP content responded to Ag + exposure and decreased significantly in C. reinhardtii at concentrations greater than 100 nM (Fig.…”

Section: Resultsmentioning

confidence: 99%

Linking toxicity and adaptive responses across the transcriptome, proteome, and phenotype of Chlamydomonas reinhardtii exposed to silver

Pillai

Behra

Nestler

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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145

102

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Significance Comprehending the responses of organisms to pollutants by a systems-based approach allows characterization of molecular events and the cellular pathways that have been perturbed. However, mapping only adverse outcomes of a toxicant in an organism falls short of describing the defense response that is mounted to maintain homeostasis and resistance to the toxic insult. Our study provides the understanding of molecular mechanisms of algae in response to silver, which in turn indicates how the algae might behave in a silver contamination scenario. We have used complementary information obtained from the transcriptome, proteome, and physiology to gain mechanistic insights into the responses of Chlamydomonas reinhardtii . We show here the importance of stress and adaptive responses, especially at sublethal concentrations of pollutant.

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“…The value of AEC can reflect energy metabolism under toxic stress (Padinha et al 2000;Nestler et al 2012). Here, the values of AEC increased from 0.68 to 0.72, and the maximum value (0.72) occurred when 5 ng/L of CTAB was applied (Table 1).…”

Section: Low Concentrations Of Ctab Increased Photosynthetic Activitymentioning

confidence: 96%

“…For instance, the concentration of Cd 2+ (less than 0.1 mg/L) increased the removal efficiency of both ammonia nitrogen (NH 4 + ) and total phosphorus (TP) by increasing the release of the extracellular polymeric substances (EPS) in Chlorella vulgaris, which reduced the toxicity of Cd 2+ through the interaction of Cd 2+ with polysaccharides and protein in EPS fraction. Hormesis is a phenomenon that describes a dose-response relationship characterized by a low-dose stimulation and a high-dose inhibition by various chemical stressors; the maximum degree of hormesis is generally observed to be within 30-60 % organismal response compared to the corresponding control (Calabrese 2001(Calabrese , 2013Nestler et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Nutrient removal by Chlorella vulgaris F1068 under cetyltrimethyl ammonium bromide induced hormesis

Zhou

et al. 2016

Environ Sci Pollut Res

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Toxicants are generally harmful to biotechnology in wastewater treatment. However, trace toxicant can induce microbial hormesis, but to date, it is still unknown how this phenomenon affects nutrient removal during municipal wastewater treatment process. Therefore, this study focused on the effects of hormesis induced by cetyltrimethyl ammonium bromide (CTAB), a representative quaternary ammonium cationic surfactant, on nutrient removal by Chlorella vulgaris F1068. Results showed that when the concentration of CTAB was less than 10 ng/L, the cellular components chlorophyll a, proteins, polysaccharides, and total lipids increased by 10.11, 58.17, 38.78, and 11.87 %, respectively, and some enzymes in nutrient metabolism of algal cells, such as glutamine synthetase (GS), acid phosphatase (ACP), H(+)-ATPase, and esterase, were also enhanced. As a result, the removal efficiencies of ammonia nitrogen (NH4 (+)) and total phosphorus (TP) increased by 14.66 and 8.51 %, respectively, compared to the control during a 7-day test period. The underlying mechanism was mainly due to an enhanced photosynthetic activity of C. vulgaris F1068 indicated by the increase in chlorophyll fluorescence parameters (the value of Fv/Fm, ΦII, Fv/Fo, and rETR increased by 12.99, 7.56, 25.59, and 8.11 %, respectively) and adenylate energy charge (AEC) (from 0.68 to 0.72). These results suggest that hormesis induced by trace toxicants could enhance the nutrient removal, which would be further considered in the design of municipal wastewater treatment processes. Graphical abstract The schematic mechanism of C. vulgaris F1068 under CTAB induced hormesis. Green arrows ( ) represent the increase and the red arrow ( ) represents the decrease.

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Multiple-endpoint assay provides a detailed mechanistic view of responses to herbicide exposure in Chlamydomonas reinhardtii

Cited by 72 publications

References 41 publications

Combined effect of temperature and bleaching herbicides on photosynthesis, pigment and fatty acid composition ofChlamydomonas reinhardtii

Combined effect of temperature and bleaching herbicides on photosynthesis, pigment and fatty acid composition ofChlamydomonas reinhardtii

Linking toxicity and adaptive responses across the transcriptome, proteome, and phenotype of Chlamydomonas reinhardtii exposed to silver

Nutrient removal by Chlorella vulgaris F1068 under cetyltrimethyl ammonium bromide induced hormesis

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