Differential effect of ultraviolet exposure (UVR) in the stress response of the Dinophycea Gymnodinium sp. and the Chlorophyta Dunaliella tertiolecta: mortality versus survival

Bouchard, Josée Nina; García‐Gómez, Candela; Lorenzo, M. Rosario; Segovia, Marı́a

doi:10.1007/s00227-013-2247-z

Cited by 17 publications

(26 citation statements)

References 59 publications

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“…Results of this investigation suggest that the algicide inhibits cell cycle progression for all three species tested and induces an autocatalytic, or PCD-like response similar to those as observed in other phytoplankton under stress [refs 5, 7, 9, 10 and 29 among many others]. PCD has been extensively characterized in metazoans30 and is an essential process for proper development, function and survival.…”

Section: Discussionmentioning

confidence: 56%

Cell cycle arrest and biochemical changes accompanying cell death in harmful dinoflagellates following exposure to bacterial algicide IRI-160AA

Pokrzywinski

Tilney

Warner

et al. 2017

Sci Rep

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Bacteria may play a role in regulating harmful algal blooms, but little is known about the biochemical and physiological changes associated with cell death induced by algicidal bacteria. Previous work characterized an algicidal exudate (IRI-160AA) produced by Shewanella sp. IRI-160 that is effective against dinoflagellates, while having little to no effect on other phytoplankton species in laboratory culture experiments. The objective of this study was to evaluate biochemical changes associated with cell death and impacts on the cell cycle in three dinoflagellate species (Prorocentrum minimum, Karlodinium veneficum and Gyrodinium instriatum) after exposure to IRI-160AA. In this study, IRI-160AA induced cell cycle arrest in all dinoflagellates examined. Several indicators for programmed cell death (PCD) that are often observed in phytoplankton in response to a variety of stressors were also evaluated. Cell death was accompanied by significant increases in DNA degradation, intra- and extracellular ROS concentrations and DEVDase (caspase-3 like) protease activity, which have been associated with PCD in other phytoplankton species. Overall, results of this investigation provide strong evidence that treatment with the bacterial algicide, IRI-160AA results in cell cycle arrest and induces biochemical changes consistent with stress-related cell death responses observed in other phytoplankton.

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Section: Discussionmentioning

confidence: 56%

Cell cycle arrest and biochemical changes accompanying cell death in harmful dinoflagellates following exposure to bacterial algicide IRI-160AA

Pokrzywinski

Tilney

Warner

et al. 2017

Sci Rep

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“…the same spectral irradiance conditions with increased UVR to PAR ratios, and therefore the same UVR biological effective doses), D. tertiolecta cells survived chronic UVR exposure by activation of DNA repair mechanisms by means of cellular proliferation nuclear antigen (PCNA) and repressor of silencing 1 (ROS1) protein accumulation, and that activation of mitogen activated protein kinase (MAPK)‐like proteins mediated the process. By comparing predictive models (models demonstrating that when repair is absent or slow, responses depend on cumulative exposure, and when repair is present, responses are spectral‐dependent with experimental data, the authors also confirmed that repair was indeed a key element in D. tertiolecta resilience , in which the activation of antioxidant enzymes had a priority role to detoxify and protect the cells by scavenging ROS. The net effect of UVR exposure on phytoplankton survival reflects a balance between damage, repair processes and the energetic cost of photoprotection .…”

Section: Introductionmentioning

confidence: 78%

“…Despite the considerable contribution of marine phytoplankton to global climate and biogeochemical cycles, the mechanisms driving the UV inhibition of primary production are complex, and are the aim of this study. For example short wavelengths of the solar spectrum injure phytoplankton by inducing photobleaching of photosynthetic pigments by damaging DNA , and by alteration of complexes and molecules present in the photosynthetic apparatus such as the photosystem II complex (PSII) and/or the rubisco enzyme . The consequence is that essential physiological processes of phytoplankton are affected .…”

Section: Introductionmentioning

confidence: 99%

Dunaliella tertiolecta (Chlorophyta) Avoids Cell Death Under Ultraviolet Radiation By Triggering Alternative Photoprotective Mechanisms

Segovia

Mata

Palma

et al. 2015

Photochem & Photobiology

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The effect of different ultraviolet radiation (UVR) treatments combining PAR (P), UVA (A) and UVB (B) on the molecular physiology of Dunaliella tertiolecta was studied during 6 days to assess the response to chronic UVR exposure. UVR reduced cell growth but did not cause cell death, as shown by the absence of SYTOX Green labeling and cellular morphology. However, caspase-like enzymatic activities (CLs), (regarded as cell death proteases), were active even though the cells were not dying. Maximal quantum yield of fluorescence (Fv /Fm ) and photosynthetic electron transport rate (ETR) dropped. Decreased nonphotochemical quenching (NPQ) paralleled a drop in xanthophyll cycle de-epoxidation under UVB. Reactive oxygen species (ROS) and D1 protein accumulation were inversely correlated. PAB exhibited elevated ROS production at earlier times. Once ROS decayed, D1 protein recovered two-fold compared with P and PA at later stages. Therefore, PsbA gene was still transcribed, suggesting ROS involvement in D1 recovery by its direct effect on mRNA-translation. We add evidence of an UVB-induced positive effect on the cells when P is present, providing photoprotection and resilience, by means of D1 repair. This allowed cells to survive. The photoprotective mechanisms described here (which are counterintuitive in principle) conform to an important ecophysiological response regarding light stress acclimation.

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“…described inBouchard et al (2013) 21. Briefly, ROS detection was performed using carboxy-H 2 DFFDA (Invitrogen, Oregon, USA).…”

mentioning

confidence: 99%

Elevated CO2 alleviates high PAR and UV stress in the unicellular chlorophyte Dunaliella tertiolecta

García‐Gómez

Gordillo

Palma

et al. 2014

Photochem Photobiol Sci

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The effects of increased CO₂ and irradiance on the physiological performance of the chlorophyte Dunaliella tertiolecta were studied at different PAR and UVR (UVA+UVB) irradiances, simulating the solar radiation at different depths, under present (390 ppmv, LC) and predicted CO₂ levels (1000 ppmv, HC). Cell stress after UVR-exposure was mostly attenuated under HC levels, as evidenced by a decrease in reactive oxygen species accumulation. DNA damage showed a 42-fold increase in cyclobutane-pyrimidine dimers formation under the highest irradiance in LC with respect to the lowest irradiance. Photolyase gene expression was upregulated under HC resulting in a drastic decrease in CPDs accumulation to only 25% with respect to LC. However, the expression of genes related to the replacement of photosynthetic apparatus proteins (PsbA and LHCII) were downregulated at HC compared to LC. Proliferating cell nuclear antigen (PCNA) accumulation was always higher in HC and the accumulation pattern indicated its involvement in DNA repair or growth depending on the irradiance doses. Our results suggest that marine unicellular chlorophytes might possibly become more resilient to UVR exposure under future CO₂ regimes.

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Differential effect of ultraviolet exposure (UVR) in the stress response of the Dinophycea Gymnodinium sp. and the Chlorophyta Dunaliella tertiolecta: mortality versus survival

Cited by 17 publications

References 59 publications

Cell cycle arrest and biochemical changes accompanying cell death in harmful dinoflagellates following exposure to bacterial algicide IRI-160AA

Cell cycle arrest and biochemical changes accompanying cell death in harmful dinoflagellates following exposure to bacterial algicide IRI-160AA

Dunaliella tertiolecta (Chlorophyta) Avoids Cell Death Under Ultraviolet Radiation By Triggering Alternative Photoprotective Mechanisms

Elevated CO2 alleviates high PAR and UV stress in the unicellular chlorophyte Dunaliella tertiolecta

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