Photochemical responses of three marine phytoplankton species exposed to ultraviolet radiation and increased temperature: Role of photoprotective mechanisms

Halac, Silvana R.; Villafañe, Virginia E.; Gonçalves, Rodrigo J.; Helbling, E. Walter

doi:10.1016/j.jphotobiol.2014.09.022

Cited by 22 publications

(17 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Small cells are also vulnerable to the accumulation of cyclobutane pyrimidine dimers but photosynthesis is less inhibited by UVB radiation, which may be caused by faster photo-repair in small cells (Buma et al, 2003). However, other factors such as bio-optical characteristics (Figueroa et al, 1997) and intraspecific differences (Halac et al, 2014) may outweigh the effects of cell size. As a consequence, there is currently no agreement on the generality of the relationship between cell size and UVB sensitivity across freshwater and marine microalgae.…”

Section: Introductionmentioning

confidence: 99%

Contrasting Responses of Marine and Freshwater Photosynthetic Organisms to UVB Radiation: A Meta-Analysis

2017

View full text Add to dashboard Cite

Ultraviolet-B (UVB) radiation is a global stressor that has profound impacts on freshwater and marine ecosystems. However, an analysis of the patterns of sensitivity to UVB radiation across aquatic photosynthetic organisms has not yet been published. Here, we performed a meta-analysis on results reported in 214 studies compiled from the published literature to quantify and compare the magnitude of responses of aquatic photosynthetic organisms to changes in UVB radiation. The meta-analysis was conducted on observations of marine (n = 893) and freshwater macroalgae (n = 126) and of marine (n = 1,087) and freshwater (n = 2,889) microalgae (total n = 4,995). Most of these studies (85%) analyzed the performance of organisms exposed to natural solar radiation when UVB was partially or totally reduced compared with the organismal performance under the full solar radiation spectrum, whereas the remaining 15% of the studies examined the responses of organisms to elevated UVB radiation mostly using artificial lamps. We found that marine photosynthetic organisms tend to be more sensitive than freshwater photosynthetic organisms to UVB radiation; responses to either decreased or increased UVB radiation vary among taxa; the mortality rate is the most sensitive of the trait responses to elevated UVB radiation, followed by changes in cellular and molecular traits; the sensitivity of microalgae to UVB radiation is dependent on size, with small-celled microalgae more sensitive than large-celled microalgae to UVB radiation. Thick macroalgae morphotypes were the less sensitive to UVB, but this effect could not be separated from phylogenetic differences. The high sensitivity of marine species, particularly the smallest photosynthetic organisms, to increased UVB radiation suggests that the oligotrophic ocean, a habitat comprising 70% of the world's oceans with high UVB penetration and dominated by picoautotrophs, is extremely vulnerable to changes in UVB radiation.

show abstract

Section: Introductionmentioning

confidence: 99%

Contrasting Responses of Marine and Freshwater Photosynthetic Organisms to UVB Radiation: A Meta-Analysis

2017

View full text Add to dashboard Cite

show abstract

“…For the applied temperature range in the present study, the growth rate of the benthic species showed a slight response, while growth increased with temperature to a greater extent in the planktonic species, particularly above 25 • C. However, life forms in the natural environment are affected by multiple stressors concomitantly (Boyd et al, 2015). For instance, recent studies have demonstrated that increased temperature would affect phytoplankton interactively with light intensity (Edwards et al, 2016) and could alleviate UV direct inhibition in some sensitive species (Halac et al, 2014). Moreover, in diatoms short-term changes in temperature showed a greater interaction with UV radiation than did long-term exposure, which was particularly important for intertidal benthic species (Sobrino and Neale, 2007).…”

Section: Discussionmentioning

confidence: 52%

“…As predicted, the benthic species had a higher tolerance to the combination of extreme temperature and UV radiation, which can be attributed to the environment in which were living. Below the optimal temperature, both species performed better in response to UV radiation under elevated temperature, suggesting that the natural variation of temperature due to changes in the heat flux from the sun or meteorological events would alter the extent of UV effects on primary producers, and therefore the aquatic ecosystem (Häder et al, 2011). Furthermore, considering the projected global warming scenarios, UV radiation could impose different impacts on phytoplankton with respect to the regional differences (Beardall et al, 2009;Xie et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

“…Considering the importance of diatoms to coastal primary productivity (Carstensen et al, 2015), their responses to environmental factors are of considerable interest (Häder et al, 2011). However, the niches in which planktonic and benthic diatom species exist have quite different physical and chemical characteristics (Souffreau et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Differential photosynthetic responses of marine planktonic and benthic diatoms to ultraviolet radiation under various temperature regimes

Yue

et al. 2017

Biogeosciences

View full text Add to dashboard Cite

Abstract. We studied the photophysiological responses to ultraviolet radiation (UVR) of two diatoms, isolated from different environmental niches. Both species showed the highest sensitivity to UV radiation under relatively low temperature, while they were less inhibited under moderately increased temperature. Under the highest temperature applied in this study, the benthic diatom Nitzschia sp. showed minimal sensitivity to UV radiation, while inhibition of the planktonic species, Skeletonema sp., increased further compared with that at the growth temperature. These photochemical responses were linked to values for the repair and damage processes within the cell; higher damage rates and lower repair rates were observed for Skeletonema sp. under suboptimal temperature, while for Nitzschia sp., repair rates increased and damage rates were stable within the applied temperature range. Our results suggested that the response of the microalgae to UV radiation correlated with their niche environments, the periodic exposure to extreme temperatures promoting the resistance of the benthic species to the combination of high temperature and UV radiation.

show abstract

“…UVR in the marine environment is shaping the distribution of organisms along a vertical gradient (Halac et al 2014) and in turn drives the evolution of tolerance mechanisms in anthozoans (Siebeck 1988). DNA damage (Buma et al 2001) and even cell death (Agustí et al 2010) can be detected along a depth-and therefore dose gradient in Antarctic phytoplankton and Mediterranean cyanobacteria.…”

Section: Figure 12mentioning

confidence: 99%

UV-induced DNA damage in coral reef fish: damage levels and protection mechanisms

Braun¹

View full text Add to dashboard Cite

Ultraviolet radiation (UVR) reaching the surface of earth has been recognized as a major environmental stressor for marine organisms due to the potential of UVB (280 -315 nm) to induce DNA damage such as cyclobutane pyrimidine dimers (CPDs) that can lead to cell death. Despite inhabiting a UV-rich environment, the levels of DNA damage in reef fish and factors influencing these levels are unknown. Whether reef fish are able to avoid UVR and repair UV-induced DNA damage is unclear despite the importance of these protection mechanisms in other animals. The presence of UV-absorbing Mycosporine-like Amino Acids (MAAs) in the external mucus of reef fish has been confirmed, however the efficiency of these compounds in preventing CPDs has not been studied. The aim of this PhD was to assess the impact of ambient and elevated levels of UVR on reef fish in terms of UV-induced DNA damage, and to evaluate the protective mechanisms available to fish with and without UV vision.In order to determine the net level of DNA damage in skin samples of 15 species of fish from the reefs surrounding Lizard Island, a CPD-specific antibody was used in an ELISA. Analysis using a boosted regression tree shows that the most important factors governing CPDs were species and size, with higher damage being detected in smaller individuals. Other factors such as family, depth and the presence or absence of UV vision contributed the least to the variation in damage. The length of exposure to natural levels of UVR over the course of a day was found to have no significant influence on net DNA damage levels, which were relatively low in situ, compared to levels that were detected in later experiments using elevated UVR.The first protection mechanism, behavioural avoidance to UVR, was tested using behavioural experiments in which fish with (Pomacentrus amboinensis) and without UV vision (Thalassoma lunare) were given a choice between UV-protected and UV-exposed compartments. Additionally, foraging behaviour of settlement-stage larvae of P. amboinensis was determined under ambient levels of UVR. Automated analysis of video footage using MatLab shows that neither species showed a specific avoidance response to varying levels of UVB. Although P. amboinensis showed a preference for deeper sections of the experimental tanks, fish spent equal amounts of time in exposed and protected compartments. The foraging activity and distance to shelter of P. amboinensis that were exposed to UVR were significantly reduced compared to fish that were observed under light conditions that lacked UVR.Next, the efficiency of natural sunscreens, MAAs, in preventing CPDs was tested in P. amboinensis and T. lunare. The levels of MAAs in the mucus of the two species were either reduced or maintained during captivity before exposure to a short pulse of high UVR.Spectrometric measurements of light transmission through mucus samples collected after irradiation were used to quantify the amount of MAAs available for protection. In both species, DNA damage levels in skin sampl...

show abstract

Photochemical responses of three marine phytoplankton species exposed to ultraviolet radiation and increased temperature: Role of photoprotective mechanisms

Cited by 22 publications

References 39 publications

Contrasting Responses of Marine and Freshwater Photosynthetic Organisms to UVB Radiation: A Meta-Analysis

Contrasting Responses of Marine and Freshwater Photosynthetic Organisms to UVB Radiation: A Meta-Analysis

Differential photosynthetic responses of marine planktonic and benthic diatoms to ultraviolet radiation under various temperature regimes

UV-induced DNA damage in coral reef fish: damage levels and protection mechanisms

Contact Info

Product

Resources

About