Diel and depth profiles of DNA photodamage in bacterioplankton exposed to ambient solar ultraviolet radiation

Jeffrey, Wade H.; Pledger, Ralph J.; Aas, Peter; Hager, Silvia; Coffin, Richard B.; Haven, Robin Von; Mitchell, David L.

doi:10.3354/meps137283

Cited by 178 publications

(195 citation statements)

References 19 publications

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“…For example, prokaryotes because of their simpler organization could metabolize more rapidly during the day, at the expense of having to wait for the return of the light period to resume growth. Eukaryotes may have evolved a more sophisticated strategy, restricting to the dark period all processes that do not strictly require light or that may be susceptible to photodamage such as DNA replication (oceanic eukaryotes may repair DNA damages more slowly than procaryotes [Jeffrey et al, 1996]). These dephasings between populations could also be due to the specificity of their respective endogenous clocks.…”

Section: Size and Fluorescence Diel Patternsmentioning

confidence: 99%

Diel variability of photosynthetic picoplankton in the equatorial Pacific

Vaulot¹,

Marie²

1999

J. Geophys. Res.

199

172

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Abstract. The diel variability in cell abundance, light scatter, and pigment fluorescence of three autotrophic picoplankton groups (Prochlorococcus, Synechococcus, picoeukaryotes) measured by flow cytometry was investigated in surface waters of the equatorial Pacific Ocean (5øS, 150øW) during 5 days with about 1 hour temporal resolution. The diel variability of vertical profiles was examined at the same station on days 2 and 4. Prochlorococcus division rate was also estimated from cell cycle measurements. A more limited data set was obtained at a station located in very oligotrophic waters (16øS, 150øW). All three picoplankton populations exhibited very marked diel variability. Cell division was highly synchronized but not phased identically for all three populations: Synechococcus divided first, followed 2 hours later by Prochlorococcus and 7 hours later by picoeukaryotes. Cells grew in size only once the sun had risen, but growth did continue in the dark for a short period. Growth processes occurred in parallel at the top and the bottom of the mixed layer, inducing uniform profiles for cell abundance and scatter. For chlorophyll fluorescence, in contrast, prokaryotes displayed opposite patterns during the light period between surface (decrease due to very strong quenching) and depth (increase). This created steep vertical gradients during the day that vanished at night because of convective mixing. In the top 25 m, strong light intensities (including UV radiation) had very pronounced detrimental effects on prokaryotes, especially on Prochlorococcus, inducing fluorescence quenching, slowed down growth, and retardation of DNA synthesis.

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Section: Size and Fluorescence Diel Patternsmentioning

confidence: 99%

Diel variability of photosynthetic picoplankton in the equatorial Pacific

Vaulot¹,

Marie²

1999

J. Geophys. Res.

199

172

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“…This is of interest to biologists, because UV is known to inhibit phytoplankton productivity [Cullen and Neale, 1994] and to damage bacteria [Jeffrey et al, 1996;Kaiser and Herndl, 1997;Jeffrey et al, 2000].…”

Section: Introductionmentioning

confidence: 99%

Calculation of UV attenuation and colored dissolved organic matter absorption spectra from measurements of ocean color

2003

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[1] The absorption of ultraviolet and visible radiation by colored or chromophoric dissolved organic matter (CDOM) drives much of marine photochemistry. It also affects the penetration of ultraviolet radiation (UV) into the water column and can confound remote estimates of chlorophyll concentration. Measurements of ocean color from satellites can be used to predict UV attenuation and CDOM absorption spectra from relationships between visible reflectance, UV attenuation, and absorption by CDOM. Samples were taken from the Bering Sea and from the Mid-Atlantic Bight, and water types ranged from turbid, inshore waters to the Gulf Stream. We determined the following relationships between in situ visible radiance reflectance, L u /E d (l) (sr À1 ), and diffuse attenuation of UV,. Consistent with published observations, these empirical relationships predict that the spectral slope coefficient of CDOM absorption increases as diffuse attenuation of UV decreases. Excluding samples from turbid bays, the ratio of the CDOM absorption coefficient to K d is 0.90 at 323 nm, 0.86 at 338 nm, and 0.97 at 380 nm. We applied these relationships to SeaWiFS images of normalized water-leaving radiance to calculate the CDOM absorption and UV attenuation in the Mid-Atlantic Bight in May, July, and August 1998. The images showed a decrease in UV attenuation from May to August of approximately 50%. We also produced images of the areal distribution of the spectral slope coefficient of CDOM absorption in the Georgia Bight. The spectral slope coefficient increased offshore and changed with season.

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“…of potential hosts, as well as transformations inflicted on the organic substances that serve as substrates for some of these microorganisms (Visser et al, 1999;Fernández-Zenoff et al, 2006;Ruiz-González et al, 2013). Certain studies suggest that the degree of infectivity and phage production tends to decrease with the increasing of exposure time and the received amount of UV-B radiation (Jeffrey et al, 1996;Noble & Fuhrman, 1997;Weinbauer et al, 1997;Wilhelm et al, 1998Wilhelm et al, , 2003Cheng et al, 2007). For the study area, a time series of monthly average solar radiation from 1960 to 1999 indicates that higher average levels occur commonly between January and March (548-607 cal cm -2 ; CAR, 2005).…”

Section: Discussionmentioning

confidence: 99%