Rapid light-induced changes in cell fluorescence and in xanthophyll-cycle pigments of Alexandrium excavatum (Dinophyceae) and Thalassiosira pseudonana (Bacillario-phyceae): a photo-protection mechanism

Demers, Serge; Roy, Suzanne; Gagnon, Richard; Vignault, Ceݩline

doi:10.3354/meps076185

Cited by 187 publications

(140 citation statements)

References 37 publications

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“…Additionally, the variation in the concentrations of diadinoxanthin and diatoxanthin with depth suggests that a xanthophyll cycle is present in these symbiotic dinoflagellates and is involved in photoprotection, as described for free-living dinoflagellates (Demers et al 1991). Differences in pigments between species at the same depth observed in this study demonstrate different mechanisms for acclimatizing to the same underwater light field.…”

Section: Discussionmentioning

confidence: 50%

Light absorption and utilization by colonies of the congeneric hermatypic corals Montastraea faveolata and Montastraea cavernosa

Lesser

Mazel

Phinney

et al. 2000

Limnology & Oceanography

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The congeneric species Montastraea faveolata and Montastraea cavernosa are important hermatypic corals on reefs throughout the Bahamas, Caribbean, and the Florida reef tract that have overlapping bathymetric distributions. However, these congeners differ in their respective abundance at similar depths. The underlying mechanism for these patterns may partly be because of their relative dependence on photoautotrophy versus heterotrophy. The dependence of these two corals on photoautotrophy was examined quantifying the optical properties and productivity of these two species of corals at two different depths in the Dry Tortugas. Maximum surface irradiances in the Dry Tortugas during this study varied from 1,900 to 2,100 mol quanta m Ϫ2 s Ϫ1. Spectral attenuation coefficients calculated from the 1995 and 1996 irradiance data differed by as little as 10% within the visible wavelengths (photosynthetically active radiation [PAR], 400-700 nm), suggesting year-to-year similarities in the optical properties of the overlying water column. Underwater irradiances of PAR were ϳ400 mol quanta m Ϫ2 s Ϫ1 and 25 mol quanta m Ϫ2 s Ϫ1 at 10 m and 18 m, respectively. Significantly lower rates of maximum photosynthesis were observed for samples of M. cavernosa compared with M. faveolata at 10 m and 18 m. For samples of M. faveolata from both depths, the mean chlorophyll-specific absorption (a*) across all PAR wavelengths was greater than that of M. cavernosa. When spectrally corrected for the underwater light field and used to calculate the minimum quantum requirements (1/ m ) of these corals at each depth, we observed that M. faveolata always had higher 1/ m than M. cavernosa (50 versus 18 quanta O 2 Ϫ1 and 39 versus 15 quanta O 2 Ϫ1 at 10 m and 18 m, respectively). M. cavernosa, with its greater pigment concentrations and lower a*, exhibits a significant package effect that results in a smaller functional optical cross section and lower maximum photosynthetic capacities, whereas M. faveolata at the same depths, despite the greater minimum quantum requirements, has a larger functional optical cross section and enhanced absorption of available visible radiation, resulting in a greater maximum photosynthetic capacity. Based on polyp size, corallite structure, and surface area considerations, M. faveolata appears to depend on photoautotrophy versus heterotrophy to a greater extent than its congener, M. cavernosa. Recent data suggest, however, that polyp size alone may not be a good indicator for differences in trophic strategies and that coordinated studies on feeding and productivity in corals are needed to better understand their ecological distributions.

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Section: Discussionmentioning

confidence: 50%

Light absorption and utilization by colonies of the congeneric hermatypic corals Montastraea faveolata and Montastraea cavernosa

Lesser

Mazel

Phinney

et al. 2000

Limnology & Oceanography

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“…Krause & Weis 1991), giving an apparent decrease in biomass. In laboratory low-to-high light studies, nonphotochemical quenching resulted in an initial average rate of change in fluorescence of 4% min -1 (SE = 0.8, n = 13) (from graphs and tables in: Kiefer 1973, Sakshaug et al 1987, Cullen & Lewis 1988, Demers et al 1991, Olaizola et al 1994, Moisan et al 1998. A sudden change from high light to low light is predicted to give the opposite effect: an apparent increase in biomass with a time scale of minutes.…”

Section: Predictionmentioning

confidence: 99%

“…The average rate during summer, although larger, was not significantly different from the laboratory studies (7% min -1 , SE = 1.5; p = 0.15). It may be significant that laboratory studies of non-photochemical quenching generally show the increasing fluorescence response time to be somewhat longer than the decreasing fluorescence response time (Kiefer 1973, Sakshaug et al 1987, Demers et al 1991, Moisan et al 1998, whereas the changes in fluorescence measured in the field were typically symmetric (same rate of increase and decrease during a wave; Figs. 3 & 8).…”

Section: Testmentioning

confidence: 99%

Fluorescence patches in high-frequency internal waves

Lennert‐Cody¹,

Franks²

2002

Mar. Ecol. Prog. Ser.

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“…A specific decrease in the weighting function in the region of absorbance of these compounds would indicate a photoprotective function, as was found for mycosporine-like amino acids (MAAs) in Gymnodinium sanguineum (Neale et al 1998a). Carotenoids also act in a photoprotective function against high irradiance (Demers et al 1991). Organisms have varying abilities to reverse the effects of UV radiation (Karentz et al 1991;Lesser et al 1996).…”

Section: Datementioning

confidence: 99%

Ultraviolet radiation sensitivity of photosynthesis in phytoplankton from an estuarine environment

Banaszak

Neale

2001

Limnology & Oceanography

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We have studied temporal variation in the sensitivity of phytoplankton photosynthesis to inhibition by ultraviolet radiation (UV; 280-400 nm) using biological weighting functions (BWFs) that quantify the biological effect of different wavelengths of UV. Variations in irradiance-dependent BWFs were evaluated for natural phytoplankton assemblages from the Rhode River, a shallow subestuary of the Chesapeake Bay, Maryland, from October 1994 to July 1996. Phytoplankton assemblages were sensitive to UV throughout the year. Rhode River assemblages are inhibited more strongly in the UV-B (280-320 nm), particularly below 300 nm, but there is a significant influence well into the UV-A (320-400 nm). There was no inhibition of phytoplankton photosynthesis by photosynthetically available radiation (400-700 nm), but there was significant seasonal variation in the saturated rate of photosynthesis (P ) and in the light saturation parameter (E s ). There was little variation in seasonal average BWFs through the Ϫ2 ]) and in the spectral shape or relative effect of UV-B versus UV-A, which may be due to changes in species composition, light, temperature, and nutrient availability. Comparison of the most sensitive assemblage (spring) with the least sensitive assemblage (winter) indicates that these BWFs are close to the upper and lower bounds in sensitivity for irradiance-dependent BWFs from all natural and cultured phytoplankton populations. The average, absolute spectral weightings for inhibition of photosynthesis in assemblages from the Rhode River are similar to an average BWF for Antarctic assemblages.

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Rapid light-induced changes in cell fluorescence and in xanthophyll-cycle pigments of Alexandrium excavatum (Dinophyceae) and Thalassiosira pseudonana (Bacillario-phyceae): a photo-protection mechanism

Abstract: Studies of in vivo chlorophyll a (chl a ) fluorescence per cell, measured with a flow cytometer, and the pigment composition of cultured phytoplanktonic cells suggested that the xanthophyll cycle plays a role in the prevention of photoinhibitory damage to the photosynthetic apparatus.

Cited by 187 publications

References 37 publications

Light absorption and utilization by colonies of the congeneric hermatypic corals Montastraea faveolata and Montastraea cavernosa

Light absorption and utilization by colonies of the congeneric hermatypic corals Montastraea faveolata and Montastraea cavernosa

Fluorescence patches in high-frequency internal waves

Ultraviolet radiation sensitivity of photosynthesis in phytoplankton from an estuarine environment

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