Comparative studies on mycosporine-like amino acids, paralytic shellfish toxins and pigment profiles of the toxic dinoflagellates Alexandrium tamarense, A. catenella and A. minutum

Carreto, José I.; Carignan, Mario O.; Montoya, Nora G.

doi:10.3354/meps223049

Cited by 104 publications

(132 citation statements)

References 32 publications

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“…Neale et al 1998, Whitehead & Vernet 2000see Laurion et al 2002 for a comparison table). Carreto et al (2001) found a lower MA concentration in cultures of A. tamarense (6.18 pg cell -1 ), likely related to the low growth irradiance used (65 µmol photons m -2 s -1 ). A total of 7 MAAs were identified, with 1 additional abundant MAA absorbing at 333 nm (M333; Table 1).…”

Section: Resultsmentioning

confidence: 85%

Packaging of mycosporine-like amino acids in dinoflagellates

Laurion¹,

Blouin²,

Roy³

2004

Mar. Ecol. Prog. Ser.

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Synthesis of mycosporine-like amino acids (MAAs) can significantly protect phytoplankton cells against damaging ultraviolet (UV) radiation, depending on the concentration, type and cellular distribution of these UV sunscreens. We addressed the hypothesis that MAAs are concentrated around UV-sensitive organelles for improved efficiency, thereby increasing their 'package effect'. This was investigated for 2 species of MAA-producing dinoflagellates, with comparative analyses of a MAA-free diatom. Spectral absorbance of dinoflagellates suspended in their growth medium was relatively small throughout the MAA-absorbing region despite high concentrations of these compounds (determined by HPLC), suggesting that MAAs are highly packaged in intact cells. The measured in vivo absorbance of suspended and filtered phytoplankton cells revealed an extracellular release of water-soluble MAAs during freezing. The release of MAAs upon thawing enabled the calculation of an MAA packaging index based on the comparison between absorption characteristics before (MAAs inside cells in suspension) and after freezing (MAAs released from cells on thawed filters). Additionally, MAA packaging was evaluated from the reconstruction of absorption spectra from the individual MAA concentration. Consistent with our hypothesis, the results showed that UV absorption was up to 80% lower in the intact cells relative to the MAAs dissolved in solution. These results imply a high degree of MAA packaging in these dinoflagellates, that may increase the protection efficiency for specific cellular targets. KEY WORDS: Package effect · Photoprotection · MAAs · UV-absorbing compounds · Bio-optics · Alexandrium tamarense Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 279: [297][298][299][300][301][302][303] 2004 Pigment packaging has a major influence on the light harvesting efficiency of algal cells (Kirk 1994 and references therein). The absorption efficiency of phytoplankton is a non-linear function of pigment concentration, thylakoid arrangement and cell size (Berner et al. 1989, Nelson et al. 1993. A similar packaging effect for UV sunscreens could be of importance to MAAproducing phytoplankton. For UV sunscreens however, packaging can be viewed as effectiveness, since with equal investments, a large organism would benefit more than a small one. The bio-optical model developed by Garcia-Pichel (1994) indicates that MAAs should only be marginally effective at reducing UV radiation due to the short pathlength characteristic of relatively small phytoplankton cells (assuming a homogeneous cytoplasmic distribution of MAAs). However, the localization of MAAs around UV-sensitive organelles (packaged MAAs) might increase their efficiency, although this has not yet been assessed. MAA packaging has been suggested previously for the colonial prymnesiophyte Phaeocystis antarctica (Davidson & Marchant 1994, Moisan & Mitchell 2001. However, MAA concentrations observed in colonial prymnesiophytes appeared too h...

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Section: Resultsmentioning

confidence: 85%

Packaging of mycosporine-like amino acids in dinoflagellates

Laurion¹,

Blouin²,

Roy³

2004

Mar. Ecol. Prog. Ser.

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“…3h), similar to an unknown compound recently reported in the Baltic Sea ice upon exposure to high UV radiation (Piiparinen et al 2015). Piiparinen et al (2015) speculated the identity of this unknown to be M335/360, a condensation product of shinorine and palythene as reported in Carreto et al (2001). However, the absorption spectrum and chromatographic retention for M335/360 does not match that of U2.…”

Section: Identity Of Maas In Ice-covered Environmentsmentioning

confidence: 75%

Spring production of mycosporine-like amino acids and other UV-absorbing compounds in sea ice-associated algae communities in the Canadian Arctic

Elliott¹,

Mundy²,

Gosselin³

et al. 2015

Mar. Ecol. Prog. Ser.

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Marine phytoplankton are known to produce mycosporine-like amino acids (MAAs) for protection against UV radiation. To assess whether the same strategy applies to sea ice-associated communities, MAAs were measured in algal communities associated with surface melt ponds, sea ice (bottom 3 cm), sea ice−water interface below melt ponds, and underlying seawater in a coastal bay of the Canadian Arctic Archipelago during the spring melt transition from snowcovered to melt pond-covered sea ice. Six UV-absorbing compounds (UVACs) were detected as the spring melt progressed, 3 of which are identified to be shinorine, palythine, and porphyra-334. A fourth UVAC (U1) is most likely palythene. The molecular identities of the other 2 UVACs, U2 and U3, which have an absorption maximum of 363 and 300 nm, respectively, remain to be structurally elucidated. The highest UVAC nominal concentrations were observed in the 3 cm bottom ice under thin snow-covered sites just prior to complete snowmelt. Normalization to chlorophyll a content revealed that the greatest contribution to UV absorption from biota was associated with melt ponds that are exposed to the highest light intensity. These results confirm that Arctic sea ice-associated communities are capable of producing photoprotectants and that spatial and temporal variations in MAA and other UVAC synthesis are affected by snow cover and UV radiation exposure.

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“…Both strains displayed almost identical PSP profiles consisting of approximately 41% C1/2, 57% GXT1/4 and 2% NEO. This profile has been reported several times for Argentinean strains of A. tamarense (Carreto et al, 2001;Montoya et al, 2010). The fact that the field samples displayed a different toxin profile than the local A. tamarense isolates, may be due to a 3-months delay of the sample transport from Argentina to the laboratory in Germany.…”

Section: Phycotoxin Composition and Distribution In Field Plankton Samentioning

confidence: 92%

Analysis of the hydrographic conditions and cyst beds in the San Jorge Gulf, Argentina, that favor dinoflagellate population development including toxigenic species and their toxins

Krock

Borel

Barrera

et al. 2015

Journal of Marine Systems

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The overlay of cooler nutrient enriched Beagle-Magellan water with warmer nutrient depleted shelf water and a strong stratification of the water column in the San Jorge Gulf region, Argentina, coincided with relatively high dinoflagellate abundances in April 2012, up to 34,000 cells L −1 . This dinoflagellate proliferation was dominated by Ceratium spp., but environmental conditions also favored to a lesser amount the occurrence of toxigenic dinoflagellates, such as Alexandrium tamarense and Protoceratium reticulatum, whose toxins were hardly detected in any other areas along the expedition transect of the R/V Puerto Deseado between 38 and 56°S (Ushuaia-Mar del Plata) in March/April 2012. Generally vegetative cells of A. tamarense and P. reticulatum co-occurred with their respective phycotoxins in the water column and their cysts in the upper sediment layers. Two strains of A. tamarense were isolated from the bloom sample and morphologically characterized. Their PSP toxin profiles consisted of C1/2, gonyautoxins 1/4 and to a lesser amount of neosaxitoxin and confirmed earlier data from this region. The ratios between autotrophic picoplankton and heterotrophic bacteria were higher in shelf waters in the north than in Beagle-Magellan waters in the south of San Jorge Gulf.

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Comparative studies on mycosporine-like amino acids, paralytic shellfish toxins and pigment profiles of the toxic dinoflagellates Alexandrium tamarense, A. catenella and A. minutum

Cited by 104 publications

References 32 publications

Packaging of mycosporine-like amino acids in dinoflagellates

Packaging of mycosporine-like amino acids in dinoflagellates

Spring production of mycosporine-like amino acids and other UV-absorbing compounds in sea ice-associated algae communities in the Canadian Arctic

Analysis of the hydrographic conditions and cyst beds in the San Jorge Gulf, Argentina, that favor dinoflagellate population development including toxigenic species and their toxins

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