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Henrik Pavia - One of the best experts on this subject based on the ideXlab platform.
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Influence of light and nitrogen on the Phlorotannin content of the brown seaweeds Ascophyllum nodosum and Fucus vesiculosus
2013Co-Authors: R(q M. B. Jones, Henrik Pavia, J. M. N. Azevedo, A. I. Neto, A. C. Costa, A. Frias M. Martins, Deep-sea Bioog. Y, Gunilla B. TothAbstract:Phlorotannins, C-based defence compounds in brown seaweeds, show a high degree of spatial and temporal variation within seaweed species. One important model explaining this variation is the Carbon Nutrient Balance Model (CNBM), which states that the relative supply of carbon and limiting nutrients will determine the level of defence compounds in plants. Nitrogen is often co'nsidered to be the limiting nutrient for marine macroalgal growth and the CNBM thus predicts that when the carbon:nitrogen ratio is high, photosynthetically fixed carbon will be allocated to production of Phlorotannins. In the present study, we evaluated the effects of light (i.e. carbon) and nitrogen on the Phlorotannin content of two intertidal brown seaweeds, Ascophyllum nodosum and Fucus vesiculosus. This was done in an observational field study, as well as in a manipulative experiment where plants from habitats with different light regimes were subjected to different nitrogen and light treatments, and their Phlorotannin content was measured after 14 days. The results showed that there was a negative relationship between tissue nitrogen and Phlorotannin content in natural populations of E vesiculosus, but not in A. nodosum. In the short term, the Phlorotannin content in both algal species was not affected by changes in nitrogen availability. Exposure to sunlight had a positive effect on the Phlorotannin content in natural populations of both algal species but, in the manipulative experiment, only E vesiculosus showed a rapid response to changes in light intensities. Plants subjected to sunligh
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Chemical inhibition of barnacle larval settlement by the brown alga Fucus vesiculosus
Marine Ecology Progress Series, 2007Co-Authors: Elisabet Brock, Göran M. Nylund, Henrik PaviaAbstract:The possible importance of larval settlement inhibition by Fucus vesiculosus in explain- ing the low abundance of the barnacle Balanus improvisus on algal fronds compared to adjacent rock was investigated by a combination of field and laboratory studies. A field survey showed that the abundance of adult barnacles was significantly lower on F. vesiculosus than on rocks and settlement preference experiments strongly suggested that settlement avoidance for algal fronds during the natural settlement season was chemically mediated. By using a multi-step approach, whereby both exuded and surface associated metabolites were tested on larval settlement, we further investigated the possible existence of chemical antifouling processes in F. vesiculosus. For exuded metabolites, seawater was conditioned for 1 and 3 h with both submerged and desiccated algae. Surface extracts at natural concentrations and seawater conditioned with submerged algae had no significant effect on larval settlement, although there was a tendency for reduced settlement in the 3 h samples. Sea- water conditioned with desiccated algae consistently inhibited settlement and chemical analyses showed that the mean Phlorotannin level in the water was 31.5 µg ml -1 , which is ca. 30× higher than concentrations previously shown to inhibit barnacle settlement. Seawater conditioned with sub- merged algae had a mean Phlorotannin content of 0.85 µg ml -1 and in samples conditioned for 3 h there was a strong and significant negative relationship between Phlorotannin concentration and larval settlement, suggesting that the Phlorotannin concentration varied around a level inhibitory to barnacle settlement. Altogether, the results from the laboratory experiments strongly suggested that the low larval preference for algae was caused by exudation of waterborne metabolites, primarily Phlorotannins. Finally, field measurements showed that Phlorotannins exuded from F. vesiculosus can under natural conditions reach concentrations inhibitory to settlement of barnacle larvae.
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Intraspecific variation in the Phlorotannin content of the brown alga Ascophyllum nodosum
Phycologia, 2003Co-Authors: Henrik Pavia, Gunilla B. Toth, Annelie Lindgren, Per ÅbergAbstract:Abstract Many brown macroalgae contain substantial concentrations of polyphenolic compounds, known as Phlorotannins. Previous studies have shown that much of the variation in Phlorotannin concentration is correlated with taxonomy and biogeography, but little is known about patterns of variation within species and populations. In this study, we examined intraspecific variation in the Phlorotannin content of the intertidal seaweed Ascophyllum nodosum, by testing for differences within as well as between genetic individuals (genets) and populations, and between algal tissues of similar age from juveniles and adults. The results show that variation in the Phlorotannin content of annual shoots within primary shoots and genets contributes substantially to the total intraspecific variation. This pattern probably indicates that the Phlorotannin content is a highly plastic trait that can be significantly influenced by small-scale variation in extrinsic factors. There were also significant differences in mean phlor...
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Lack of Phlorotannin induction in the kelp Laminaria hyperborea in response to grazing by two gastropod herbivores
Marine Biology, 2002Co-Authors: Gunilla B. Toth, Henrik PaviaAbstract:Phlorotannins (polyphenolic compounds) are found exclusively in brown algae and are commonly regarded as an important component of algal defense against herbivores. The variation in Phlorotannin concentration within and among individual seaweed specimens of the same species can be substantial, and seaweeds may respond to herbivore damage by an increased production of Phlorotannins in order to prevent further herbivory. In the present study, we investigated the natural variation of Phlorotannins in different parts of the kelp Laminaria hyperborea in an observational field survey. We also performed a manipulative induction experiment in which we studied the effect of natural grazing by the patellid limpet Ansates (=Helcion) pellucida and the littorinid snail Lacuna vincta, as well as artificial damage on the production of Phlorotannins in L. hyperborea. There was a large variation in Phlorotannin content both among and within L. hyperborea individuals and populations. The control plants in the induction experiment had a higher Phlorotannin content compared to plants in natural populations, but grazing by A. pellucida or L. vincta, or artificial damage did not induce a higher Phlorotannin concentration in the kelps. Instead, the Phlorotannin content in wounded kelps was significantly lower than in the control plants, possibly due to removal of Phlorotannin-rich outer layers of the kelp thallus, or to an induced compensatory growth response in the L. hyperborea plants. These results imply that L. hyperborea Phlorotannins probably do not function as an inducible chemical defense against A. pellucida and L. vincta, instead grazing by these herbivores decreases the Phlorotannin content of the kelps.
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Removal of dissolved brown algal Phlorotannins using insoluble polyvinylpolypyrrolidone (PVPP).
Journal of Chemical Ecology, 2001Co-Authors: Gunilla B. Toth, Henrik PaviaAbstract:Tannins, a large and diverse group of phenolic secondary metabolites, are common in terrestrial plants and marine brown algae. It is sometimes desirable to remove the tannins from plant or algal extracts, e.g., when isolating enzymes and nucleic acids, when using certain colorimetric methods to quantify the tannin content, or to create reliable controls when using tannins in experimental studies. Insoluble polyvinylpolypyrrolidone (PVPP) can be used to specifically remove tannins from solution. In the present study, we evaluated the effect of different factors (amount of PVPP, number of PVPP treatments, type of solvent, pH, and incubation time) on the PVPP removal of dissolved brown algal Phlorotannins. Our results imply that there is a limited amount of Phlorotannins that can bind to a given amount of PVPP, and that it is preferable to use low quantities of PVPP repeatedly, compared to using fewer treatments with a high amount of PVPP. Furthermore, we found no consistent effect on the removal of Phlorotannins due to solvent type (acetone, methanol, distilled water or filtered seawater). There was a slight decrease in the amount of Phlorotannins removed from extracts with increasing pH when repeatedly treated with PVPP. All Phlorotannins were removed from extracts with pH ≤6.2, and 89% of the initial Phlorotannin content was removed at pH 9.7. These results are compared with previous methodological studies on tannin removal with PVPP. Furthermore, the implications of Phlorotannin removal in analytical and ecological investigations are discussed.
Thomas J Smyth - One of the best experts on this subject based on the ideXlab platform.
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The chemical and antioxidant stability of isolated low molecular weight Phlorotannins.
Food chemistry, 2016Co-Authors: D.a. Kirke, Thomas J Smyth, Dilip K. Rai, Owen Kenny, Dagmar B StengelAbstract:Abstract Due to their high anti-oxidant activity, Phlorotannins represent potential natural alternatives to synthetic preservatives currently used within the food industry. However, their successful integration into food products requires research into their chemical integrity, particularly when selecting appropriate storage conditions. Subsequently, this study aims to investigate the stability of low molecular weight Phlorotannin fractions from Fucus vesiculosus (L.). Powder and aqueous fractions were stored under five different conditions for 10 weeks. Phlorotannin stability was determined using Q-ToF-MS and UPLC-TQD-MS/MS and a DPPH assay. After 10 weeks of storage, fractions suspended in an aqueous matrix underwent oxidation when exposed to continuous atmospheric oxygen and thermal degradation when exposed to a constant temperature of 50 °C, resulting in decreases in radical scavenging activity (p
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profiling of the molecular weight and structural isomer abundance of macroalgae derived Phlorotannins
Marine Drugs, 2015Co-Authors: Natalie Heffernan, Nigel P Brunton, Richard J Fitzgerald, Thomas J SmythAbstract:Phlorotannins are a group of complex polymers of phloroglucinol (1,3,5-trihydroxybenzene) unique to macroalgae. These phenolic compounds are integral structural components of the cell wall in brown algae, but also play many secondary ecological roles such as protection from UV radiation and defense against grazing. This study employed Ultra Performance Liquid Chromatography (UPLC) with tandem mass spectrometry to investigate isomeric complexity and observed differences in Phlorotannins derived from macroalgae harvested off the Irish coast (Fucus serratus, Fucus vesiculosus, Himanthalia elongata and Cystoseira nodicaulis). Antioxidant activity and total phenolic content assays were used as an index for producing Phlorotannin fractions, enriched using molecular weight cut-off dialysis with subsequent flash chromatography to profile Phlorotannin isomers in these macroalgae. These fractions were profiled using UPLC-MS with multiple reaction monitoring (MRM) and the level of isomerization for specific molecular weight Phlorotannins between 3 and 16 monomers were determined. The majority of the low molecular weight (LMW) Phlorotannins were found to have a molecular weight range equivalent to 4–12 monomers of phloroglucinol. The level of isomerization within the individual macroalgal species differed, resulting in substantially different numbers of Phlorotannin isomers for particular molecular weights. F. vesiculosus had the highest number of isomers of 61 at one specific molecular mass, corresponding to 12 phloroglucinol units (PGUs). These results highlight the complex nature of these extracts and emphasize the challenges involved in structural elucidation of these compounds.
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uplc ms profiling of low molecular weight Phlorotannin polymers in ascophyllum nodosum pelvetia canaliculata and fucus spiralis
Metabolomics, 2014Co-Authors: Michelle S Tierney, Anna Solervila, Anna K Croft, Nigel P Brunton, Thomas J SmythAbstract:Phlorotannins are a group of complex polymers, found in particular brown macroalgae, composed solely of the monomer phloroglucinol (1,3,5-trihydroxybenzene). Their structural complexity arises from the number of possible linkage positions between each monomer unit. This study aimed to profile the Phlorotannin metabolite composition and the complexity of isomerisation present in brown macroalgae Ascophyllum nodosum, Pelvetia canaliculata and Fucus spiralis using UPLC-MS utilising a tandem quadrupole mass spectrometer. Phlorotannin-enriched fractions from water and aqueous ethanol extracts were analysed by UPLC-MS performed in multiple reaction monitoring mode to detect molecular ions consistent with the molecular weights of Phlorotannins. Ascophyllum nodosum and P. canaliculata appeared to contain predominantly larger Phlorotannins (degree of polymerisation (DP) of 6–13 monomers) compared to F. spiralis (DP of 4–6 monomers). This is the first report observing the complex chromatographic separation and metabolomic profiling of low molecular weight Phlorotannins consisting of more than ten monomers. Extracted ion chromatograms, for each of the MRM transitions, for each species were analysed to profile the level of isomerisation for specific molecular weights of Phlorotannins between 3 and 16 monomers. The level of Phlorotannin isomerisation within the extracts of the individual macroalgal species differed to some degree, resulting in substantially different numbers of Phlorotannin isomers for particular molecular weights. A similar UPLC-MS/MS separation procedure, as outlined in this study, may be used in the future as a means of screening the metabolite profile of macroalgal extracts, therefore, allowing extract consistency to be monitored for standardisation purposes.
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uplc ms profiling of low molecular weight Phlorotannin polymers in ascophyllum nodosum pelvetia canaliculata and fucus spiralis
Metabolomics, 2014Co-Authors: Michelle S Tierney, Anna Solervila, Anna K Croft, Nigel P Brunton, Thomas J SmythAbstract:Phlorotannins are a group of complex polymers, found in particular brown macroalgae, composed solely of the monomer phloroglucinol (1,3,5-trihydroxybenzene). Their structural complexity arises from the number of possible linkage positions between each monomer unit. This study aimed to profile the Phlorotannin metabolite composition and the complexity of isomerisation present in brown macroalgae Ascophyllum nodosum, Pelvetia canaliculata and Fucus spiralis using UPLC-MS utilising a tandem quadrupole mass spectrometer. Phlorotannin-enriched fractions from water and aqueous ethanol extracts were analysed by UPLC-MS performed in multiple reaction monitoring mode to detect molecular ions consistent with the molecular weights of Phlorotannins. Ascophyllum nodosum and P. canaliculata appeared to contain predominantly larger Phlorotannins (degree of polymerisation (DP) of 6–13 monomers) compared to F. spiralis (DP of 4–6 monomers). This is the first report observing the complex chromatographic separation and metabolomic profiling of low molecular weight Phlorotannins consisting of more than ten monomers. Extracted ion chromatograms, for each of the MRM transitions, for each species were analysed to profile the level of isomerisation for specific molecular weights of Phlorotannins between 3 and 16 monomers. The level of Phlorotannin isomerisation within the extracts of the individual macroalgal species differed to some degree, resulting in substantially different numbers of Phlorotannin isomers for particular molecular weights. A similar UPLC-MS/MS separation procedure, as outlined in this study, may be used in the future as a means of screening the metabolite profile of macroalgal extracts, therefore, allowing extract consistency to be monitored for standardisation purposes.
Michelle S Tierney - One of the best experts on this subject based on the ideXlab platform.
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uplc ms profiling of low molecular weight Phlorotannin polymers in ascophyllum nodosum pelvetia canaliculata and fucus spiralis
Metabolomics, 2014Co-Authors: Michelle S Tierney, Anna Solervila, Anna K Croft, Nigel P Brunton, Thomas J SmythAbstract:Phlorotannins are a group of complex polymers, found in particular brown macroalgae, composed solely of the monomer phloroglucinol (1,3,5-trihydroxybenzene). Their structural complexity arises from the number of possible linkage positions between each monomer unit. This study aimed to profile the Phlorotannin metabolite composition and the complexity of isomerisation present in brown macroalgae Ascophyllum nodosum, Pelvetia canaliculata and Fucus spiralis using UPLC-MS utilising a tandem quadrupole mass spectrometer. Phlorotannin-enriched fractions from water and aqueous ethanol extracts were analysed by UPLC-MS performed in multiple reaction monitoring mode to detect molecular ions consistent with the molecular weights of Phlorotannins. Ascophyllum nodosum and P. canaliculata appeared to contain predominantly larger Phlorotannins (degree of polymerisation (DP) of 6–13 monomers) compared to F. spiralis (DP of 4–6 monomers). This is the first report observing the complex chromatographic separation and metabolomic profiling of low molecular weight Phlorotannins consisting of more than ten monomers. Extracted ion chromatograms, for each of the MRM transitions, for each species were analysed to profile the level of isomerisation for specific molecular weights of Phlorotannins between 3 and 16 monomers. The level of Phlorotannin isomerisation within the extracts of the individual macroalgal species differed to some degree, resulting in substantially different numbers of Phlorotannin isomers for particular molecular weights. A similar UPLC-MS/MS separation procedure, as outlined in this study, may be used in the future as a means of screening the metabolite profile of macroalgal extracts, therefore, allowing extract consistency to be monitored for standardisation purposes.
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uplc ms profiling of low molecular weight Phlorotannin polymers in ascophyllum nodosum pelvetia canaliculata and fucus spiralis
Metabolomics, 2014Co-Authors: Michelle S Tierney, Anna Solervila, Anna K Croft, Nigel P Brunton, Thomas J SmythAbstract:Phlorotannins are a group of complex polymers, found in particular brown macroalgae, composed solely of the monomer phloroglucinol (1,3,5-trihydroxybenzene). Their structural complexity arises from the number of possible linkage positions between each monomer unit. This study aimed to profile the Phlorotannin metabolite composition and the complexity of isomerisation present in brown macroalgae Ascophyllum nodosum, Pelvetia canaliculata and Fucus spiralis using UPLC-MS utilising a tandem quadrupole mass spectrometer. Phlorotannin-enriched fractions from water and aqueous ethanol extracts were analysed by UPLC-MS performed in multiple reaction monitoring mode to detect molecular ions consistent with the molecular weights of Phlorotannins. Ascophyllum nodosum and P. canaliculata appeared to contain predominantly larger Phlorotannins (degree of polymerisation (DP) of 6–13 monomers) compared to F. spiralis (DP of 4–6 monomers). This is the first report observing the complex chromatographic separation and metabolomic profiling of low molecular weight Phlorotannins consisting of more than ten monomers. Extracted ion chromatograms, for each of the MRM transitions, for each species were analysed to profile the level of isomerisation for specific molecular weights of Phlorotannins between 3 and 16 monomers. The level of Phlorotannin isomerisation within the extracts of the individual macroalgal species differed to some degree, resulting in substantially different numbers of Phlorotannin isomers for particular molecular weights. A similar UPLC-MS/MS separation procedure, as outlined in this study, may be used in the future as a means of screening the metabolite profile of macroalgal extracts, therefore, allowing extract consistency to be monitored for standardisation purposes.
Gunilla B. Toth - One of the best experts on this subject based on the ideXlab platform.
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Influence of light and nitrogen on the Phlorotannin content of the brown seaweeds Ascophyllum nodosum and Fucus vesiculosus
2013Co-Authors: R(q M. B. Jones, Henrik Pavia, J. M. N. Azevedo, A. I. Neto, A. C. Costa, A. Frias M. Martins, Deep-sea Bioog. Y, Gunilla B. TothAbstract:Phlorotannins, C-based defence compounds in brown seaweeds, show a high degree of spatial and temporal variation within seaweed species. One important model explaining this variation is the Carbon Nutrient Balance Model (CNBM), which states that the relative supply of carbon and limiting nutrients will determine the level of defence compounds in plants. Nitrogen is often co'nsidered to be the limiting nutrient for marine macroalgal growth and the CNBM thus predicts that when the carbon:nitrogen ratio is high, photosynthetically fixed carbon will be allocated to production of Phlorotannins. In the present study, we evaluated the effects of light (i.e. carbon) and nitrogen on the Phlorotannin content of two intertidal brown seaweeds, Ascophyllum nodosum and Fucus vesiculosus. This was done in an observational field study, as well as in a manipulative experiment where plants from habitats with different light regimes were subjected to different nitrogen and light treatments, and their Phlorotannin content was measured after 14 days. The results showed that there was a negative relationship between tissue nitrogen and Phlorotannin content in natural populations of E vesiculosus, but not in A. nodosum. In the short term, the Phlorotannin content in both algal species was not affected by changes in nitrogen availability. Exposure to sunlight had a positive effect on the Phlorotannin content in natural populations of both algal species but, in the manipulative experiment, only E vesiculosus showed a rapid response to changes in light intensities. Plants subjected to sunligh
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Intraspecific variation in the Phlorotannin content of the brown alga Ascophyllum nodosum
Phycologia, 2003Co-Authors: Henrik Pavia, Gunilla B. Toth, Annelie Lindgren, Per ÅbergAbstract:Abstract Many brown macroalgae contain substantial concentrations of polyphenolic compounds, known as Phlorotannins. Previous studies have shown that much of the variation in Phlorotannin concentration is correlated with taxonomy and biogeography, but little is known about patterns of variation within species and populations. In this study, we examined intraspecific variation in the Phlorotannin content of the intertidal seaweed Ascophyllum nodosum, by testing for differences within as well as between genetic individuals (genets) and populations, and between algal tissues of similar age from juveniles and adults. The results show that variation in the Phlorotannin content of annual shoots within primary shoots and genets contributes substantially to the total intraspecific variation. This pattern probably indicates that the Phlorotannin content is a highly plastic trait that can be significantly influenced by small-scale variation in extrinsic factors. There were also significant differences in mean phlor...
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Lack of Phlorotannin induction in the kelp Laminaria hyperborea in response to grazing by two gastropod herbivores
Marine Biology, 2002Co-Authors: Gunilla B. Toth, Henrik PaviaAbstract:Phlorotannins (polyphenolic compounds) are found exclusively in brown algae and are commonly regarded as an important component of algal defense against herbivores. The variation in Phlorotannin concentration within and among individual seaweed specimens of the same species can be substantial, and seaweeds may respond to herbivore damage by an increased production of Phlorotannins in order to prevent further herbivory. In the present study, we investigated the natural variation of Phlorotannins in different parts of the kelp Laminaria hyperborea in an observational field survey. We also performed a manipulative induction experiment in which we studied the effect of natural grazing by the patellid limpet Ansates (=Helcion) pellucida and the littorinid snail Lacuna vincta, as well as artificial damage on the production of Phlorotannins in L. hyperborea. There was a large variation in Phlorotannin content both among and within L. hyperborea individuals and populations. The control plants in the induction experiment had a higher Phlorotannin content compared to plants in natural populations, but grazing by A. pellucida or L. vincta, or artificial damage did not induce a higher Phlorotannin concentration in the kelps. Instead, the Phlorotannin content in wounded kelps was significantly lower than in the control plants, possibly due to removal of Phlorotannin-rich outer layers of the kelp thallus, or to an induced compensatory growth response in the L. hyperborea plants. These results imply that L. hyperborea Phlorotannins probably do not function as an inducible chemical defense against A. pellucida and L. vincta, instead grazing by these herbivores decreases the Phlorotannin content of the kelps.
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Removal of dissolved brown algal Phlorotannins using insoluble polyvinylpolypyrrolidone (PVPP).
Journal of Chemical Ecology, 2001Co-Authors: Gunilla B. Toth, Henrik PaviaAbstract:Tannins, a large and diverse group of phenolic secondary metabolites, are common in terrestrial plants and marine brown algae. It is sometimes desirable to remove the tannins from plant or algal extracts, e.g., when isolating enzymes and nucleic acids, when using certain colorimetric methods to quantify the tannin content, or to create reliable controls when using tannins in experimental studies. Insoluble polyvinylpolypyrrolidone (PVPP) can be used to specifically remove tannins from solution. In the present study, we evaluated the effect of different factors (amount of PVPP, number of PVPP treatments, type of solvent, pH, and incubation time) on the PVPP removal of dissolved brown algal Phlorotannins. Our results imply that there is a limited amount of Phlorotannins that can bind to a given amount of PVPP, and that it is preferable to use low quantities of PVPP repeatedly, compared to using fewer treatments with a high amount of PVPP. Furthermore, we found no consistent effect on the removal of Phlorotannins due to solvent type (acetone, methanol, distilled water or filtered seawater). There was a slight decrease in the amount of Phlorotannins removed from extracts with increasing pH when repeatedly treated with PVPP. All Phlorotannins were removed from extracts with pH ≤6.2, and 89% of the initial Phlorotannin content was removed at pH 9.7. These results are compared with previous methodological studies on tannin removal with PVPP. Furthermore, the implications of Phlorotannin removal in analytical and ecological investigations are discussed.
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Lack of Phlorotannin induction in the brown seaweed Ascophyllum nodosum in response to increased copper concentrations
Marine Ecology Progress Series, 2000Co-Authors: Gunilla B. Toth, Henrik PaviaAbstract:Heavy metal resistance in plants and algae may involve an internal detoxification mechanism, where toxic metal ions are chelated to substances that are stored in special compartments within the cells. Phlorotannins (brown algal polyphenolics) are strong chelators to heavy metals in solution and are found in special compartments (physodes) within the cells, and have therefore been suggested to function as an internal detoxification mechanism in brown seaweeds. Phlorotannins are also believed to function as a chemical defence against herbivory and UV radiation, and the production of Phlorotannins has been shown to be induced by increased intensities of these factors. In the present study, we investigated the possible role of Phlorotannins as an inducible and internal detoxification mechanism in the brown seaweed Ascophyllum nodosum (L.) Le Jol., in response to increased copper (Cu) concentrations in the surrounding water. The Phlorotannin content, tissue Cu content and growth of Cu-exposed seaweeds from areas with different levels of contamination were compared in an observational field study and 2 manipulative induction experiments. The Phlorotannin content and growth of the seaweeds were not affected by high Cu concentrations, although A. nodosum plants exposed to high Cu levels accumulated high concentrations of Cu in their tissues. The accumulated Cu was not specifically associated with Phlorotannins, since only a small part of the total tissue Cu content of the seaweeds was found in the extracted Phlorotannin fractions. The results of the present study show that Phlorotannin production in A. nodosum is not induced by high Cu concentrations and that, although plants accumulate high levels of Cu in the tissues, binding of Cu to Phlorotannins is probably not an important internal detoxification mechanism in A. nodosum. Since plants were not negatively affected by elevated Cu levels in terms of growth, substances other than Phlorotannins are probably more important in the metal resistance mechanism of A. nodosum.
Veijo Jormalainen - One of the best experts on this subject based on the ideXlab platform.
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Variation of Phlorotannins among three populations of Fucus vesiculosus as revealed by HPLC and colorimetric quantification.
Journal of chemical ecology, 2007Co-Authors: Riitta Koivikko, J. K. Eränen, Jyrki Loponen, Veijo JormalainenAbstract:In ecological studies, Phlorotannins have conventionally been quantified as a group with similar functionality. Since this group consists of oligo- and polymers, the quantification of their pooled contents alone may not sufficiently describe the variation of these metabolites. Genetic variation, plastic responses to environment, and the ecological functions of separate Phlorotannin oligo- and polymers may differ. Two analyses, i.e., the colorimetric Folin-Ciocalteu assay and a normal-phase high-performance liquid chromatographic (HPLC) method were used to study genetic and environmental variation in Phlorotannins of the brown alga Fucus vesiculosus (L.). The colorimetric method provides the total Phlorotannin content, the latter a profile of 14 separate traces from the phenolic extract that represent an individual or groups of Phlorotannins. We reared the algae that originated from three separate populations in a common garden for 3 months under ambient and enriched-nutrient availability and found that they differed in both their total Phlorotannin content and in Phlorotannin profiles. Some individual traces of the profiles separated the populations more clearly than the colorimetric assay. Although nutrient enrichment decreased total Phlorotannin content, it did not show a significant influence on the Phlorotannin profile. This implies that plastic responses of compounds other than Phlorotannins may interfere with the determination of total Phlorotannins. However, the Phlorotannin profile and the total content showed genetic variation among local populations of F. vesiculosus; therefore, Phlorotannins may respond to natural selection and evolve both quantitatively and qualitatively.
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polar extracts of the brown alga fucus vesiculosus l reduce assimilation efficiency but do not deter the herbivorous isopod idotea baltica pallas
Journal of Experimental Marine Biology and Ecology, 2005Co-Authors: Veijo Jormalainen, Tuija Honkanen, Outi Vesakoski, Riitta KoivikkoAbstract:Abstract Plant secondary metabolites provide resistance against herbivory if they are capable of decreasing herbivore performance or deterring feeding. Here we test the effects of Phlorotannin-containing polar extracts from the brown alga Fucus vesiculosus on the assimilation efficiency and feeding preferences of the herbivorous isopod Idotea baltica . We test the effects separately for each sex of the isopod to test the hypothesis that the digestive efficiencies of the sexes may have diverged. Phlorotannin-containing polar extracts were incorporated into an agar-based artificial food in varying amounts. We also varied the quality of the food, using high-quality food containing animal proteins and low-quality food containing only algal material. The total assimilation efficiency as well as the assimilation efficiencies of carbon and nitrogen decreased with an increasing concentration of Phlorotannin-containing extracts. The negative effects on carbon and nitrogen assimilation were higher when extracts were incorporated in the high-quality food. Females were consistently more efficient than males in all assimilation measures; there were no interactions between sex and food quality or Phlorotannin concentration, suggesting that the digestive efficiency of the sexes had diverged but that the two sexes responded similarly to Phlorotannin enriched artificial food. Although Phlorotannin-containing extracts were harmful to performance, they did not deter feeding in preference tests. On the contrary: the isopods preferred the food containing more Phlorotannins, suggesting that Phlorotannins may act as cues in host recognition. Thus Phlorotannins were inefficient deterrents, and I. baltica seems to be adapted to utilizing Phlorotannin-containing foods despite their detrimental effects on assimilation. We suggest that F. vesiculosus provides a predation refuge and temporal constancy in availability for I. baltica , both of which select for the ability to utilize it as a food. Phlorotannin-containing polar extracts from F. vesiculosus are still harmful digestibility reducers, and may thereby prevent complete specialization and generate selection for utilization of a wider host range.
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Contents of soluble, cell-wall-bound and exuded Phlorotannins in the brown alga Fucus vesiculosus, with implications on their ecological functions.
Journal of chemical ecology, 2005Co-Authors: Riitta Koivikko, Tuija Honkanen, Jyrki Loponen, Veijo JormalainenAbstract:Phlorotannins are ubiquitous secondary metabolites in brown algae that are phenotypically plastic and suggested to have multiple ecological roles. Traditionally, Phlorotannins have been quantified as total soluble Phlorotannins. Here, we modify a quantification procedure to measure, for the first time, the amount of cell-wall-bound Phlorotannins. We also optimize the quantification of soluble Phlorotannins. We use these methods to study the responses of soluble and cell-wall-bound Phlorotannin to nutrient enrichment in growing and nongrowing parts of the brown alga Fucus vesiculosus. We also examine the effects of nutrient shortage and herbivory on the rate of Phlorotannin exudation. Concentrations of cell-wall-bound Phlorotannins were much lower than concentrations of soluble Phlorotannins; we also found that nutrient treatment over a period of 41 days affected only soluble Phlorotannins. Concentrations of each Phlorotannin type correlated positively between growing and nongrowing parts of individual seaweeds. However, within nongrowing thalli, soluble and cell-wall-bound Phlorotannins were negatively correlated, whereas within growing thalli there was no correlation. Phlorotannins were exuded from the thallus in all treatments. Herbivory increased exudation, while a lack of nutrients had no effect on exudation. Because the amount of cell-wall-bound Phlorotannins is much smaller than the amount of soluble Phlorotannins, the major function of Phlorotannins appears to be a secondary one.
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Variation in natural selection for growth and Phlorotannins in the brown alga Fucus vesiculosus
Journal of evolutionary biology, 2004Co-Authors: Veijo Jormalainen, Tuija HonkanenAbstract:Directional selection for plant traits associated with resistance to herbivory tends to eliminate genetic variation in such traits. On the other hand, balancing selection arising from trade-offs between resistance and growth or spatially variable selection acts against the elimination of genetic variation. We explore both the amount of genetic variation and variability of natural selection for growth and concentration of phenolic secondary compounds, Phlorotannins, in the brown alga Fucus vesiculosus. We measured variation in selection at two growing depths and two levels of nutrient availability in algae that had faced two kinds of past growing environments. Genetic variation was low for growth but high for Phlorotannins. The form and strength of selection for both focal traits depended on the past growing environment of the algae. We found strong directional selection for growth rate in algae previously subjected to higher ultraviolet radiation, but not in algae previously subjected to higher nutrient availability. Stabilizing selection for growth occurred especially in the deep growing environment. Selection for Phlorotannins was generally weak, but in some past-environment–current-environment combinations we detected either directional selection against Phlorotannins or stabilizing selection. Thus, Phlorotannins are not selectively neutral but affect the fitness of F. vesiculosus. In particular, there may be a fitness cost of producing Phlorotannins, but the realization of such a cost varies from one environment to another. Genetic correlations between selective environments were high for growth but nonexistent for Phlorotannins, emphasizing the high phenotypic plasticity of Phlorotannin production. The highly heterogeneous selection, including directional, stabilizing, and spatially variable selection as well as temporal change in selection due to responses to past environmental conditions, probably maintains a high amount of genetic variation in Phlorotannins. Such variation provides the potential for rapid evolutionary response of Phlorotannins under directional selection.
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Induction of Phlorotannin production in a brown alga: defense or resource dynamics?
Oikos, 2003Co-Authors: Veijo Jormalainen, Tuija Honkanen, Riitta Koivikko, J. K. EränenAbstract:Increase of phenolic secondary metabolites, Phlorotannins, in brown algae due to gastropod grazing has been interpreted as an anti-herbivore adaptation. Here we tested whether such a response could be due to changes in truly available resources for the alga, not by the grazing activity of snails as such. We allowed two species of snails, Theodoxus fluviatilis and Physa fontinalis to graze on Fucus vesiculosus. These species feed on epibiota and particulate matter on the thallus but do not eat the thallus of F. vesiculosus. We further simulated snail grazing by nutrient enhancement, removal of epibiota and by a combination of the two. Manipulations of nutrient and light availability revealed the crucial role of epibiota in mediating resource availability for F. vesiculosus. Nutrient enhancement alone increased epibiota and decreased Phlorotannins. Cleaning the thallus resulted in increased growth, and together with nutrient enhancement also in a trade-off with Phlorotannins. Presence of T. fluviatilis on the thallus induced Phlorotannin production, a response differing from the simulations of snail grazing. However, we suggest that the increase in Phlorotannins may not be an induced defense but rather a consequence of a specific way of resource manipulation by this snail species. T. fluviatilis removes hyaline hairs that facilitate nutrient uptake. P. fontinalis did not remove hyaline hairs and the response of the alga to its grazing was similar to the treatment where we mechanically removed epibiota suggesting that cleaning of the thallus is the major mechanism how this snail species affects F. vesiculosus. Genetic variation in Phlorotannin concentrations highly exceeded the induced responses of simulated or real snail grazing. This casts doubt for the efficiency of induced Phlorotannin production to act as a defense, but is not contradictory with the interpretation of Phlorotannins responding to variation in resource availability.