| A source of carbon dioxide is one of the main requirements for photosynthesis in all plant species. For marine macroalgae, inorganic carbon is readily available in seawater. Intertidal species spend time exposed to air, which has a much lower concentration of inorganic carbon. Several studies recognize the ability of marine macroalgae to accumulate carbon from seawater and from air. The nature of the stored carbon is not well understood. The main objective of this study was to determine the composition of the stored carbon pool in Fucus vesiculosus L. (Phaeophyta). Photosynthesis measurements using an oxygen electrode provided a means to follow the status of the carbon pool. Algal tissue was exposed to air with 1% CO2 and to CO2-free air to build and deplete the carbon store, respectively. After treatment, organic compounds were extracted from the tissue. Because of previous work in terrestrial and marine species, malate, aspartate, and free amino acids were targeted as the most likely candidates for the stored carbon pool. (Abstract shortened by UMI.)... |
