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Dynamics of Fucus serratus thallus photosynthesis and community primary production during emersion across seasons: canopy dampening and biochemical acclimationuse asterix (*) to get italics
Aline Migné, Gwendoline Duong, Dominique Menu, Dominique Davoult & François GévaertPlease use the format "First name initials family name" as in "Marie S. Curie, Niels H. D. Bohr, Albert Einstein, John R. R. Tolkien, Donna T. Strickland"
2021
<p style="text-align: justify;">The brown alga <em>Fucus serratus</em> forms dense stands on the sheltered low intertidal rocky shores of the Northeast Atlantic coast. In the southern English Channel, these stands have proved to be highly productive, particularly during emersion periods. Here, we studied the dampening effect of the canopy cover, associated with physiological and biochemical acclimation processes, that allows this species to withstand emersion stress. The <em>F. serratus </em>community primary production and the photosynthetic performance of thalli were concurrently followed <em>in situ</em>, throughout the midday emersion period, in different seasons and under various weather conditions. In addition, thallus samples were taken at various tidal stages to determine their content in biochemical compounds involved in photoprotective and antioxidant mechanisms. Under high light and temperature, the <em>F. serratus </em>community exhibited high aerial production rates (sometimes exceeding 1 g C m-2 h-1) that never decreased to less than 59% of the initial value during the emersion period. Under mild weather conditions, photosynthesis in thalli at the top of the canopy (measured as the relative electron transport rate) varied in response to changing incident light. Under harsh weather conditions (i.e. high light and temperature), the effective quantum yield of photosystem II (ΦPSII) dramatically decreased in thalli at the top of the canopy, but remained high in thalli at the bottom of or within the canopy. Due to self-shading, photosynthesis was light-limited in thalli in the lowest layer of the canopy, but was effective in thalli in the intermediate layers. Photoinhibition was observed in thalli at the top of the canopy (as a dramatic decrease in the optimal photosynthetic quantum yield Fv/Fm), but not in thalli beneath the canopy. At the end of the emersion period, Fv/Fm was strongly correlated to the relative water content of thalli. The findings from our simultaneous analysis of biochemical and photosynthetic parameters suggest coordination between the xanthophyll and the ascorbate-glutathione cycles that varies with season. An accumulation of hydrogen peroxide was nevertheless observed once, indicating that oxidative stress is nonetheless possible under particularly harsh conditions.</p>
http://doi.org/10.5281/zenodo.5113898You should fill this box only if you chose 'All or part of the results presented in this preprint are based on data'. URL must start with http:// or https://
http://doi.org/10.5281/zenodo.5113898You should fill this box only if you chose 'Scripts were used to obtain or analyze the results'. URL must start with http:// or https://
http://doi.org/10.5281/zenodo.5113898You should fill this box only if you chose 'Codes have been used in this study'. URL must start with http:// or https://
Canopy-forming algae, Intertidal algae, Benthic chamber, PAM fluorescence, Phenolic compounds, Xanthophyll cycle, Antioxidants
Marine ecology
No need for them to be recommenders of PCIEcology. Please do not suggest reviewers for whom there might be a conflict of interest. Reviewers are not allowed to review preprints written by close colleagues (with whom they have published in the last four years, with whom they have received joint funding in the last four years, or with whom they are currently writing a manuscript, or submitting a grant proposal), or by family members, friends, or anyone for whom bias might affect the nature of the review - see the code of conduct
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2021-01-05 16:24:02
Cédric Hubas