Pronounced gradients of light, photosynthesis and O2 consumption in the tissue of the brown alga Fucus serratus
© 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 207(2015), 3 vom: 30. Aug., Seite 559-69 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2015
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Fucus serratus canopy effects chlorophyll fluorescence macroalgae microsensors photosynthesis scalar irradiance Photosystem II Protein Complex |
| Zusammenfassung: | © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust. Macroalgae live in an ever-changing light environment affected by wave motion, self-shading and light-scattering effects, and on the thallus scale, gradients of light and chemical parameters influence algal photosynthesis. However, the thallus microenvironment and internal gradients remain underexplored. In this study, microsensors were used to quantify gradients of light, O2 concentration, variable chlorophyll fluorescence, photosynthesis and O2 consumption as a function of irradiance in the cortex and medulla layers of Fucus serratus. The two cortex layers showed more efficient light utilization compared to the medulla, calculated both from electron transport rates through photosystem II and from photosynthesis-irradiance curves. At moderate irradiance, the upper cortex exhibited onset of photosynthetic saturation, whereas lower thallus layers exhibited net O2 consumption. O2 consumption rates in light varied with depth and irradiance and were more than two-fold higher than dark respiration. We show that the thallus microenvironment of F. serratus exhibits a highly stratified balance of production and consumption of O2 , and when the frond was held in a fixed position, high incident irradiance levels on the upper cortex did not saturate photosynthesis in the lower thallus layers. We discuss possible photoadaptive responses and consequences for optimizing photosynthetic activity on the basis of vertical differences in light attenuation coefficients |
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| Beschreibung: | Date Completed 26.04.2016 Date Revised 09.01.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.13396 |