| Autor: |
Christophe Brunet, Nour-Eddine Rmiki, Yves Lemoine, Jacqueline Cabioch |
| Rok vydání: |
1996 |
| Předmět: |
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| Zdroj: |
Fifteenth International Seaweed Symposium ISBN: 9789401072427 |
| DOI: |
10.1007/978-94-009-1659-3_59 |
| Popis: |
Microalgae and macrophytes adapt their pigment content to the environment because excessive light could limit their photosynthetic rate by inducing photoinhibition. Carotenoids participate in the photoadaptative response especially through the operation of xanthophyll cycles (violaxanthin-zeaxanthin or diadinoxanthin-diatoxanthin). An increasing gradient of diatoxanthin in phytoplankton chromophytes is found from the inshore to the offshore waters, less turbid in relation to the different light penetration in seawater. In addition, a nyctemeral cycle is noted, with a suppression of diatoxanthin at night and its accumulation with the increase of the light. Similarly the vertical distribution, on the French Brittany coasts, of several Gracilaria and Gracilariopsis species corresponds to increasing zeaxanthin amounts in the seaweeds living at the upper zones, which are more resistant to photoinhibition as shown by fluorescence and oxygen evolution analysis. An operating xanthophyll cycle should be regarded as a regulatory mechanism involved in stress response for the dissipation of excessive excitation energy through deepoxidated xanthophylls such as zeaxanthin or diatoxanthin. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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