کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6304082 | 1618415 | 2014 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Physiological performance of the red alga Stylonema alsidii (Stylonematophyceae) under varying salinities
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم آبزیان
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Physiological performance of the red alga Stylonema alsidii (Stylonematophyceae) under varying salinities Physiological performance of the red alga Stylonema alsidii (Stylonematophyceae) under varying salinities](/preview/png/6304082.png)
چکیده انگلیسی
Stylonema alsidii is a non-florideophycean red alga of a simple morphology and has recently classified as cosmopolitan, suggesting a pronounced physiological ability to successfully colonise new coastal habitats. As for most non-florideophycean red algae, understanding of the general ecology and physiology of this species is, to date, limited. Here, we report S. alsidii from the low-salinity Baltic Sea (habitat salinity: ~Â 25Â SA) for the first time. We compared its salinity stress response with that of a marine isolate (habitat salinity: ~Â 35Â SA) by measuring growth, chlorophyll a (chl a) fluorescence responses, photo-protection capabilities (via NPQ) and low molecular weight carbohydrates (LMWCs) under hypo- and hypersaline conditions. S. alsidii appeared to be a euryhaline species; either isolate grew in a wide salinity range from 5 to 60Â SA and exhibited a growth maximum at full marine 33Â SA. In the marine S. alsidii, the maximum photosystem II (PSII) efficiency (Fv/Fm), the light saturation coefficient of photosynthesis (Ek) and NPQ mechanism were maximal at a full marine salinity, but reduced after exposure to hypo- and hypersaline stress. By contrast, PSII functioning and NPQ mechanisms of the Baltic isolate remained enhanced at low salinities and, thus, reflected an optimised physiological performance at local salinity regimes. However, the results may not allow a differentiation of salinity ecotypes and isolate-specific salinity stress responses could be a result of phenotypic plasticity. The heteroside digeneaside and the polyol sorbitol were the only detectable LMWCs in S. alsidii. In contrast to digeneaside, sorbitol appeared to be involved in processes of osmotic acclimation; this polyol was accumulated with increasing salinities by a factor of 5 (marine isolate) to 10 (Baltic isolate) and, thus, probably functions as organic osmolyte. Euryhaline growth and photosynthesis due to pronounced photo-protective capabilities and the regulation of sorbitol enables S. alsidii to colonise habitats exhibiting large salinity fluctuations (intertidal zones) and along salinity gradients (Baltic Sea) and, thus, can contribute to the wide distribution of this species.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Experimental Marine Biology and Ecology - Volume 460, November 2014, Pages 170-176
Journal: Journal of Experimental Marine Biology and Ecology - Volume 460, November 2014, Pages 170-176
نویسندگان
Udo Nitschke, Ulf Karsten, Anja Eggert,