Ultraviolet radiation negatively affects growth but not food quality of arctic diatoms
Ultraviolet radiation negatively affects growth but not food quality of arctic diatoms
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DOI：
10.4319/lo.2007.52.2.0787
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发表时间：
2007-03-01
影响因子：
4.5
通讯作者：
Hessen, Dag O.
中科院分区：
文献类型：
--
作者：
Leu, Eva;Falk-Petersen, Stig;Hessen, Dag O.
研究了紫外线（280-400 nm）对北极三种优势硅藻（Thalassiosira anarctica var. borealis、Chaetoceros socialis、Bacterosira bathyomphala）。在紫外线照射期间，光合效率被抑制90%，这导致生物量大幅减少。与以前的研究结果相反，总多不饱和脂肪酸（PUFA）的百分比在紫外线照射期间没有下降。相反，B的两种主要PUFA，16：4（n-1）和20：5（n-3）。深脐藻的PUFA含量增加，而南极虾和群居虾的PUFA含量变化不明显。然而，单不饱和脂肪酸16：1（n-7）的含量在所有三个物种大幅下降，在紫外线辐射。由于16：1（n-7）的高浓度通常与有利条件下的指数增长相关，紫外线辐射可能不会直接影响特定类型的脂肪酸;脂肪酸谱反映了藻类生理状态的普遍恶化。在紫外线照射期间，脂肪酸的营养质量没有下降; C：P和N：P比在所有物种中下降了50%，而C：N比在两个物种中略有增加。我们的研究结果表明，紫外线辐射对光合作用和生物量的生产有很强的负面影响，但不对食品质量方面的多不饱和脂肪酸和化学计量。
We studied the short-term effects of ultraviolet radiation (UV radiation, 280-400 nm) on the fatty acid composition and cellular stoichiometry of three dominant arctic diatom species (Thalassiosira antarctica var. borealis, Chaetoceros socialis, Bacterosira bathyomphala) in laboratory experiments. Photosynthetic efficiency during UV irradiation was inhibited 90%, which led to a substantial reduction in biomass. In contrast to results of previous studies, the percentage of total polyunsaturated fatty acids (PUFAs) did not decrease during UV exposure. Instead, the two major PUFAs, 16:4(n-1) and 20:5(n-3), of B. bathyomphala increased, and the PUFA content of T antarctica and C socialis did not change significantly. However, the monounsaturated fatty acid 16:1(n-7) content in all three species substantially decreased during UV radiation. Since high concentrations of 16: 1 (n-7) are usually associated with exponential growth under favorable conditions, UV radiation probably did not affect a specific type of fatty acid directly; the fatty acid profile rather reflected a general deterioration in the algal physiological state. The nutritional quality of the fatty acids did not decrease during UV exposure; the C: P and N:P ratios decreased by 50% in all species, whereas the C: N ratios increased slightly in two species. Our results indicate that UV radiation has strong negative effects on photosynthesis and biomass production, but not on food quality with regard to PUFAs and stoichiometry.