Photorepair activity and protective compounds in two freshwater zooplankton species (Daphnia menucoensis and Metacyclops mendocinus) from Patagonia, Argentina
Photorepair activity and protective compounds in two freshwater zooplankton species (Daphnia menucoensis and Metacyclops mendocinus) from Patagonia, Argentina
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DOI：
10.1039/b208145h
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发表时间：
2002-12-01
影响因子：
3.1
通讯作者：
Helbling, E. Walter
中科院分区：
文献类型：
--
作者：
Goncalves, Rodrigo J.;Villafane, Virginia E.;Helbling, E. Walter
紫外线-B辐射（UV-B，280-315 nm）的影响，枝水蚤menucoensis Paggi和桡足类Metacyclops mendocinus（Wierzejski）的实验，旨在评估光修复机制的有效性和紫外线吸收化合物的作用。在这两个物种中，UV-B在剂量接近40 kJ/m（-2）或更高时造成显著死亡。然而，在较低的UV-B剂量下，在M中没有检测到显著的死亡率。mendocinus;此外，这个物种似乎有一个阈值，低于该阈值没有UV-B诱导的死亡率是确定的。D.而menucoensis则对UV-B非常敏感，当剂量低至10 kJ·m（-2）时，menucoensis的死亡率高达15%（p < 0.05）。两个物种都表现出高效率的光修复UV-B诱导的DNA分子损伤，当物种暴露于可见光辐射，PAR（55 W m（-2）），除了UV-B的死亡率显着下降。M. mendocinus对UV-B辐射的敏感性高于D. menucoensis也可能与类菌孢素氨基酸，MAA（即，shinorine和porphyra-334）和类胡萝卜素，这将增加桡足类的适应优势。
The impact of ultraviolet-B radiation (UV-B, 280-315 nm) on the cladoceran Daphnia menucoensis Paggi and the copepod Metacyclops mendocinus (Wierzejski) was determined in experiments designed to evaluate the effectiveness of the photorepair mechanism and the role of UV-absorbing compounds. In both species UV-B caused significant mortality at doses of similar to 40 kJ m(-2) or higher. At lower UV-B doses, however, no significant mortality was detected in M. mendocinus; moreover, this species seems to have a threshold below which no UV-B induced mortality is determined. D. menucoensis, on the other hand, was very sensitive to UV-B, and significant mortality of 15% (p < 0.05) was observed when doses were as low as 10 kJ m(-2). Both species showed high efficiency for photorepairing UV-B-induced damage to the DNA molecule, with a significant decrease of mortality when the species were exposed to visible radiation, PAR (55 W m(-2)), in addition to UV-B. The higher resistance of M. mendocinus to UV-B as compared to that of D. menucoensis might be also related to the presence of mycosporine-like amino acids, MAAs (i.e., shinorine and porphyra-334), and carotenoids, which would add an adaptive advantage to the copepod.