Adenylate concentration and energy charge in different thallus regions and after UV radiation in brown, red and green algae

A method was developed to extract adenine nucleotides AMP, ADP, and ATP from marine macroalgal tissue to gain information on the cellular energy charge. Quantification was carried out by high performance liquid chromatography (HPLC). Three species from the rocky shore of the island of Helgoland (German Bight) were examined: Laminaria saccharina (Phaeophyta), Chondrus crispus (Rhodophyta), and Ulva lactuca (Chlorophyta). In L. saccharina and C. crispus, the adenylate energy charge (AEC) was determined in different thallus regions. AEC varied in relation to tissue age and function. Higher AEC values typically occurred in thallus regions with meristematic activity. Furthermore, L. saccharina and U. lactuca were exposed to UV-A and elevated UV-B radiation. The AEC was calculated and the maximal quantum yield of photosystem II (Fv/Fm) was determined as indicators for UV stress. In both species, the AEC remained at high values (0.72 ± 0.04), while Fv/Fm dropped rapidly. The results show that the photosynthesis of the phaeophyte is more resistant to UV radiation than the chlorophyte.

本研究开发了一种从大型海藻组织中提取腺嘌呤核苷酸一磷酸腺苷（AMP）、二磷酸腺苷（ADP）与三磷酸腺苷（ATP）的方法，以获取细胞能荷相关信息。采用高效液相色谱法（HPLC）对上述核苷酸进行定量分析。研究对象选取自黑尔戈兰岛（德国湾）岩岸的3种大型海藻：糖海带（Laminaria saccharina，褐藻门）、皱波角叉菜（Chondrus crispus，红藻门）以及石莼（Ulva lactuca，绿藻门）。针对糖海带与皱波角叉菜，研究者测定了其不同藻体区域的腺苷酸能荷（AEC）。结果显示，AEC值随组织年龄与功能状态发生变化：通常具有分生组织活性的藻体区域，其AEC值更高。此外，将糖海带与石莼分别暴露于UV-A辐射与增强型UV-B辐射环境中，以腺苷酸能荷（AEC）与光系统II最大量子产额（Fv/Fm）作为紫外胁迫的评价指标，分别对AEC进行计算并测定Fv/Fm。两种海藻的AEC值均维持在较高水平（0.72 ± 0.04），但Fv/Fm值均出现快速下降。研究结果表明，褐藻的光合系统对紫外辐射的耐受性强于绿藻。