Dark survival strategies in benthic diatoms from polar waters

极地浅水区高产的微底栖植物以硅藻为主，它们必须应对深秋和早春之间长时间的黑暗。由于这些生物的黑暗生存策略几乎没有被研究过，因此将在实验室的控制条件下，利用北极kongsjorden和南极Potter Cove丰富的代表性物种，对其潜在机制进行全面而精确的评估。要研究的机制包括最长存续期，这将通过各种细胞生物学标记（大分子组成、超微结构、活力、活性）和遗传标记（参与降解黄藻胺和脂质的功能基因的表达）来确定。此外，将通过测量生长和光合作用来评估再辐照后的恢复能力，以及温度对暗生存潜力的影响。将北极和南极底栖硅藻进行比较，勾勒出具体的响应模式，这些模式可能与这两个地区不同的冷水历史有关，因此与各自分类群对极端低温的不同适应程度有关。如果观测到的北极变暖等环境变化对底栖硅藻的黑暗生存潜力产生负面影响，那么它们作为极地地区重要初级生产者的生态功能可能会大大降低，从而对所有较高营养水平产生影响。

The highly productive microphytobenthos of polar shallow water zones is dominated by diatoms which have to cope with long periods of darkness between late autumn and early spring. Since the dark survival strategies of these organisms are almost unstudied, a comprehensive and precise evaluation of the underlying mechanisms will be carried out under controlled conditions in the laboratory with representative species abundant in the Arctic Kongsfjorden and the Antarctic Potter Cove. The mechanisms to be studied include the maximum survival period which will be determined using various cell biological markers (macromolecular composition, ultrastructure, viability, activity) as well as genetic markers (expression of functional genes involved in the degradation of chrysolaminaran and lipids). In addition, the capability to recover after re-irradiation by measuring growth and photosynthesis, and the effect of temperature on the dark survival potential will be evaluated. Arctic and Antarctic benthic diatoms will be compared to outline specific response patterns which are probably related to the different cold water history of both regions and hence to a different degree of adaptation to extreme low temperatures in the respective taxa. If environmental changes such as the observed Arctic warming are negatively affecting the dark survival potential of benthic diatoms, their ecological function as important primary producers in polar regions may be strongly reduced with consequences for all higher trophic levels.