Olischläger Mark, Iñiguez Concepción, Koch Kristina, Wiencke Christian, Gordillo Francisco Javier López
Department of Functional Ecology, Alfred-Wegener-Institute, Helmholtz Center for Marine and Polar Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
Department of Ecology, Faculty of Sciences, University of Malaga, Bulevar Louis Pasteur s/n, 29010, Malaga, Spain.
Planta. 2017 Jan;245(1):119-136. doi: 10.1007/s00425-016-2594-3. Epub 2016 Sep 21.
The Arctic population of the kelp Saccharina latissima differs from the Helgoland population in its sensitivity to changing temperature and CO levels. The Arctic population does more likely benefit from the upcoming environmental scenario than its Atlantic counterpart. The previous research demonstrated that warming and ocean acidification (OA) affect the biochemical composition of Arctic (Spitsbergen; SP) and cold-temperate (Helgoland; HL) Saccharina latissima differently, suggesting ecotypic differentiation. This study analyses the responses to different partial pressures of CO (380, 800, and 1500 µatm pCO) and temperature levels (SP population: 4, 10 °C; HL population: 10, 17 °C) on the photophysiology (O production, pigment composition, D1-protein content) and carbon assimilation [Rubisco content, carbon concentrating mechanisms (CCMs), growth rate] of both ecotypes. Elevated temperatures stimulated O production in both populations, and also led to an increase in pigment content and a deactivation of CCMs, as indicated by C isotopic discrimination of algal biomass (ε ) in the HL population, which was not observed in SP thalli. In general, pCO effects were less pronounced than temperature effects. High pCO deactivated CCMs in both populations and produced a decrease in the Rubisco content of HL thalli, while it was unaltered in SP population. As a result, the growth rate of the Arctic ecotype increased at elevated pCO and higher temperatures and it remained unchanged in the HL population. Ecotypic differentiation was revealed by a significantly higher O production rate and an increase in Chl a, Rubisco, and D1 protein content in SP thalli, but a lower growth rate, in comparison to the HL population. We conclude that both populations differ in their sensitivity to changing temperatures and OA and that the Arctic population is more likely to benefit from the upcoming environmental scenario than its Atlantic counterpart.
海带（Saccharina latissima）的北极种群与黑尔戈兰岛种群在对温度和二氧化碳水平变化的敏感性方面存在差异。北极种群比其大西洋对应种群更有可能从即将到来的环境情景中受益。先前的研究表明，变暖和海洋酸化（OA）对北极（斯匹次卑尔根群岛；SP）和寒温带（黑尔戈兰岛；HL）海带的生化组成影响不同，这表明存在生态型分化。本研究分析了两种生态型在不同二氧化碳分压（380、800和1500 μatm pCO₂）和温度水平（SP种群：4、10℃；HL种群：10、17℃）下对光生理学（氧气产生、色素组成、D1蛋白含量）和碳同化[核酮糖-1,5-二磷酸羧化酶含量、碳浓缩机制（CCM）、生长速率]的响应。温度升高刺激了两个种群的氧气产生，还导致色素含量增加以及CCM失活，如HL种群中藻类生物量的碳同位素判别（ε）所示，而在SP藻体中未观察到这种情况。总体而言，pCO₂的影响不如温度的影响明显。高pCO₂使两个种群的CCM失活，并导致HL藻体中核酮糖-1,5-二磷酸羧化酶含量下降，而SP种群中该含量未改变。结果，北极生态型在高pCO₂和较高温度下生长速率增加，而HL种群的生长速率保持不变。与HL种群相比，SP藻体中氧气产生速率显著更高，叶绿素a、核酮糖-1,5-二磷酸羧化酶和D1蛋白含量增加，但生长速率较低，这揭示了生态型分化。我们得出结论，两个种群对温度变化和OA的敏感性不同，并且北极种群比其大西洋对应种群更有可能从即将到来的环境情景中受益。
