Abstract. Ocean acidification (OA), which is a major environmental change caused by increasing atmospheric CO₂, has considerable influences on marine phytoplankton. But few studies have investigated interactions of OA and seasonal changes in temperature and photoperiod on marine diatoms. In the present study, a marine diatom Skeletonema costatum was cultured under two different CO₂ levels (LC, 400 μatm; HC, 1000 μatm) and three different combinations of temperature and photoperiod length (8:16 L:D with 5 ℃, 12:12 L:D with 15 ℃, 16:8 L:D with 25 ℃), simulating different seasons in typical temperate oceans, to investigate the combined effects of these factors. The results showed that specific growth rate of S. costatum increased with increasing temperature and daylength. However, OA showed contrasting effects on growth and photosynthesis under different combinations of temperature and daylength: while positive effects of OA were observed under spring and autumn conditions, it significantly decreased growth (11 %) and photosynthesis (21 %) in winter. In addition, low temperature and short daylength decreased the proteins of PSII (D1, CP47 and RubcL) at ambient pCO2 level, while OA alleviated the negative effect. These data indicated that future ocean acidification may show differential effects on diatoms in different cluster of other factors.

中文翻译：

---

肋骨骨骼 藻对海水酸化以及光周期和温度的相互作用的生理响应

摘要。海洋酸化（OA）是由大气CO ₂含量增加引起的主要环境变化，对海洋浮游植物具有相当大的影响。但是很少有研究研究OA和海洋硅藻上温度和光周期的季节性变化的相互作用。在本研究中，在两种不同的CO ₂下培养了一个海洋硅藻骨骼藻。水平（LC，400μatm； HC，1000μatm）以及温度和光周期长度的三种不同组合（5℃时为8:16 L：D，15℃时为12:12 L：D，25时为16：8 L：D ℃），模拟典型温带海洋中的不同季节，以研究这些因素的综合影响。结果表明，随着温度和日长的增加，沙棘的比生长速率增加。然而，在不同温度和日长的组合下，OA对生长和光合作用表现出相反的影响：虽然在春季和秋季条件下观察到OA具有积极作用，但在冬季却显着降低了生长（11％）和光合作用（21％）。此外，低温和短日长在环境降低PSII（D1，CP47和RubcL）的蛋白质pOA减轻了CO2水平的负面影响。这些数据表明，未来海洋酸化可能在其他因素的不同集群中显示出对硅藻的不同影响。