Potential of temperature- and salinity-driven shifts in diatom compatible solute concentrations to impact biogeochemical cycling within sea ice
Potential of temperature- and salinity-driven shifts in diatom compatible solute concentrations to impact biogeochemical cycling within sea ice
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DOI：
10.1525/elementa.421
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发表时间：
2020-06-19
影响因子：
3.9
通讯作者：
Young, Jodi N.
中科院分区：
文献类型：
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作者：
Dawson, Hannah M.;Heal, Katherine R.;Young, Jodi N.
海冰藻类是极地地区初级生产的重要来源，但我们对它们对温度和盐度季节性循环的反应了解有限。使用有针对性的基于液相色谱-质谱的代谢组学方法，我们发现南极海冰硅藻Nitzschia lecointei的无菌培养物在生长条件矩阵中时，其代谢组显示出很大的差异，包括温度-1和4摄氏度，盐度32和41，尽管生长速度变化相对较小。温度比盐度对细胞代谢物池的大小产生更大的影响，尽管含N或S的相容性溶质，2，3-二羟基丙烷-1-磺酸盐（DHPS），甘氨酸甜菜碱（GBT），二甲基磺基丙酸盐（DMSP）和脯氨酸对温度和盐度的反应强烈，表明其控制的复杂性。我们看到脯氨酸对盐度的反应最大（> 4倍）。DHPS，一个很少研究，但潜在的兼容溶质，具有最高的细胞内浓度在所有兼容的溶质类似于85毫米。当比较文化的发现，自然北极海冰硅藻群落，我们发现广泛的重叠代谢产物的配置文件，突出了相关的文化为基础的研究，以探测环境问题。海冰硅藻代谢组和相容性溶质在季节循环中的大的变化可能是海冰内生态地球化学循环的重要组成部分。
Sea-ice algae are an important source of primary production in polar regions, yet we have limited understanding of their responses to the seasonal cycling of temperature and salinity. Using a targeted liquid chromatography-mass spectrometry-based metabolomics approach, we found that axenic cultures of the Antarctic sea-ice diatom, Nitzschia lecointei, displayed large differences in their metabolomes when grown in a matrix of conditions that included temperatures of -1 and 4 degrees C, and salinities of 32 and 41, despite relatively small changes in growth rate. Temperature exerted a greater effect than salinity on cellular metabolite pool sizes, though the N- or S-containing compatible solutes, 2, 3-dihydroxypropane-1-sulfonate (DHPS), glycine betaine (GBT), dimethylsulfoniopropionate (DMSP), and proline responded strongly to both temperature and salinity, suggesting complexity in their control. We saw the largest (> 4-fold) response to salinity for proline. DHPS, a rarely studied but potential compatible solute, had the highest intracellular concentrations among all compatible solutes of similar to 85 mM. When comparing the culture findings to natural Arctic sea-ice diatom communities, we found extensive overlap in metabolite profiles, highlighting the relevance of culture-based studies to probe environmental questions. Large changes in sea-ice diatom metabolomes and compatible solutes over a seasonal cycle could be significant components of biogeochemical cycling within sea ice.