The transition from winter to spring represents a major shift in the basal energy source for the Antarctic marine ecosystem from lipids and other sources of stored energy to sunlight. Because sea ice imposes a strong control on the transmission of sunlight into the water column during the polar spring, we hypothesized that the timing of the sea ice retreat influences the timing of the transition from stored energy to photosynthesis. To test the influence of sea ice on water column microbial energy utilization we took advantage of unique sea ice conditions in Arthur Harbor, an embayment near Palmer Station on the western Antarctic Peninsula, during the 2015 spring–summer seasonal transition. Over a 5-week period we sampled water from below land-fast sea ice, in the marginal ice zone at nearby Palmer Station B, and conducted an ice removal experiment with incubations of water collected below the land-fast ice. Whole-community metatranscriptomes were paired with lipidomics to better understand how lipid production and utilization was influenced by light conditions. We identified several different phytoplankton taxa that responded similarly to light by the number of genes up-regulated, and in the transcriptional complexity of this response. We applied a principal components analysis to these data to reduce their dimensionality, revealing that each of these taxa exhibited a strikingly different pattern of gene up-regulation. By correlating the changes in lipid concentration to the first principal component of log fold-change for each taxa we could make predictions about which taxa were associated with different changes in the community lipidome. We found that genes coding for the catabolism of triacylglycerol storage lipids were expressed early on in phytoplankton associated with a Fragilariopsis kerguelensis reference transcriptome. Phytoplankton associated with a Corethron pennatum reference transcriptome occupied an adjacent niche, responding favorably to higher light conditions than F. kerguelensis. Other diatom and dinoflagellate taxa had distinct transcriptional profiles and correlations to lipids, suggesting diverse ecological strategies during the polar winter–spring transition.

从冬季到春季的转变代表了南极海洋生态系统基础能源从脂质和其他储能能源到阳光的重大转变。由于极地春季期间，海冰对阳光向水柱的传输施加了强有力的控制，因此我们假设海冰撤退的时机会影响从存储的能量到光合作用的过渡时机。为了测试海冰对水柱微生物能量利用的影响，我们利用了亚瑟港独特的海冰条件，该海冰条件是在2015年春夏季节过渡期间，南极半岛西部帕尔默站附近的一个路口。在五周的时间里，我们在附近的Palmer站B的边缘冰区中，从陆地快速海冰下面取样了水，并进行了除冰实验，对孵化后的陆地冰下的水进行孵化。将整个社区的转录组与脂质组学配对，以更好地了解光照条件如何影响脂质的生产和利用。我们确定了几种不同的浮游植物类群，它们通过上调的基因数量以及这种反应的转录复杂性对光有相似的反应。我们对这些数据进行了主成分分析，以减少它们的维数，从而揭示了这些分类单元中的每一个均表现出明显不同的基因上调模式。通过将脂质浓度的变化与每个分类单元的对数倍数变化的第一主成分相关联，我们可以预测哪些分类单元与社区脂质组的不同变化相关。虎耳草参考转录组。浮游植物与鸡冠花 参考转录组占据了一个邻近的生态位，对更高的光照条件比 格氏。其他硅藻和鞭毛藻类群具有独特的转录谱和与脂质的相关性，这表明在极地冬春季过渡期间的多种生态策略。