Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.
Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program in Oceanography, Woods Hole, MA, 02543, USA.
Nat Commun. 2018 Dec 5;9(1):5179. doi: 10.1038/s41467-018-07346-z.
Sunlight is the dominant control on phytoplankton biosynthetic activity, and darkness deprives them of their primary external energy source. Changes in the biochemical composition of phytoplankton communities over diel light cycles and attendant consequences for carbon and energy flux in environments remain poorly elucidated. Here we use lipidomic data from the North Pacific subtropical gyre to show that biosynthesis of energy-rich triacylglycerols (TAGs) by eukaryotic nanophytoplankton during the day and their subsequent consumption at night drives a large and previously uncharacterized daily carbon cycle. Diel oscillations in TAG concentration comprise 23 ± 11% of primary production by eukaryotic nanophytoplankton representing a global flux of about 2.4 Pg C yr. Metatranscriptomic analyses of genes required for TAG biosynthesis indicate that haptophytes and dinoflagellates are active members in TAG production. Estimates suggest that these organisms could contain as much as 40% more calories at sunset than at sunrise due to TAG production.
阳光是浮游植物生物合成活动的主要控制因素，而黑暗则剥夺了它们的主要外部能源。浮游植物群落的生物化学组成在昼夜光周期中的变化以及对环境中碳和能量通量的伴随影响仍未得到充分阐明。在这里，我们利用北太平洋亚热带环流的脂质组学数据表明，真核微微浮游植物在白天合成富含能量的三酰基甘油(TAGs)，然后在晚上消耗这些 TAGs，这驱动了一个以前未被描述的巨大的每日碳循环。TAG 浓度的昼夜振荡占真核微微浮游植物初级生产力的 23±11%，代表着全球约 2.4PgCyr 的通量。用于 TAG 生物合成的基因的宏转录组分析表明，甲藻和腰鞭毛藻是 TAG 生产的活跃成员。估计表明，由于 TAG 的产生，这些生物在日落时的卡路里含量比日出时多 40%。
