Assessment of potential phagotrophy by pico- and nanophytoplankton in the North Pacific Ocean using flow cytometry
Assessment of potential phagotrophy by pico- and nanophytoplankton in the North Pacific Ocean using flow cytometry
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DOI：
10.3354/ame01892
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发表时间：
2019-01-01
影响因子：
1.4
通讯作者：
Hashihama, Fuminori
中科院分区：
文献类型：
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作者：
Sato, Mitsuhide;Hashihama, Fuminori
混合营养型浮游植物是开放海洋表面微生物群落的重要组成部分。它们可以控制生源物质的代谢平衡和生态地球化学循环。为了确定环境因素，控制专性自养生物在公海的生态繁荣的mixotrophs，我们量化了潜在的mixotrophic picoand nanophytoplankton在整个广泛的区域的北太平洋的纬度和纵向断面，使用流式细胞术和荧光探针LysoTracker绿色相结合。亚热带环流和白令海的潜在混合营养型皮科和微型浮游植物的比例高于周边地区，在亚热带环流的西部地区甚至更高。当混合层内的潜在混合营养体的比例对各种环境参数进行回归时，可溶性活性磷浓度表现出显着的负偏回归系数。这一结果反映了东西梯度在亚热带环流，是与以前的影响，低营养物质的可用性，可以促进兼养浮游植物的吞噬是一致的。出乎意料的是，水的稳定性并没有表现出显着的相关性与潜在的混合营养体的比例，这表明，瞬时的物理参数不会显着影响他们的营养模式。当混合层以下的水的数据集包括在多元回归分析，对可溶性活性磷浓度的显着回归消失。这一结果可能表明浮游植物在更深的海洋环境中的复杂反应。目前的研究结果加强了磷的有效性作为一个控制因素的浮游植物营养生理在亚热带北太平洋的重要性。
Mixotrophic phytoplankton are an important component of the microbial communities of the open ocean surface. They can control the metabolic balance and biogeochemical cycling of biogenic materials. To identify environmental factors that control the ecological prosperity of mixotrophs over obligate autotrophs in the open ocean, we quantified potential mixotrophic picoand nanophytoplankton throughout a wide area of the North Pacific Ocean on latitudinal and longitudinal transects, using a combination of flow cytometry and the fluorescent probe LysoTracker Green. The proportions of potential mixotrophic pico- and nanophytoplankton were higher in the subtropical gyre and Bering Sea than in surrounding areas, and even higher in the western area of the subtropical gyre. When the proportion of potential mixotrophs within the surface mixed layer was regressed against various environmental parameters, soluble reactive phosphorus concentration showed a significant negative partial regression coefficient. This result reflected the east-west gradient in the subtropical gyre and is consistent with previous implications that low nutrient availability can facilitate phagotrophy by mixotrophic phytoplankton. Unexpectedly, water stability did not show a significant correlation with the proportion of potential mixotrophs, which suggests that instantaneous physical parameters do not significantly affect their nutritional mode. When the data sets from water below the mixed layer were included in the multiple regression analysis, the significant regression against soluble reactive phosphorus concentration disappeared. This result may suggest a complex response of phytoplankton in the deeper ocean environment. The present results reinforce the importance of phosphorus availability as a control factor of phytoplankton nutritional physiology in the subtropical North Pacific Ocean.