Temporal phosphate gradients reveal diverse acclimation responses in phytoplankton phosphate uptake Carlos
Temporal phosphate gradients reveal diverse acclimation responses in phytoplankton phosphate uptake Carlos
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DOI：
10.1038/s41396-019-0473-1
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发表时间：
2019-11-01
期刊：
影响因子：
11
通讯作者：
Bonachela, Juan A.
中科院分区：
文献类型：
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作者：
Caceres, Carlos;Spatharis, Sofie;Bonachela, Juan A.
浮游植物面临着海洋上层动态环境中的营养变化。浮游植物细胞能够通过调整自身的营养吸收系统和代谢，迅速适应营养盐的波动。解开这些驯化反应是弥合浮游植物细胞生理学和群落生态学之间差距的关键步骤。在这里，我们分析了磷（P）的吸收驯化反应沿着不同的时间梯度的硅藻三角褐指藻批培养的动态。我们采用了多学科的方法，结合营养吸收生物测定，转录组学分析和数学模型。我们的结果表明，细胞在响应磷脉冲和强磷限制时都会增加其最大营养吸收速率（V-max）。在经历低细胞内磷水平的细胞中编码不同P转运蛋白的三个基因的上调支持了一些观察到的V-max变化。此外，我们的数学模型再现了经验的V-max模式，包括两种类型的P转运上调中高环境和低细胞内磷水平，分别。我们的研究结果强调存在一个序列的驯化阶段沿着磷酸盐连续体，可以理解为一系列的驯化反应。我们提供了一个新的概念框架，可以有助于整合和理解的动态和广泛多样性的适应浮游植物的反应。
Phytoplankton face environmental nutrient variations that occur in the dynamic upper layers of the ocean. Phytoplankton cells are able to rapidly acclimate to nutrient fluctuations by adjusting their nutrient-uptake system and metabolism. Disentangling these acclimation responses is a critical step in bridging the gap between phytoplankton cellular physiology and community ecology. Here, we analyzed the dynamics of phosphate (P) uptake acclimation responses along different P temporal gradients by using batch cultures of the diatom Phaeodactylum tricornutum. We employed a multidisciplinary approach that combined nutrient-uptake bioassays, transcriptomic analysis, and mathematical models. Our results indicated that cells increase their maximum nutrient-uptake rate (V-max) both in response to P pulses and strong phosphorus limitation. The upregulation of three genes coding for different P transporters in cells experiencing low intracellular phosphorus levels supported some of the observed V-max variations. In addition, our mathematical model reproduced the empirical V-max patterns by including two types of P transporters upregulated at medium-high environmental and low intracellular phosphorus levels, respectively. Our results highlight the existence of a sequence of acclimation stages along the phosphate continuum that can be understood as a succession of acclimation responses. We provide a novel conceptual framework that can contribute to integrating and understanding the dynamics and wide diversity of acclimation responses developed by phytoplankton.