Temperature and nutrient supply are key factors that control phytoplankton ecophysiology, but their role is commonly investigated in isolation. Their combined effect on resource allocation, photosynthetic strategy, and metabolism remains poorly understood. To characterize the photosynthetic strategy and resource allocation under different conditions, we analyzed the responses of a marine cyanobacterium (Synechococcus PCC 7002) to multiple combinations of temperature and nutrient supply. We measured the abundance of proteins involved in the dark (RuBisCO, rbcL) and light (Photosystem II, psbA) photosynthetic reactions, the content of chlorophyll a, carbon and nitrogen, and the rates of photosynthesis, respiration, and growth. We found that rbcL and psbA abundance increased with nutrient supply, whereas a temperature‐induced increase in psbA occurred only in nutrient‐replete treatments. Low temperature and abundant nutrients caused increased RuBisCO abundance, a pattern we observed also in natural phytoplankton assemblages across a wide latitudinal range. Photosynthesis and respiration increased with temperature only under nutrient‐sufficient conditions. These results suggest that nutrient supply exerts a stronger effect than temperature upon both photosynthetic protein abundance and metabolic rates in Synechococcus sp. and that the temperature effect on photosynthetic physiology and metabolism is nutrient dependent. The preferential resource allocation into the light instead of the dark reactions of photosynthesis as temperature rises is likely related to the different temperature dependence of dark‐reaction enzymatic rates versus photochemistry. These findings contribute to our understanding of the strategies for photosynthetic energy allocation in phytoplankton inhabiting contrasting environments.

中文翻译：

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温度和养分供应对Syechococcus sp。的资源分配，光合策略和代谢速率的影响。

温度和养分供应是控制浮游植物生态生理的关键因素，但通常在隔离中研究其作用。它们对资源分配，光合作用和代谢的综合影响仍然知之甚少。为了表征在不同条件下的光合作用策略和资源分配，我们分析了海洋蓝细菌（Synchococcus PCC 7002）对温度和养分供应的多种组合的响应。我们测量了在黑暗（RuBisCO，rbc L）和光（Photosystem II，psbA）光合作用中涉及的蛋白质丰度，叶绿素a，碳和氮的含量以及光合作用，呼吸和生长的速率。我们发现rbcL和psbA的丰度随着养分的供应而增加，而温度诱导的psbA的增加仅发生在养分充足的处理中。低温和丰富的养分导致RuBisCO丰度增加，这也是我们在很宽的纬度范围内的自然浮游植物组合中观察到的一种模式。仅在营养充足的条件下，光合作用和呼吸作用随温度增加。这些结果表明，养分供应对Synechococcus中的光合蛋白丰度和代谢率均具有比温度更强的作用。sp。温度对光合作用生理和代谢的影响取决于养分。随着温度升高，优先分配给光的资源而不是光合作用的暗反应可能与暗反应酶速率与光化学的温度依赖性不同有关。这些发现有助于我们理解浮游植物居住环境中的光合作用能量分配策略。