Harmful Algal Blooms involving the dinoflagellate Alexandrium pacificum continue to increase in ecosystems suffering the climate warming and anthropogenic pressure. Changes in the total proteome and physiological traits of the Mediterranean A. pacificum SG C10–3 strain were measured in response to increasing temperature (24 °C, 27 °C, 30 °C) and trace metal contamination (Cu2+, Pb2+, Zn2+, Cd2+). Warming reduced the cell densities and maximal growth rate (μmax), but the strain persisted at 30 °C with more large cells. The polymetallic stress increased cell sizes, reduced cell growth at 24 °C–27 °C and it increased this at 30 °C. Toxin profiles showed a predominance of GTX4 (32–38 %), then C2 (11–34 %) or GTX6 (18–24 %) among the total Paralytic Shellfish Toxins, however these were modified under warming, showing increased contents in GTX1 (among the most toxic), GTX5, C1 and NeoSTX, while dc-NeoSTX and STX (among the most toxic) only appeared at 30 °C. Under polymetallic contamination, warming also increased contents in GTX5 and NeoSTX. In contrast, polymetallic stress, or warming had harmful effects on C2 contents. Proteins were more quantitatively produced by A. pacificum SG C10–3 under warming in accordance with the high levels of up-regulated proteins found in the total proteome in this condition. Polymetallic stress, only or combined with warming, led to low proteomic modifications (1 % or 4 %), whereas warming induced strong 52 % modified proteomic response, mainly based on up-regulated proteins involved in photosynthesis (light harvesting complex protein), carbohydrate metabolism (arylsulfatase) and translation (ribosomal proteins), and with the lesser down-regulated proteins principally associated with the lipid metabolism (type I polyketide synthase). Our results show that warming triggers a strong up-regulated A. pacificum SG C10–3 proteomic response, which, coupled to modified cell sizes and toxin profiles, could help it to withstand stress conditions. This could presage the success of A. pacificum in anthropized ecosystems submitted to global warming in which this dinoflagellate also might be more toxic.

中文翻译：

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变暖和多金属胁迫诱导神经毒性 Alexandrium pacificum 的蛋白质组学和生理学变化，这可能是对全球变化的响应


在遭受气候变暖和人为压力的生态系统中，涉及甲藻 Alexandrium pacificum 的有害藻华继续增加。测量地中海 A. pacificum SG C10-3 菌株的总蛋白质组和生理特性的变化，以响应温度升高 （24 °C、27 °C、30 °C） 和痕量金属污染 （Cu2+、Pb2+、Zn2+、Cd2+）。变暖降低了细胞密度和最大生长速率 （μmax），但菌株在 30 °C 下持续存在，细胞较大。多金属应力增加了细胞大小，在 24 °C–27 °C 时降低了细胞生长，在 30 °C 时增加了细胞生长。 毒素谱显示，在麻痹性贝类毒素中，GTX4 （32-38 %）占主导地位，然后是 C2 （11-34 %） 或 GTX6 （18-24 %），但这些毒素在变暖下被改变，显示 GTX1（毒性最强）、GTX5、C1 和 NeoSTX 中的含量增加，而 dc-NeoSTX 和 STX（毒性最强）仅在 30 °C 时出现。 在多金属污染下，变暖还增加了 GTX5 和 NeoSTX 中的含量。相比之下，多金属应力或变暖对 C2 含量有有害影响。根据在这种情况下总蛋白质组中发现的高水平上调蛋白质，在加热下，A. pacificum SG C10-3 更定量地产生蛋白质。多金属胁迫，单独或与变暖相结合，导致低蛋白质组学修饰（1% 或 4%），而变暖诱导强烈的 52% 修饰蛋白质组学反应，主要基于参与光合作用（光捕获复合物蛋白）、碳水化合物代谢（芳基硫酸酯酶）和翻译（核糖体蛋白）的上调蛋白，以及主要与脂质代谢相关的较低下调蛋白（I 型聚酮合酶）。 我们的结果表明，变暖会触发强烈的上调 A. pacificum SG C10-3 蛋白质组学反应，这与修饰的细胞大小和毒素谱相结合，可以帮助它承受应激条件。这可能预示着 A. pacificum 在受全球变暖影响的人类生态系统中取得成功，其中这种甲藻也可能具有更大的毒性。