Effects of an experimental heat wave on fatty acid composition in two Mediterranean seagrass species
Effects of an experimental heat wave on fatty acid composition in two Mediterranean seagrass species
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DOI：
10.1016/j.marpolbul.2017.12.057
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发表时间：
2018-09-01
影响因子：
5.8
通讯作者：
Ruiz, Juan M.
中科院分区：
文献类型：
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作者：
Beca-Carretero, Pedro;Guiheneuf, Freddy;Ruiz, Juan M.
全球变暖正在成为全世界陆地和海洋物种最严重的威胁之一。这项研究评估了养殖中模拟变暖事件对两种海草物种（Posidonia oceanica 和 Cymodocea nodosa）的影响，这两种海草在地中海沿海生态系统中发挥着关键作用。在适应不同原位温度条件的每个物种的两个地理种群的样本中评估了作为关键代谢指标的脂肪酸的变化。比较了自然群体中的 C. nodosa 和 P. oceanica 以及在培养物中暴露于热应激后的总脂肪酸 (TFA) 含量和组成。热暴露后，C. nodosa 和 P. oceanica 个体适应了原地较冷的温度，积累的 TFA 明显多于对照。对于这两个物种，热处理后多不饱和脂肪酸（PUFA）的比例下降，而饱和脂肪酸（SFA）的比例显着增加。这些结果强调，生活在原地最高温度下的这两个物种的种群都更耐热，并且通过更快地重新调整其脂质成分来表现出更大的应对热应激的能力。最后，将海草暴露在温暖条件下可能会导致 PUFA/SFA 比率下降，这可能对其营养价值产生负面影响，并对下一个营养级的健康状态产生重要影响。
Global warming is emerging as one of the most critical threats to terrestrial and marine species worldwide. This study assessed the effects of simulated warming events in culture on two seagrass species, Posidonia oceanica and Cymodocea nodosa, which play a key role in coastal ecosystems of the Mediterranean Sea. Changes in fatty acids as key metabolic indicators were assessed in specimens from two geographical populations of each species adapted to different in situ temperature regimes. Total fatty acid (TFA) content and composition were compared in C. nodosa and P. oceanica from natural populations and following exposure to heat stress in culture. After heat exposure, individuals of C. nodosa and P. oceanica adapted to colder temperatures in situ accumulated significantly more TFA than controls. For both species, the proportion of polyunsaturated fatty acids (PUFA) decreased, and the percentage of saturated fatty acids (SFA) increased significantly after the heat treatment. These results highlight that populations of both species living at warmest temperatures in situ were more thermo-tolerant and exhibited a greater capacity to cope with heat stress by readjusting their lipid composition faster. Finally, exposure of seagrasses to wanner conditions may induce a decrease in PUFA/SFA ratio which could negatively affect their nutritional value and generate important consequences in the healthy state of next trophic levels.