Data from: Ocean acidification increases the sensitivity of and variability in physiological responses of an intertidal limpet to thermal stress

Understanding physiological responses of organisms to warming and ocean acidification is the first step towards predicting the potential population- and community-level ecological impacts of these stressors. Increasingly, physiological plasticity is being recognized as important for organisms to adapt to the changing microclimates. Here, we evaluate the importance of physiological plasticity for coping with ocean acidification and elevated temperature, and its variability among individuals, of the intertidal limpet Cellana toreuma from the same population in Xiamen. Limpets were collected from shaded mid-intertidal rock surfaces. They were acclimated under combinations of different pCO2 concentrations (400 and 1000 ppm, corresponding to a pH of 8.1 and 7.8) and temperatures (20 and 24 °C) in a short-term period (7 days), with the control conditions (20 °C and 400 ppm) representing the average annual temperature and present-day pCO2 level at the collection site. Heart rates (as a proxy for metabolic performance) and expression of genes encoding inducible and constitutive heat-shock proteins (hsp70 and hsc70) at different heat-shock temperatures (26, 30, 34, and 38 °C) were measured. Hsp70 and Hsc70 play important roles in protecting cells from heat stresses, but have different expression patterns, with Hsp70 significantly increased in expression during stress and Hsc70 constitutively expressed and only mildly induced during stress. Analysis of heart rate showed significantly higher temperature coefficients (Q10 rates) for limpets at 20 °C than at 24 °C and post-acclimation thermal sensitivity of limpets at 400 ppm was lower than at 1000 ppm. Expression of hsp70 linearly increased with the increasing heat-shock temperatures, with the largest slope occurring in limpets acclimated under a future scenario (24 °C and 1000 ppm pCO2). These results suggested that limpets showed increased sensitivity and stress response under future conditions. Furthermore, the increased variation in physiological response under the future scenario indicated that some individuals have higher physiological plasticity to cope with these conditions. While short-term acclimation to reduced pH seawater decreases the ability of partial individuals against thermal stress, physiological plasticity and variability seem to be crucial in allowing some intertidal animals to survive in a rapidly changing environment.解析生物对海洋增温与海洋酸化的生理响应，是预判这两类胁迫因子潜在种群及群落尺度生态影响的首要环节。越来越多研究证实，生理可塑性（physiological plasticity）是生物适应动态变化微气候的关键性状。本研究以采自厦门同一种群的潮间带帽贝（Cellana toreuma）为研究对象，评估其生理可塑性在应对海洋酸化与升温胁迫中的作用，以及个体间的生理可塑性差异。研究所用帽贝采自遮阴的潮间带中部岩面，将其置于不同二氧化碳分压（pCO₂，分别为400、1000 ppm，对应海水pH值8.1与7.8）与温度（20、24℃）的组合条件下进行7天短期驯化，其中对照组条件（20℃、400 ppm）对应采样点的年平均水温与当前大气二氧化碳分压水平。本研究测定了不同热激温度（26、30、34、38℃）下的帽贝心率（作为代谢性能的替代指标），以及编码诱导型与组成型热休克蛋白（heat-shock protein, HSP）的基因hsp70与hsc70的表达水平。Hsp70与Hsc70均在细胞抵御热胁迫过程中发挥重要作用，但二者的表达模式存在显著差异：胁迫条件下Hsp70的表达量显著上调，而Hsc70为组成型表达，仅在胁迫时出现轻度诱导。心率分析结果显示，20℃驯化组帽贝的温度系数（Q₁₀值）显著高于24℃驯化组；且400 ppm（当前环境）驯化组的热敏感性低于1000 ppm（未来酸化）驯化组。hsp70的表达量随热激温度升高呈线性上升，其中以未来情景（24℃、1000 ppm pCO₂）驯化组的表达斜率最大。上述结果表明，未来海洋酸化与升温情景下，帽贝的敏感性与胁迫响应均有所增强。此外，未来情景下帽贝生理响应的离散程度升高，提示部分个体具备更强的生理可塑性以应对该类环境变化。尽管短期暴露于低pH海水会降低部分个体的热胁迫抵御能力，但生理可塑性与个体间的响应差异，仍是部分潮间带动物在快速变化的海洋环境中得以存活的关键因素。