Data from: Symbiont community and host genetic structure of the brain coral Platygyra verweyi, at the outlet of a nuclear power plant and adjacent areas

In the context of rising seawater temperatures associated with climate change, the issue of whether coral holobionts deal with this challenge by shuffling their associations with stress- and/or heat-tolerant Symbiodinium, by generating heat-resistant host genotypes, or both is important for coral survival. In the present study, the composition of communities of the endosymbiont Symbiodinium and the population genetics of the coral host Platygyra verweyi were examined in a reef impacted by hot water discharged from the outlet of a nuclear power plant in operation in Kenting, Southern Taiwan since 1984. The water at this site is 2.0-3.0 ºC warmer than adjacent reefs in summer, which have an average seawater temperature of 29.0 ºC. The data were compared with those for the same species at other sites within 12 km of the outlet site. Platygyra verwyei was associated with one or both of Symbiodinium types C3 (heat sensitive) and D1a (heat tolerant) at all sites with the latter being the dominant at the nuclear power plant outlet. The proportion of C3 in populations increased gradually with increasing distance from the hot-water discharge. Genetic analysis of the Platygyra verweyi host using mitochondrial and nuclear markers showed no genetic differentiation among sites. Changes in the composition of Symbiodinium types associated with P. verweyi among closely located sites in Kenting suggested that this coral might have acclimatized to the constant thermal stress by selective association with heat-tolerant Symbiodinium types, whereas the role of the host in adaptation was inconclusive.

在气候变化导致海水温度持续升高的背景下，珊瑚共生体（coral holobionts）能否通过调整与抗胁迫及/或耐热虫黄藻（Symbiodinium）的共生关系、产生耐热宿主基因型，或同时采用两种策略应对该挑战，对珊瑚的存活至关重要。本研究以中国台湾南部垦丁地区一座自1984年起投产运行的核电站排水口附近受热水排放影响的珊瑚礁为研究对象，分析了其内共生虫黄藻（Symbiodinium）群落组成，以及珊瑚宿主陀螺珊瑚（Platygyra verweyi）的种群遗传学特征。该区域夏季海水温度较周边平均水温29.0℃的相邻珊瑚礁高出2.0-3.0℃。研究将该区域的相关数据与排水口周边12公里范围内其他采样点的同种珊瑚数据进行了对比。所有采样点的陀螺珊瑚（Platygyra verweyi）均与C3型（热敏感型）和/或D1a型（耐热型）虫黄藻共生，其中在核电站排水口区域，D1a型为优势共生类群。C3型虫黄藻在共生群落中的占比随距热水排放口距离的增加逐渐升高。利用线粒体和细胞核分子标记对陀螺珊瑚宿主进行的遗传学分析显示，各采样点间未检测到显著的遗传分化。垦丁地区相邻采样点间陀螺珊瑚所共生的虫黄藻类型组成存在差异，这表明该珊瑚可能通过选择性地与耐热型虫黄藻建立共生关系，以适应持续存在的热胁迫；但宿主自身在珊瑚适应过程中所发挥的作用仍未明确。