Data from: Dimethylsulphoniopropionate, superoxide dismutase and glutathione as stress response indicators in three corals under short-term hyposalinity stress

Corals are amongst the most active producers of dimethylsulphoniopropionate (DMSP), a key molecule in marine sulphur cycling, yet the specific physiological role of DMSP in corals remains elusive. Here we examine the oxidative stress response of three coral species (Acropora millepora, Stylophora pistillata and Pocillopora damicornis) and explore the antioxidant role of DMSP and its breakdown products under short-term hyposalinity stress. Symbiont photosynthetic activity declined with hyposalinity exposure in all three reef-building corals. This corresponded with the up-regulation of superoxide dismutase (SOD) and glutathione (GSx) in the animal host of all three species. For the symbiont component, there were differences in antioxidant regulation, demonstrating differential responses to oxidative stress between the Symbiodinium sub-clades. Of the three coral species investigated, only A. millepora provided any evidence of the role of DMSP in the oxidative stress response. Our study reveals variability in antioxidant regulation in corals and highlights the influence life history traits and the subcladal differences can have on coral physiology. Our data expands on the emerging understanding of the role of DMSP in coral stress regulation and emphasises the importance of exploring both the host and symbiont responses for defining the threshold of the coral holobiont to hyposalinity stress.

珊瑚是二甲基巯基丙酸内盐（dimethylsulphoniopropionate, DMSP）的主要活性生产者之一，该物质是海洋硫循环中的关键分子，但DMSP在珊瑚体内的具体生理功能仍未明确。本研究针对三种造礁珊瑚——米氏鹿角珊瑚（Acropora millepora）、指状轴孔珊瑚（Stylophora pistillata）和鹿角杯形珊瑚（Pocillopora damicornis）——的氧化应激响应展开研究，并探讨了DMSP及其降解产物在短期低盐胁迫下的抗氧化功能。三种造礁珊瑚的共生藻光合活性均随低盐胁迫暴露程度加深而降低，该现象与三种珊瑚宿主体内超氧化物歧化酶（SOD）和谷胱甘肽（GSx）的表达上调相一致。而就共生藻组分而言，其抗氧化调控模式存在差异，表明虫黄藻（Symbiodinium）亚分支间对氧化应激的响应各不相同。在所研究的三种珊瑚中，仅米氏鹿角珊瑚（A. millepora）表现出DMSP参与氧化应激响应的相关证据。本研究揭示了珊瑚抗氧化调控的多样性，并强调了生活史特征与亚分支差异对珊瑚生理的影响。本研究数据拓展了学界对DMSP在珊瑚胁迫调控中作用的新兴认知，并强调了同时探究宿主与共生藻响应，对于明确珊瑚共生联合体（holobiont）应对低盐胁迫的阈值具有重要意义。