珊瑚脂类生物标志物组成及对环境的响应 ：研究进展与问题

Response of coral lipid biomarkers to the environment: progress and problems

关键词:  珊瑚骨骼  环境胁迫  脂肪酸  甾醇  古环境

Key words:  coral skeleton  environmental stresses  fatty acid  sterol  paleoenvironment

摘要:

脂类是现代活珊瑚组织中细胞膜的结构成分以及重要的信号分子，在能量储存以及适应极端环境等方面发挥重要作用。珊瑚对海洋环境变化响应异常灵敏，能够通过改变自身脂类的组成和结构适应环境变化并产生特征性的脂类分子记录，对现代珊瑚以及化石珊瑚中脂类化合物进行研究，有助于深刻认识全球变化时期环境与生命协同演化过程。在国内外珊瑚脂类生物标志物的研究基础上，综述珊瑚及其文石骨骼中脂类化合物的分布特征，以及脂类对环境变化（如温度、光照、CO₂）响应的研究进展。珊瑚中的脂类化合物能够灵敏地响应环境变化，已有研究表明温度能明显地影响珊瑚组织中脂肪酸与甾醇的含量及分布。其中，珊瑚中的甾醇类受光照、温度以及营养方式等环境因素影响，并且种属间也表现出明显差异。研究表明珊瑚骨骼间微环境的物理化学特性是影响骨骼中脂类分布的重要因素。因此环境变化对珊瑚软组织以及骨骼中脂类的含量与分布具有显著影响，然而在现代过程中海洋环境对珊瑚组织中脂类分布的影响及定量关系还需进一步研究，其对环境响应的规律总结是研究珊瑚礁应对极端环境的基础。通过综述国内外珊瑚脂类的相关研究，为探究珊瑚脂类生物标志物记录生物地球协同演化过程提供更多见解。

Abstract:

Background, aim, and scope Lipids are the structural components of cell membranes and important signaling molecules in modern coral tissues that play an important role in energy storage and adaptation to extreme environments. Corals are highly responsive to changes in the marine environment; they can adapt to environmental changes and produce characteristic biogeochemical records by altering their lipid composition and structure. The study of lipid compounds in modern and fossil corals will help us understand the co-evolutionary process of the environment and life during the period of global change. Materials and methods Based on the research of coral lipid biomarkers at home and abroad, this paper reviews the distribution characteristics of coral and aragonite lipid compounds and the response of coral lipid compounds to environmental changes (temperature, light, and CO₂). Results Lipid compounds in corals respond sensitively to environmental changes. Temperature can significantly affect the content and distribution of fatty acids and sterols in coral tissues. Sterols in corals are influenced by environmental factors such as light, temperature, and nutritional modes, and show obvious differences among species. In addition, the physicochemical properties of the microenvironment between coral skeletons are important factors that affect the distribution of lipids in the skeletons. Discussion In the modern process, the influence of the marine environment on the distribution of lipids in coral tissues and their quantitative relationship needs to be further studied, and a rule summary of their response to the environment is the basis for studying the response of coral reefs to extreme environments. Previous studies have shown that temperature significantly affects the content and distribution of fatty acids and sterols in coral tissues. In addition, sterols in corals are affected by light, temperature, and nutritional mode, and their compositional characteristics differ among species. Moreover, the physical and chemical characteristics of the microenvironment between coral bones affect the distribution of lipids in the bones and play an important role in calcification. Therefore, environmental changes significantly affect the lipid content and distribution in coral tissues and bones. Conclusions Coral extracts are rich in lipid compounds and respond sensitively to environmental changes. In addition, coral lipids differ depending on the species and region. Recommendations and perspectives Currently, research on coral lipid compounds mainly focuses on analyzing the lipid content and composition of modern corals, as well as the response of coral lipids to environmental conditions. Therefore, it is necessary to conduct systematic research on the modern process of coral reef lipids in the future. For example, in addition to considering the impact of individual environmental factors on coral lipids, the synergistic response process between their lipid compounds and multiple environmental factors should also be explored. It is also necessary to further explore the influence of early diagenesis of reef-building corals on the distribution and content of lipid compounds in coral skeletons. This will help to better apply biomarker compounds in modern coral reefs to geological historical periods and provide relevant evidence for modern processes reflected in the paleoclimate and paleoenvironment of coral reef lipids in geological carriers.