Lipidome analysis of Symbiodiniaceae reveals possible mechanisms of heat stress tolerance in reef coral symbionts
Lipidome analysis of Symbiodiniaceae reveals possible mechanisms of heat stress tolerance in reef coral symbionts
复制标题
共生体的脂质组分析揭示了珊瑚礁珊瑚共生体耐热应激的可能机制
DOI：
10.1007/s00338-019-01865-x
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发表时间：
2019
期刊：
影响因子：
3.5
通讯作者：
Cecilia D'Angelo
中科院分区：
文献类型：
--
作者：
Sabrina L. Rosset;G. Koster;J. Brandsma;A. N. Hunt;A. Postle;Cecilia D'Angelo
气候变化引起的全球变暖威胁着包括浅水珊瑚礁在内的关键生态系统的生存。升高的温度可以通过改变叶绿体膜的流动性和渗透性来破坏光合生物的正常生理功能，叶绿体膜的流动性和渗透性由其脂质组成来定义和调节。由于栖息地形成的珊瑚礁依赖于强制性的共生与甲藻的共生藻科，他们的热应激反应可以预期的强烈影响共生体的脂质代谢。然而，相对于珊瑚共生体在基因组和转录组水平上的功能知识的稳步增加，对它们的膜脂组成和对温度应激的调节的理解是滞后的。我们已经利用基于质谱的lipidomic分析，以确定关键的极性脂质，形成生物膜的珊瑚礁共生体，比较耐热物种Durusdinium trenchii与热敏类群Cladocopia C3，都由鹿角珊瑚。结果表明，具有上级耐热性的D.通过（1）磺基喹诺糖基二酰基甘油的量和饱和度，特别是通过假定的光系统II相互作用，（2）增加的双半乳糖基二酰基甘油与单半乳糖基二酰基甘油的比例，具有稳定类囊体膜和整合蛋白的潜力，以及（3）溶血脂质的伴侣样功能，可以实现宿主珊瑚内的trenchii。因此，我们的研究为珊瑚共生体的耐热性提供了新的见解，有助于了解珊瑚礁生态系统响应和适应由于气候变化而变得越来越频繁的热应激事件的潜力。最后，我们的鉴定共生藻科的耐热性的多种机制，进一步了解光合生物的一般胁迫生理。
Climate change-induced global warming threatens the survival of key ecosystems including shallow water coral reefs. Elevated temperatures can disrupt the normal physiological functioning of photosynthetic organisms by altering the fluidity and permeability of chloroplast membranes that is defined and regulated by their lipid composition. Since the habitat-forming reef corals rely on the obligatory symbiosis with dinoflagellates of the family Symbiodiniaceae, their heat stress response can be expected to be strongly influenced by the symbiont's lipid metabolism. However, in contrast to the steady increase in the knowledge of the functioning of coral symbionts at the genomic and transcriptomic level, the understanding of their membrane lipid composition and regulation in response to temperature stress is lagging behind. We have utilised mass spectrometry-based lipidomic analyses to identify the key polar lipids that form the biological membranes of reef coral symbionts, comparing the thermotolerant species Durusdinium trenchii with the thermosensitive taxon Cladocopium C3, both hosted by Acropora valida. Our results indicate that the superior thermotolerance D. trenchii inside the host corals could be achieved through (1) the amount and saturation of sulfoquinovosyldiacylglycerols, in particular through putative photosystem II interactions, (2) the increased digalactosyldiacylglycerol to monogalactosyldiacylglycerol ratio with the potential to stabilise thylakoid membranes and integrated proteins, and (3) the chaperone-like function of lyso-lipids. Thereby, our study provides novel insights into the heat tolerance of coral symbionts, contributing to the understanding of the potential of coral reef ecosystems to respond and adjust to heat stress events that are becoming more frequent due to climate change. Finally, our identification of multiple mechanisms of heat tolerance in Symbiodiniaceae furthers the knowledge of the general stress physiology of photosynthetic organisms.