Sugar enrichment provides evidence for a role of nitrogen fixation in coral bleaching
Sugar enrichment provides evidence for a role of nitrogen fixation in coral bleaching
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DOI：
10.1111/gcb.13695
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发表时间：
2017-09-01
影响因子：
11.6
通讯作者：
Wild, Christian
中科院分区：
文献类型：
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作者：
Pogoreutz, Claudia;Raedecker, Nils;Wild, Christian
由于海面温度上升，珊瑚与藻类共生的破坏（珊瑚白化）已成为全球珊瑚礁面临的前所未有的威胁。尽管经过数十年的研究，我们管理大规模白化事件的能力仍然受到对所涉及过程的不完整的机制理解的阻碍。在这项研究中，我们通过添加糖在没有热和光胁迫的情况下诱导珊瑚白化表型。添加糖导致珊瑚共生分解，同时珊瑚相关微生物固氮量增加4倍。与此同时，珊瑚宿主和藻类共生体的氮磷比增加表明，珊瑚整体生物体内氮的可用性过剩，氮限制被破坏。由于在海洋变暖的情况下，固氮作用也受到类似的刺激，因此我们提出了一个改进的珊瑚白化模型，该模型整合了受刺激的微生物固氮作用的级联效应。该模型强调了固氮微生物在珊瑚全息生物功能和分解中的假定作用。
The disruption of the coral-algae symbiosis (coral bleaching) due to rising sea surface temperatures has become an unprecedented global threat to coral reefs. Despite decades of research, our ability to manage mass bleaching events remains hampered by an incomplete mechanistic understanding of the processes involved. In this study, we induced a coral bleaching phenotype in the absence of heat and light stress by adding sugars. The sugar addition resulted in coral symbiotic breakdown accompanied by a fourfold increase of coral-associated microbial nitrogen fixation. Concomitantly, increased N:P ratios by the coral host and algal symbionts suggest excess availability of nitrogen and a disruption of the nitrogen limitation within the coral holobiont. As nitrogen fixation is similarly stimulated in ocean warming scenarios, here we propose a refined coral bleaching model integrating the cascading effects of stimulated microbial nitrogen fixation. This model highlights the putative role of nitrogen-fixing microbes in coral holobiont functioning and breakdown.