Heat-evolved microalgal symbionts increase coral bleaching tolerance
Heat-evolved microalgal symbionts increase coral bleaching tolerance
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DOI：
10.1126/sciadv.aba2498
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发表时间：
2020-05-01
期刊：
影响因子：
13.6
通讯作者：
van Oppen, M. J. H.
中科院分区：
文献类型：
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作者：
Buerger, P.;Alvarez-Roa, C.;van Oppen, M. J. H.
世界各地的珊瑚礁正在遭受海洋热浪的大规模死亡。为了提高珊瑚对白化的耐受性，我们在实验室中在高温（31摄氏度）下进化了10个普通珊瑚微藻内共生克隆菌株。所有10个热进化菌株在实验室进化后，其体外耐热性都得到了提高。在重新引入珊瑚寄主幼虫后，10种热进化的内共生体中有3种也增加了全息共生体的漂白耐受性。虽然较低水平的活性氧（ROS）分泌伴随着热进化藻类的耐热性，但仅减少ROS分泌并不能预测共生中的耐热性。在较强的共生关系中，藻类固碳基因和珊瑚耐热基因的组成表达量也较高。这些发现表明，具有增强气候适应能力的珊瑚种群可以通过其微藻内共生生物的非医院实验室进化而发展。
Coral reefs worldwide are suffering mass mortalities from marine heat waves. With the aim of enhancing coral bleaching tolerance, we evolved 10 clonal strains of a common coral microalgal endosymbiont at elevated temperatures (31 degrees C) for 4 years in the laboratory. All 10 heat-evolved strains had expanded their thermal tolerance in vitro following laboratory evolution. After reintroduction into coral host larvae, 3 of the 10 heat-evolved endo-symbionts also increased the holobionts' bleaching tolerance. Although lower levels of secreted reactive oxygen species (ROS) accompanied thermal tolerance of the heat-evolved algae, reduced ROS secretion alone did not predict thermal tolerance in symbiosis. The more tolerant symbiosis exhibited additional higher constitutive expression of algal carbon fixation genes and coral heat tolerance genes. These findings demonstrate that coral stock with enhanced climate resilience can be developed through ex hospite laboratory evolution of their microalgal endosymbionts.