Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, 48824, MI, USA.
Plant, Soil and Microbial Science Department, Michigan State University, East Lansing, 48824, MI, USA.
Sci Total Environ. 2024 Jan 1;906:167803. doi: 10.1016/j.scitotenv.2023.167803. Epub 2023 Oct 13.
Scleractinian assemblages are threatened by marine heat waves with coral survivorship depending on host genetics and microbiome composition. We documented an extreme marine heat wave in Fiji and the response of corals in two thermally stressed reef flats. Through high-throughput amplicon sequencing of 16S and ITS rDNA phylogenetic markers, we assessed coral microbiomes (Symbiodiniaceae, prokaryotes, fungi, and Apicomplexa) of paired bleached and unbleached colonies of four common coral species representative of dominant genera in the South Pacific. While all coral species exhibited one or more pathways to bleaching resistance, harboring assemblages composed primarily of thermally tolerant photosymbionts did not always result in host bleaching resistance. Montipora and Pocillopora species, which associate with diverse Symbiodiniaceae and vertically transmit their photosymbionts, fared better than Acropora, which acquire their photosymbionts from the environment, and Porites, which associate with a narrow photosymbiont assemblage. Prokaryotic and fungal beta diversity did not differ between bleached and unbleached conspecifics, however, the relative abundance of the fungus Malassezia globosa was significantly greater in unbleached colonies of Montipora digitata. Each coral species harbored distinct assemblages of Symbiodiniaceae, prokaryotes, and Apicomplexa, but not fungi, reiterating the importance of host genetics in structuring components of its microbiome. Terrestrial fungal and prokaryotic taxa were detected at low abundance across coral microbiomes, indicating that allochthonous microbial inputs occur, but that coral microbiomes remain dominated by marine microbial taxa. Our study offers valuable insights into the microbiome assemblages associated with coral tolerance to extreme water temperatures.
造礁石珊瑚组合受到海洋热浪的威胁，珊瑚的存活率取决于宿主的遗传和微生物组组成。我们记录了斐济的一次极端海洋热浪和两个受热胁迫的珊瑚礁平原中珊瑚的反应。通过高通量扩增子测序 16S 和 ITS rDNA 系统发育标记物，我们评估了四个常见珊瑚物种的共生微生物组（共生藻、原核生物、真菌和顶复门原生动物），这些珊瑚物种代表了南太平洋优势属的代表。虽然所有珊瑚物种都表现出一种或多种抗白化途径，但主要由耐热共生藻组成的共生体并不总是导致宿主抗白化。与多种共生藻相关并垂直传播其共生藻的 Montipora 和 Pocillopora 物种比从环境中获取共生藻的 Acropora 和与狭窄共生藻组合相关的 Porites 物种表现得更好。在白化和未白化的同种珊瑚中，原核生物和真菌的β多样性没有差异，然而，Montipora digitata 未白化珊瑚中的真菌 Malassezia globosa 的相对丰度显著更高。每个珊瑚物种都具有独特的共生藻、原核生物和顶复门原生动物组合，但不包括真菌，这再次强调了宿主遗传在构建其微生物组组成部分中的重要性。陆地真菌和原核生物类群在珊瑚微生物组中的丰度较低，表明存在异源微生物输入，但珊瑚微生物组仍然以海洋微生物类群为主。我们的研究为与珊瑚对极端水温的耐受性相关的微生物组组合提供了有价值的见解。
