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Summary Sphagnumpeatmosses are fundamental members of peatland ecosystems, where they contribute to the uptake and long‐term storage of atmospheric carbon. Warming threatensSphagnummosses and is known to alter the composition of their associated microbiome. Here, we use a microbiome transfer approach to test if microbiome thermal origin influences host plant thermotolerance.We leveraged an experimental whole‐ecosystem warming study to collect field‐grownSphagnum, mechanically separate the associated microbiome and then transfer onto germ‐free laboratorySphagnumfor temperature experiments. Host and microbiome dynamics were assessed with growth analysis, Chlafluorescence imaging, metagenomics, metatranscriptomics and 16S rDNA profiling.Microbiomes originating from warming field conditions imparted enhanced thermotolerance and growth recovery at elevated temperatures. Metagenome and metatranscriptome analyses revealed that warming altered microbial community structure in a manner that induced the plant heat shock response, especially the HSP70 family and jasmonic acid production. The heat shock response was induced even without warming treatment in the laboratory, suggesting that the warm‐microbiome isolated from the field provided the host plant with thermal preconditioning.Our results demonstrate that microbes, which respond rapidly to temperature alterations, can play key roles in host plant growth response to rapidly changing environments.
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Host–microbial systems as glass cannons: Explaining microbiome stability in corals exposed to extrinsic perturbations
Abstract Although stability is relatively well understood in macro‐organisms, much less is known about its drivers in host–microbial systems where processes operating at multiple levels of biological organisation jointly regulate the microbiome.We conducted an experiment to examine the microbiome stability of three Caribbean corals (Acropora cervicornis,Pseudodiploria strigosaandPorites astreoides) by placing them in aquaria and exposing them to a pulse perturbation consisting of a large dose of broad‐spectrum antibiotics before transplanting them into the field.We found that coral hosts harboured persistent, species‐specific microbiomes. Stability was generally high but variable across coral species, withA. cervicornismicrobiomes displaying the lowest community turnover in both the non‐perturbed and the perturbed field transplants. Interestingly, the microbiome ofP. astreoideswas stable in the non‐perturbed field transplants, but unstable in the perturbed field transplants.A mathematical model of host–microbial dynamics helped resolve this paradox by showing that when microbiome regulation is driven by host sanctioning, both resistance and resilience to invasion are low and can lead to instability despite the high direct costs bourne by corals. Conversely, when microbiome regulation is mainly associated with microbial processes, both resistance and resilience to invasion are high and promote stability at no direct cost to corals. We suggest that corals that are mainly regulated by microbial processes can be likened to ‘glass cannons’ because the high stability they exhibit in the field is due to their microbiome's potent suppression of invasive microbes. However, these corals are susceptible to destabilisation when exposed to perturbations that target the vulnerable members of their microbiomes who are responsible for mounting such powerful attacks against invasive microbes. The differential patterns of stability exhibited byP. astreoidesacross perturbed and non‐perturbed field transplants suggest it is a ‘glass cannon’ whose microbiome is regulated by microbial processes, whereasA. cervicornis’ consistent patterns of stability suggest that its microbiome is mainly regulated by host‐level processes.Our results show that understanding how processes that operate at multiple levels of biological organisation interact to regulate microbiomes is critical for predicting the effects of environmental perturbations on host–microbial systems.
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- Award ID(s):
- 1924145
- PAR ID:
- 10386483
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Journal of Animal Ecology
- Volume:
- 90
- Issue:
- 5
- ISSN:
- 0021-8790
- Page Range / eLocation ID:
- p. 1044-1057
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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