The interaction between the proliferating macroalga Asparagopsis taxiformis and the coral Astroides calycularis induces changes in microbiome and metabolomic fingerprints

Abstract

Mediterranean Sea ecosystems are considered as hotspots of biological introductions, exposed to possible negative effects of non–indigenous species. In such temperate marine ecosystems, macroalgae may be dominant, with a great percentage of their diversity represented by introduced species. Their interaction with temperate indigenous benthic organisms have been poorly investigated. To provide new insights, we performed an experimental study on the interaction between the introduced proliferative red alga Asparagopsis taxiformis and the indigenous Mediterranean coral Astroides calycularis. The biological response measurements included meta–barcoding of the associated microbial communities and metabolomic fingerprinting of both species. Significant changes were detected among both associated microbial communities, the interspecific differences decreasing with stronger host interaction. No short term effects of the macroalga on the coral health, neither on its polyp activity or its metabolism, were detected. In contrast, the contact interaction with the coral induced a change in the macroalgal metabolomic fingerprint with a significant increase of its bioactivity against the marine bacteria Aliivibrio fischeri. This induction was related to the expression of bioactive metabolites located on the macroalgal surface, a phenomenon which might represent an immediate defensive response of the macroalga or an allelopathic offense against coral.

Impact of ocean acidification on the metabolome of the brown macroalgae Lobophora rosacea from New Caledonia

“…For marine organisms, and especially non-model organisms, metabolite annotation is often limited by a lack of standards (e.g. Gaubert et al, 2019b, 2019a, Greff et al, 2017b, 2017aSogin et al, 2016). This issue is one of the greatest challenges in untargeted metabolomic studies (Kumar et al, 2016).…”

“…Further investigation is needed, including coral-algal interaction experiments (e.g. Del Monaco et al, 2017;Greff et al, 2017a), to evaluate the potential impact of L. rosacea on corals in the context of ocean acidification.…”

“…Environmental metabolomics is a growing technique used in marine science (Gaubert et al, 2019b;Greff et al, 2017a;Jaramillo et al, 2018;Viant, 2007) as it has a huge potential for exploring the responses of organisms to environmental conditions and for deciphering the metabolic pathways involved. Multi-stressor environments (e.g.…”

High metabolic variation for seaweeds in response to environmental changes: a case study of the brown algae Lobophora in coral reefs

“…However these interactions are still scarcely investigated at the global metabolomic level. Changes in Asparagopsis taxiformis metabolomic fingerprint were observed after contact with the coral Astroides calycularis 22 and different coral-algal assemblages can alter the coral metabolome 23 . These above-mentioned studies indicate that the metabolome of macroalgae is influenced by abiotic and biotic factors, supporting its involvement in biological processes and adaptation to the environment.…”

Metabarcoding reveals distinct microbiotypes in the giant clam Tridacna maxima

“…The Symbiodiniaceae composition of the reef benthos has been found to influence the Symbiodiniaceae composition of some symbiotic metazoans, e.g., nudibranchs [53]. Furthermore, the associated bacteria and Archaea of coral species have also been shown to vary according to the presence of certain marine organisms (e.g., macroalgae [54]) or their absence (e.g., decrease of coral cover and overfishing [55]). Thus, the environmental microbiome (dinoflagellate algae as well as prokaryotes) that is available for uptake might also greatly depend on the surrounding existing benthic communities.…”