Triggers, cascades, and endpoints: connecting the dots of coral bleaching mechanisms

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2024, Volume and Issue: 99(3), P. 715 - 752

Published: Jan. 12, 2024

ABSTRACT The intracellular coral–dinoflagellate symbiosis is the engine that underpins success of coral reefs, one most diverse ecosystems on planet. However, breakdown and loss microalgal symbiont (i.e. bleaching) due to environmental changes are resulting in rapid degradation reefs globally. There an urgent need understand cellular physiology bleaching at mechanistic level help develop solutions mitigate reef crisis. Here, unprecedented scope, we present novel models integrate putative mechanisms within a common framework according triggers (initiators bleaching, e.g. heat, cold, light stress, hypoxia, hyposalinity), cascades (cellular pathways, photoinhibition, unfolded protein response, nitric oxide), endpoints (mechanisms loss, apoptosis, necrosis, exocytosis/vomocytosis). supported by direct evidence from cnidarian systems, indirectly through comparative evolutionary analyses non‐cnidarian systems. With this approach, new have been established between initiated different triggers. In particular, provide insights into poorly understood connections highlight role mechanism i.e. ‘symbiolysosomal digestion’, which symbiophagy. This review also increases approachability for specialists non‐specialists mapping vast landscape atlas comprehensible detailed models. We then discuss major knowledge gaps how future research may improve understanding cascade pathways (endpoints).

Language: Английский

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Defining Coral Bleaching as a Microbial Dysbiosis within the Coral Holobiont

Microorganisms, Journal Year: 2020, Volume and Issue: 8(11), P. 1682 - 1682

Published: Oct. 29, 2020

Coral microbiomes are critical to holobiont health and functioning, but the stability of host–microbial interactions is fragile, easily shifting from eubiosis dysbiosis. The heat-induced breakdown symbiosis between host its dinoflagellate algae (that is, “bleaching”), one most devastating outcomes for reef ecosystems. Yet, bleaching tolerance has been observed in some coral species. This review provides an overview holobiont’s diversity, explores thermal relation their associated microorganisms, discusses hypothesis adaptive dysbiosis as a mechanism environmental adaptation, mentions potential solutions mitigate bleaching, suggests new research avenues. More specifically, we define succession three stages, where microbiota can (i) maintain essential functions homeostasis during stress and/or (ii) act buffer by favoring recruitment thermally tolerant Symbiodiniaceae species (adaptive dysbiosis), (iii) stressors exceed buffering capacity both microbial partners leading death.

Language: Английский

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Coral environmental memory: causes, mechanisms, and consequences for future reefs

Trends in Ecology & Evolution, Journal Year: 2021, Volume and Issue: 36(11), P. 1011 - 1023

Published: Aug. 5, 2021

Language: Английский

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Avenues of reef-building coral acclimatization in response to rapid environmental change

Journal of Experimental Biology, Journal Year: 2021, Volume and Issue: 224(Suppl_1)

Published: Feb. 15, 2021

ABSTRACT The swiftly changing climate presents a challenge to organismal fitness by creating mismatch between the current environment and phenotypes adapted historic conditions. Acclimatory mechanisms may be especially crucial for sessile benthic marine taxa, such as reef-building corals, where change factors including ocean acidification increasing temperature elicit strong negative physiological responses bleaching, disease mortality. Here, within context of multiple stressors threatening organisms, I describe wealth metaorganism response rapid ontogenetic shifts in organism interactions with that can generate plasticity. then highlight need consider evolutionary an adaptive (epi)genetic continuum. Building on definitions these continuum, also present how interplay microbiome, epigenetics parental effects creates additional avenues acclimatization. To under what conditions epigenetic inheritance has more substantial role, propose investigation into offset timing gametogenesis leading different environmental integration times eggs sperm consequences this gamete compatibility. Collectively, non-genetic, yet heritable phenotypic plasticity will have significant ecological implications persistence change. As such, corals ideal time-sensitive models further development our understanding feedback loops multi-player

Language: Английский

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Meta‐analysis of the coral environmental stress response: Acropora corals show opposing responses depending on stress intensity

Molecular Ecology, Journal Year: 2020, Volume and Issue: 29(15), P. 2855 - 2870

Published: July 2, 2020

Abstract As climate change progresses, reef‐building corals must contend more often with suboptimal conditions, motivating a need to understand coral stress response. Here, we test the hypothesis that there is stereotyped transcriptional response enact under all stressful functionally characterized by downregulation of growth, and activation cell death, reactive oxygen species, immunity, protein folding degradation. We analyse RNA‐seq Tag‐Seq data from 14 previously published studies supplement them four new experiments involving different stressors, totaling over 600 gene expression profiles genus Acropora . Contrary expectations, found not one, but two distinct types The type A was observed kinds high‐intensity stress, correlated between independent projects consistent hypothesized correlation projects, irrespective type, supports as general environmental (ESR), blanket solution severely conditions. B lower intensity variable among studies. Unexpectedly, at level individual genes functional categories, broadly opposite Finally, taking advantage breadth set, present contextual annotations for unannotated based on stress‐induced differences across projects.

Language: Английский

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Coral bleaching response is unaltered following acclimatization to reefs with distinct environmental conditions

Proceedings of the National Academy of Sciences, Journal Year: 2021, Volume and Issue: 118(22)

Published: May 28, 2021

Urgent action is needed to prevent the demise of coral reefs as climate crisis leads an increasingly warmer and more acidic ocean. Propagating change-resistant corals restore degraded one promising strategy; however, empirical evidence determine whether stress resistance affected by transplantation beyond a coral's native reef. Here, we assessed performance bleaching-resistant individuals two species following reciprocal between with distinct pH, salinity, dissolved oxygen, sedimentation, flow dynamics heat response altered exposure novel physicochemical conditions in situ. Critically, had no influence on responses, indicating that this trait was relatively fixed. In contrast, growth highly plastic, not predictive environment. Coral metabolic rates overall fitness were higher at reef flow, diel fluctuations pH did differ cross-transplanted corals, acclimatization via plasticity within just 3 mo. Conversely, cross-transplants second than thus increasing potential recipient population. This experiment conducted during nonbleaching year, so benefits population are likely enhanced bleaching years. summary, study demonstrates outplanting tool for elevating populations ocean warming.

Language: Английский

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Expression plasticity regulates intraspecific variation in the acclimatization potential of a reef-building coral

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Aug. 15, 2022

Phenotypic plasticity is an important ecological and evolutionary response for organisms experiencing environmental change, but the ubiquity of this capacity within coral species across symbiont communities unknown. We exposed ten genotypes reef-building Montipora capitata with divergent to four thermal pre-exposure profiles quantified gene expression before stress testing 4 months later. Here we show two significantly enhance tolerance despite broadly different patterns substantial variation in acclimatization potential based on genotype. There was no relationship between a genotype's basal sensitivity ability acquire heat tolerance, including corals harboring naturally tolerant symbionts, which illustrates additive improvements climate change. These results represent durable from short-term hardening cryptic complexity plasticity.

Language: Английский

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The impact of rising temperatures on the prevalence of coral diseases and its predictability: A global meta‐analysis

Ecology Letters, Journal Year: 2023, Volume and Issue: 26(8), P. 1466 - 1481

Published: June 6, 2023

Abstract Coral reefs are under threat from disease as climate change alters environmental conditions. Rising temperatures exacerbate coral disease, but this relationship is likely complex other factors also influence prevalence. To better understand relationship, we meta‐analytically examined 108 studies for changes in global over time alongside temperature, expressed using average summer sea surface temperature (SST) and cumulative heat stress weekly anomalies (WSSTAs). We found that both rising SST WSSTA were associated with increases the mean variability Global prevalence tripled, reaching 9.92% 25 years examined, effect of ‘year’ became more stable (i.e. has lower variance time), contrasting effects two stressors. Regional patterns diverged differed response to SST. Our model predicted that, same trajectory, 76.8% corals would be diseased globally by 2100, even assuming moderate WSSTA. These results highlight need urgent action mitigate disease. Mitigating impact ocean on a challenge requiring discussion further study.

Language: Английский

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Assessing acute thermal assays as a rapid screening tool for coral restoration

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: Jan. 22, 2024

Abstract Escalating environmental threats to coral reefs coincides with global advancements in restoration programs. To improve long-term efficacy, practitioners must consider incorporating genotypes resilient ocean warming and disease while maintaining genetic diversity. Identifying such typically occurs under exposures that mimic natural stressors, but these experiments can be time-consuming, costly, introduce tank effects, hindering scalability for hundreds of nursery used outplanting. Here, we evaluated the efficacy acute Coral Bleaching Automated Stress System (CBASS) against on bleaching response Acropora cervicornis , dominant species Florida’s Reef. Comparing metrics, F v / m chlorophyll, host protein, observed similar responses between heat CBASS treatment 34.3 °C, which was also calculated threshold. This suggests potential as a rapid screening tool, 90% exhibiting tolerances. However, variations phenotypes arose from measurement timing experiment accumulation, cautioning generalizations solely based metrics like . These findings identify need better refine tools necessary quickly effectively screen determine their relative tolerance interventions.

Language: Английский

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Microplastics in the coral ecosystems: A threat which needs more global attention

Ocean & Coastal Management, Journal Year: 2024, Volume and Issue: 249, P. 107012 - 107012

Published: Jan. 17, 2024

Language: Английский

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