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

Autor: Helgoe J; Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA., Davy SK; School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand., Weis VM; Department of Integrative Biology, Oregon State University, 2701 SW Campus Way, 2403 Cordley Hall, Corvallis, OR, USA., Rodriguez-Lanetty M; Department of Biological Sciences, Institute of Environment, Florida International University, 11200 SW 8th Street, OE 167, Miami, FL, USA.; Department of Biological Sciences, Biomolecular Sciences Institute, Florida International University, 11200 SW 8th Street, Miami, FL, USA.
Jazyk: angličtina
Zdroj: Biological reviews of the Cambridge Philosophical Society [Biol Rev Camb Philos Soc] 2024 Jun; Vol. 99 (3), pp. 715-752. Date of Electronic Publication: 2024 Jan 12.
DOI: 10.1111/brv.13042
Abstrakt: The intracellular coral-dinoflagellate symbiosis is the engine that underpins the success of coral reefs, one of the most diverse ecosystems on the planet. However, the breakdown of the symbiosis and the loss of the microalgal symbiont (i.e. coral bleaching) due to environmental changes are resulting in the rapid degradation of coral reefs globally. There is an urgent need to understand the cellular physiology of coral bleaching at the mechanistic level to help develop solutions to mitigate the coral reef crisis. Here, at an unprecedented scope, we present novel models that integrate putative mechanisms of coral bleaching within a common framework according to the triggers (initiators of bleaching, e.g. heat, cold, light stress, hypoxia, hyposalinity), cascades (cellular pathways, e.g. photoinhibition, unfolded protein response, nitric oxide), and endpoints (mechanisms of symbiont loss, e.g. apoptosis, necrosis, exocytosis/vomocytosis). The models are supported by direct evidence from cnidarian systems, and indirectly through comparative evolutionary analyses from non-cnidarian systems. With this approach, new putative mechanisms have been established within and between cascades initiated by different bleaching triggers. In particular, the models provide new insights into the poorly understood connections between bleaching cascades and endpoints and highlight the role of a new mechanism of symbiont loss, i.e. 'symbiolysosomal digestion', which is different from symbiophagy. This review also increases the approachability of bleaching physiology for specialists and non-specialists by mapping the vast landscape of bleaching mechanisms in an atlas of comprehensible and detailed mechanistic models. We then discuss major knowledge gaps and how future research may improve the understanding of the connections between the diverse cascade of cellular pathways and the mechanisms of symbiont loss (endpoints).
(© 2024 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.)
Databáze: MEDLINE
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