Low levels of ultra-violet radiation mitigate the deleterious effects of nitrate and thermal stress on coral photosynthesis

Blanckaert, Alice C.A.; Marangoni, Laura Fernandes de Barros; Rottier, Cécile; Grover, Renaud; Ferrier‐Pagés, Christine

doi:10.1016/j.marpolbul.2021.112257

Cited by 14 publications

(11 citation statements)

References 87 publications

(115 reference statements)

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“…When coral under thermal stress produces reactive oxygen species (ROS) (Blanckaert A et al 2021), which damage host mitochondria (Nii C M and Muscatine L. 1997). It may be produced by zooxanthellae mainly due to PS II dysfunction caused by damage to the D1 protein (Warner M E. 1999).…”

Section: Discussionmentioning

confidence: 99%

Competitive effects of the macroalgae Caulerpa taxifolia on key physiological processes in the scleratinian coral Turbinaria peltata under thermal stress

Zhou

Yang

et al. 2022

Preprint

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With the degradation of coral reefs induced by climate change and local environmental stressors, an increasing abundance of macroalgae is observed in many reefs. The sublethal damage caused by macroalgae on coral included inhibiting growth, development and reproduction. However, few studies have focused on the dynamics of the interspecific relationship between coral and macroalgae, which may change under climate change. Thus, the effects of thermal stress on the competition between the plate-like coral Turbinaria peltata and macroalgae Caulerpa taxifolia were explored in this study. The responses of corals exposed to the culture water of algae and those in direct contact with algae were also compared. The results showed that at ambient temperature (27 °C), coculture with C. taxifolia reduced the growth rate and protein content of T. peltata by 57.7~65.5% and 37.2~49.0%, respectively, and significantly increased the activities of antioxidant enzymes. Direct contact with C. taxifolia enhanced the activities of antioxidant enzymes further compared to coral exposed to algae. The density and chlorophyll a content of symbiotic zooxanthellae were not obviously influenced based on whether the coral T. peltata was cultured with C. taxifolia. When the temperature was increased by 3 °C, the growth rate of T. peltata decreased to the level of corals exposed to C. taxifolia at ambient temperature, whereas the same pattern was seen in the increase in antioxidant enzyme activity. Additionally, the density and chlorophyll a content of symbiotic zooxanthellae, as well as the feeding rate of coral, showed an evident decrease with increasing temperature. However, thermal stress was only shown in the feeding rate when T. peltata was in indirect contact with C. taxifolia. The interaction of macroalgae contact and thermal stress was evident in the growth rate, protein content, feeding rate and catalase activity (CAT) of coral compared to coral intact with algae under ambient temperature. These results indicated that the negative effects of the macroalgae C. taxifolia on the coral T. peltata are comparable to those of ocean warming, and the competition between corals and macroalgae may be more intense under thermal stress.

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Section: Discussionmentioning

confidence: 99%

Competitive effects of the macroalgae Caulerpa taxifolia on key physiological processes in the scleratinian coral Turbinaria peltata under thermal stress

Zhou

Yang

et al. 2022

Preprint

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“…By contrast, the direct effects of light vary depending on the dosage. Mild to moderate elevations in UV radiation have been observed to enhance photosynthesis, while high levels of UV radiation directly inhibit photosynthesis (Blanckaert et al ., 2021). Therefore, understanding trigger intensity, trigger duration, the presence of multiple triggers, and the taxonomic composition of the coral holobiont are all necessary for deducing how photosynthesis might be affected by a stressor(s).…”

Section: Bleaching Cascadesmentioning

confidence: 99%

“…ONOO − is generated during the bleaching process (Blanckaert et al ., 2021; Fernandes de Barros Marangoni et al ., 2020; Hawkins & Davy, 2013) although whether it is a central mediator of bleaching or simply a cytotoxic byproduct of other mediating cascades remains unresolved. ONOO − was only observed in low abundance during bleaching in E. diaphana and ONOO − scavengers did not reduce bleaching, suggesting that ONOO − is not a mediator of bleaching in this system (Hawkins & Davy, 2013).…”

Section: Bleaching Cascadesmentioning

confidence: 99%

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

Helgoe,

Davy,

Weis

et al. 2024

Biological Reviews

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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).

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“…This imbalance could lead to higher levels of nitrogen fixation by the coral microbiome and other reef-dwelling organisms. On the other hand, exposure to low levels of artificial, full-spectrum UV radiation (equivalent to 15 m depth on tropical coral reefs) was shown to mitigate thermal stress and nitrate-induced inhibition of photosynthesis by promoting the synthesis of antioxidant compounds and MAAs in P. damicornis [ 236 ]. Thus, mild UV irradiation can protect corals against the effects of other types of stress.…”

Section: The Adverse Effects Of Uv Radiation and The Defences Against...mentioning

confidence: 99%

The response of aquatic ecosystems to the interactive effects of stratospheric ozone depletion, UV radiation, and climate change

Neale

Williamson

Banaszak

et al. 2023

Photochem Photobiol Sci

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Variations in stratospheric ozone and changes in the aquatic environment by climate change and human activity are modifying the exposure of aquatic ecosystems to UV radiation. These shifts in exposure have consequences for the distributions of species, biogeochemical cycles, and services provided by aquatic ecosystems. This Quadrennial Assessment presents the latest knowledge on the multi-faceted interactions between the effects of UV irradiation and climate change, and other anthropogenic activities, and how these conditions are changing aquatic ecosystems. Climate change results in variations in the depth of mixing, the thickness of ice cover, the duration of ice-free conditions and inputs of dissolved organic matter, all of which can either increase or decrease exposure to UV radiation. Anthropogenic activities release oil, UV filters in sunscreens, and microplastics into the aquatic environment that are then modified by UV radiation, frequently amplifying adverse effects on aquatic organisms and their environments. The impacts of these changes in combination with factors such as warming and ocean acidification are considered for aquatic micro-organisms, macroalgae, plants, and animals (floating, swimming, and attached). Minimising the disruptive consequences of these effects on critical services provided by the world’s rivers, lakes and oceans (freshwater supply, recreation, transport, and food security) will not only require continued adherence to the Montreal Protocol but also a wider inclusion of solar UV radiation and its effects in studies and/or models of aquatic ecosystems under conditions of the future global climate. Graphical abstract

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Low levels of ultra-violet radiation mitigate the deleterious effects of nitrate and thermal stress on coral photosynthesis

Cited by 14 publications

References 87 publications

Competitive effects of the macroalgae Caulerpa taxifolia on key physiological processes in the scleratinian coral Turbinaria peltata under thermal stress

Competitive effects of the macroalgae Caulerpa taxifolia on key physiological processes in the scleratinian coral Turbinaria peltata under thermal stress

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

The response of aquatic ecosystems to the interactive effects of stratospheric ozone depletion, UV radiation, and climate change

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