The impact of spectral composition and light periodicity on the activity of two antioxidant enzymes (SOD and CAT) in the coral Favia favus

Levy, Oren; Achituv, Y.; Yacobi, Yosef Z.; Stambler, Noga; Dubinsky, Zvy

doi:10.1016/j.jembe.2005.06.018

Cited by 83 publications

(72 citation statements)

References 38 publications

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“…Potential leakage of hydrogen peroxide from Symbiodinium and other dinoflagellates (but also extracellular generation of ROS) has indeed been shown experimentally (Palenik and Morel, 1990;Sandeman, 2006;Suggett et al, 2008;Saragosti et al, 2010). Our findings agree with previous studies that, depending on the coral species, catalase activity per unit protein is usually three to ten times higher (up to twenty-three times in M. digitata) in the host than in the symbiont (Yakovleva et al, 2004;Levy et al, 2006;Higuchi et al, 2008). Although never fully acknowledged before, this observation implies that the host has sufficient scavenging capacity to deal with symbiont-derived hydrogen peroxide.…”

Section: Tablesupporting

confidence: 92%

“…Clearly, cnidarian species differ significantly in their cellular physiology and the strategies employed to mitigate thermally-induced oxidative stress. In contrast, a large body of literature exists that clearly supports the existence and impact of oxidative stress in symbiont and host based on light and UV stress (Dykens and Shick, 1984;Lesser and Shick, 1989a;Lesser and Shick, 1989b;Dykens et al, 1992;Shick et al, 1995;Downs et al, 2002;Lesser and Farrell, 2004;Levy et al, 2006;Kuguru et al, 2010). It is these observations that have mainly shaped the Oxidative Theory of Coral Bleaching, identifying photo-oxidative stress in the symbiont and the leakage of ROS to the host compartment as the initiator of the bleaching cascade.…”

Section: Oxidative Stress As a Light And Temperature Response In Hostmentioning

confidence: 99%

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Differential coral bleaching—Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress

Krueger

Hawkins

Becker

et al. 2015

Comparative Biochemistry and Physiology Part A: Molecular &

115

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Mass coral bleaching due to thermal stress represents a major threat to the integrity and functioning of coral reefs. Thermal thresholds vary, however, between corals, partly as a result of the specific type of endosymbiotic dinoflagellate (Symbiodinium sp.) they harbour. The production of reactive oxygen species (ROS) in corals under thermal and light stress has been recognised as one mechanism that can lead to cellular damage and the loss of their symbiont population (Oxidative Theory of Coral Bleaching). Here, we compared the response of symbiont and host enzymatic antioxidants in the coral species Acropora millepora and Montipora digitata at 28°C and 33°C. A. millepora at 33°C showed a decrease in photochemical efficiency of photosystem II (PSII) and increase in maximum midday excitation pressure on PSII, with subsequent bleaching (declining photosynthetic pigment and symbiont density). M. digitata exhibited no bleaching response and photochemical changes in its symbionts were minor. The symbiont antioxidant enzymes superoxide dismutase, ascorbate peroxidase, and catalase peroxidase showed no significant upregulation to elevated temperatures in either coral, while only catalase was significantly elevated in both coral hosts at 33°C. Increased host catalase activity in the susceptible coral after 5 days at 33°C was independent of antioxidant responses in the symbiont and preceded significant declines in PSII photochemical efficiencies. This finding suggests a potential decoupling of host redox mechanisms from symbiont photophysiology and raises questions about the importance of symbiont-derived ROS in initiating coral bleaching.

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Section: Tablesupporting

confidence: 92%

Section: Oxidative Stress As a Light And Temperature Response In Hostmentioning

confidence: 99%

Differential coral bleaching—Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress

Krueger

Hawkins

Becker

et al. 2015

Comparative Biochemistry and Physiology Part A: Molecular &

115

View full text Add to dashboard Cite

show abstract

“…Here, we have identified several antioxidant genes common to the four coral dinoflagellates (Table 6), including genes from the thioredoxin (Trx) superfamily, as well as superoxide dismutase (SOD Mn) and catalase (CAT) genes. The Trx genes have also been found in two Symbiodinium clades, A and B (Bayer et al, 2012), whereas SOD and CAT genes are known to be involved in the oxidative stress response and scavenging reactive oxygen species (Lesser and Shick, 1989;Lesser, 2006;Levy et al, 2006). Although there are different forms of SOD metalloproteins (McCord and Fridovich, 1969), the conserved SOD Mn form found in mitochondria is also common in bacteria and many eukaryotic algae, and is considered, together with Fe SOD, to be an evolutionarily ancient form of SODs (Lesser, 2006).…”

Section: Discussionmentioning

confidence: 99%

Unfolding the secrets of coral–algal symbiosis

et al. 2014

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Dinoflagellates from the genus Symbiodinium form a mutualistic symbiotic relationship with reefbuilding corals. Here we applied massively parallel Illumina sequencing to assess genetic similarity and diversity among four phylogenetically diverse dinoflagellate clades (A, B, C and D) that are commonly associated with corals. We obtained more than 30 000 predicted genes for each Symbiodinium clade, with a majority of the aligned transcripts corresponding to sequence data sets of symbiotic dinoflagellates and o2% of sequences having bacterial or other foreign origin. We report 1053 genes, orthologous among four Symbiodinium clades, that share a high level of sequence identity to known proteins from the SwissProt (SP) database. Approximately 80% of the transcripts aligning to the 1053 SP genes were unique to Symbiodinium species and did not align to other dinoflagellates and unrelated eukaryotic transcriptomes/genomes. Six pathways were common to all four Symbiodinium clades including the phosphatidylinositol signaling system and inositol phosphate metabolism pathways. The list of Symbiodinium transcripts common to all four clades included conserved genes such as heat shock proteins (Hsp70 and Hsp90), calmodulin, actin and tubulin, several ribosomal, photosynthetic and cytochrome genes and chloroplast-based hemecontaining cytochrome P450, involved in the biosynthesis of xanthophylls. Antioxidant genes, which are important in stress responses, were also preserved, as were a number of calcium-dependent and calcium/calmodulin-dependent protein kinases that may play a role in the establishment of symbiosis. Our findings disclose new knowledge about the genetic uniqueness of symbiotic dinoflagellates and provide a list of homologous genes important for the foundation of coral-algal symbiosis.

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“…As other existing holobiont photoprotective mechanisms, such as MAA accumulation, act outside the yellow-orange range, the CPs in shallow-water corals might provide protection in a vulnerable spectral window, functioning in a similar manner as anthocyanins in higher plants (Merzlyak et al 2008). Finally, important physiological processes in corals, including regulation of genes encoding GFP-like proteins, are controlled by blue light (Levy 2003;Levy et al 2006;Kaniewska et al 2009). Hence, the removal of photons in the longer wavelength range appears to be a sensible strategy to avoid interference between photoprotection and blue-light-regulated processes.…”

Section: Discussionmentioning

confidence: 99%

Screening by coral green fluorescent protein (GFP)-like chromoproteins supports a role in photoprotection of zooxanthellae

et al. 2013

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Green fluorescent protein (GFP)-like pigments are responsible for the vivid colouration of many reefbuilding corals and have been proposed to act as photoprotectants. Their role remains controversial because the functional mechanism has not been elucidated. We provide direct evidence to support a photoprotective role of the non-fluorescent chromoproteins (CPs) that form a biochemically and photophysically distinct group of GFP-like proteins. Based on observations of Acropora nobilis from the Great Barrier Reef, we explored the photoprotective role of CPs by analysing five coral species under controlled conditions. In vitro and in hospite analyses of chlorophyll excitation demonstrate that screening by CPs leads to a reduction in chlorophyll excitation corresponding to the spectral properties of the specific CPs present in the coral tissues. Between 562 and 586 nm, the CPs maximal absorption range, there was an up to 50 % reduction of chlorophyll excitation. The screening was consistent for established and regenerating tissue and amongst symbiont clades A, C and D. Moreover, among two differently pigmented morphs of Acropora valida grown under identical light conditions and hosting subclade type C3 symbionts, high CP expression correlated with reduced photodamage under acute light stress.

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The impact of spectral composition and light periodicity on the activity of two antioxidant enzymes (SOD and CAT) in the coral Favia favus

Cited by 83 publications

References 38 publications

Differential coral bleaching—Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress

Differential coral bleaching—Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress

Unfolding the secrets of coral–algal symbiosis

Screening by coral green fluorescent protein (GFP)-like chromoproteins supports a role in photoprotection of zooxanthellae

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