PSII photoinhibition and photorepair in Symbiodinium (Pyrrhophyta) differs between thermally tolerant and sensitive phylotypes

Ragni, Maria; Airs, Ruth L.; Hennige, Sebastian; Suggett, David J.; Warner, Mark E.; Geider, Richard J.

doi:10.3354/meps08571

Cited by 106 publications

(113 citation statements)

References 42 publications

Supporting

Mentioning

107

Contrasting

Order By: Relevance

“…Several hypotheses have been proposed to explain how elevated temperatures affect the photochemical pathway: excessive photon absorption by light harvesting antennae damages the PSII reaction center, particularly the D1 protein [17][18][19]; elevated temperatures may limit photosynthesis by destabilizing the thylakoid membranes [7]; the activity of Rubisco may be a primary site of damage by elevated temperature [20], though a recent study suggests that inhibition of the Calvin-Benson cycle alone does not induce coral bleaching [21]; damaged PSII reaction centers may be replaced by re-synthesized D1 protein, but this mechanism is inhibited when temperature is elevated [10]; elevated temperatures may also suppress the synthesis of light harvesting antennae protein at the translational step, thereby promoting losses of major light harvesting proteins [9]. Several of these postulates have been supported by recent studies indicating that the thermal stress susceptibility of Symbiodinium is determined by the repair capacity of the photosynthetic mechanism [10,22,23].…”

Section: Introductionmentioning

confidence: 48%

Temperature Effects on the Growth Rates and Photosynthetic Activities of Symbiodinium Cells

Karim

Nakaema

Hidaka

2015

JMSE

View full text Add to dashboard Cite

Coral bleaching is caused by environmental stress and susceptibility to bleaching stress varies among types of coral. The physiological properties of the algal symbionts (Symbiodinium spp.), especially extent of damage to PSII and its repair capacity, contribute importantly to this variability in stress susceptibility. The objective of the present study was to investigate the relationship between the growth rates and photosynthetic activities of six cultured strains of Symbiodinium spp. (clades A, B, C, D, and F) at elevated temperature (33 °C). We also observed the recovery of photodamaged-PSII in the presence or absence of a chloroplast protein synthesis inhibitor (lincomycin). The growth rates and photochemical efficiencies of PSII (Fv/Fm) decreased in parallel at high temperature in thermally sensitive strains, B-K100 (clade B followed by culture name) and A-Y106, but not in thermally tolerant strains, F-K102 and D-K111. In strains A-KB8 and C-Y103, growth declined markedly at high temperature, but Fv/Fm decreased only slightly. These strains may reallocate energy from growth to the repair of damaged photosynthetic machineries or protection pathways. Alternatively, since recoveries of photo-damaged PSII at 33 °C were modest in strains A-KB8 and C-Y103, thermal stressing of other metabolic pathways may have reduced growth rates in these two strains. This possibility should be explored in future research efforts.

show abstract

Section: Introductionmentioning

confidence: 48%

Temperature Effects on the Growth Rates and Photosynthetic Activities of Symbiodinium Cells

Karim

Nakaema

Hidaka

2015

JMSE

View full text Add to dashboard Cite

show abstract

“…Phylotype selection-We focused on four phylotypes of Symbiodinium that have previously been characterized for their photobiological Hennige et al 2009) and stress tolerance Suggett et al 2008;Ragni et al 2010) characteristics: three phylotypes from clade A (A1, A13, and A2) and one phylotype from clade B (B1). These phylotypes have previously been isolated from reef-building corals, as well as other host types, including jellyfish, soft corals, bivalves, gorgonian sea fans, and sea anemones (Freudenthal 1962;LaJeunesse 2001;Rogers and Davis 2006;Santos and LaJeunesse 2009), and identified in hospite across a range of geographic locations-including the Caribbean; western, eastern, and central Pacific; and the Red sea-apart from phylotype A13 (formally designated as A1.1 in Robison and Warner [2006] and LaJeunesse [2001], but now reclassified as A13 in LaJeunesse et al 2009) which, to date, has only been isolated in the Caribbean (LaJeunesse 2001).…”

Section: Methodsmentioning

confidence: 99%

“…The Symbiodinium genus is taxonomically diverse, with hundreds of phylotypes, or ''species,'' thought to exist across the world's oceans (Coffroth and Santos 2005). These phylotypes of Symbiodinium are able to occupy different environmental niches, most likely as a result of their substantial phylotypespecific range of physiological responses to environmental change (Hennige et al 2009) and stress Suggett et al 2008;Ragni et al 2010), as well as the generalist vs. specialist modes of specificity with their cnidarian hosts (Finney et al 2010;LaJeunesse et al 2010). Symbiodinium is, thus, an important model organism to examine genotypic-specific responses to environmental change; however, their potential sensitivity to OA is currently unknown.…”

mentioning

confidence: 99%

Differential effects of ocean acidification on growth and photosynthesis among phylotypes of Symbiodinium (Dinophyceae)

Brading

Warner

Davey

et al. 2011

Limnology & Oceanography

137

149

View full text Add to dashboard Cite

We investigated the effect of elevated partial pressure of CO 2 (pCO 2 ) on the photosynthesis and growth of four phylotypes (ITS2 types A1, A13, A2, and B1) from the genus Symbiodinium, a diverse dinoflagellate group that is important, both free-living and in symbiosis, for the viability of cnidarians and is thus a potentially important model dinoflagellate group. The response of Symbiodinium to an elevated pCO 2 was phylotype-specific. Phylotypes A1 and B1 were largely unaffected by a doubling in pCO 2 ; in contrast, the growth rate of A13 and the photosynthetic capacity of A2 both increased by , 60%. In no case was there an effect of ocean acidification (OA) upon respiration (dark-or light-dependent) for any of the phylotypes examined. Our observations suggest that OA might preferentially select among free-living populations of Symbiodinium, with implications for future symbioses that rely on algal acquisition from the environment (i.e., horizontal transmission). Furthermore, the carbon environment within the host could differentially affect the physiology of different Symbiodinium phylotypes. The range of responses we observed also highlights that the choice of species is an important consideration in OA research and that further investigation across phylogenetic diversity, for both the direction of effect and the underlying mechanism(s) involved, is warranted.

show abstract

“…Changing r i changes the maximal amount of C, N, and chlorophyll that one cell could contain. Secondly, the repair rate coefficients a Photosystem repair is a vital process in the protection against bleaching, and it has been speculated that variations in the ability of different coral species to photo-repair underlies the difference in bleaching susceptibility (Takahashi et al 2004Ragni et al 2010). In vitro bleaching 'sensitive' Symbiodinium have been shown to have a reduced photo-repair rate in comparison to 'tolerant' clades of Symbiodinium Ragni et al 2010).…”

Section: Methodsmentioning

confidence: 99%

“…Secondly, the repair rate coefficients a Photosystem repair is a vital process in the protection against bleaching, and it has been speculated that variations in the ability of different coral species to photo-repair underlies the difference in bleaching susceptibility (Takahashi et al 2004Ragni et al 2010). In vitro bleaching 'sensitive' Symbiodinium have been shown to have a reduced photo-repair rate in comparison to 'tolerant' clades of Symbiodinium Ragni et al 2010). Although in situ measurements of photo-repair are still sparse, it has been shown that the Symbiodinium associated with the bleaching-tolerant Porites astreoides had a higher repair rate than Symbiodinium associated with the bleaching-sensitive Monstastraea faveolata (Hennige et al 2011).…”

Section: Methodsmentioning

confidence: 99%

Modeling photoinhibition‐driven bleaching in Scleractinian coral as a function of light, temperature, and heterotrophy

Gustafsson

Baird

Ralph

2014

Limnology & Oceanography

View full text Add to dashboard Cite

It has been proposed that corals with symbiotic algae (Symbiodinium) bleach under thermal stress due to temperature-dependent inactivation of the Rubisco protein that impairs CO 2 uptake, causing a backlog of electrons that result in the formation of damaging Reactive Oxygen Species. We present a numerical model of this mechanism of photoinhibition for symbiotic algae residing within coral tissue. The resulting rate of bleaching depended on temperature, light intensity, and the rate of heterotrophic feeding. The model was validated using three independently published experimental data sets. The model was capable of capturing both the diurnal change in the state of the photosystem, as well as changes in the symbiont population and the coral host caused by different temperature, light, and feeding treatments. Elevated temperatures and light led to a degradation of the photosystem and the expulsion of symbiont cells. If the coral fed heterotrophically, this degradation of the photosynthetic apparatus was reduced, but still a clear decrease in maximum quantum yield (F v : F m ) and cell numbers was observed when the coral was exposed to elevated temperature. The reduction in chlorophyll content of cells at elevated temperatures and light was compared with the observational bleaching index Degree Heating Days (DHD). As quantified by DHD, the model was found to bleach under similar thermal stress regimes as field studies, except under elevated heterotrophic feeding conditions, which resulted in reduced severity of bleaching over a 90 d period.

show abstract

PSII photoinhibition and photorepair in Symbiodinium (Pyrrhophyta) differs between thermally tolerant and sensitive phylotypes

Cited by 106 publications

References 42 publications

Temperature Effects on the Growth Rates and Photosynthetic Activities of Symbiodinium Cells

Temperature Effects on the Growth Rates and Photosynthetic Activities of Symbiodinium Cells

Differential effects of ocean acidification on growth and photosynthesis among phylotypes of Symbiodinium (Dinophyceae)

Modeling photoinhibition‐driven bleaching in Scleractinian coral as a function of light, temperature, and heterotrophy

Contact Info

Product

Resources

About