Combining O2 Microsensors and Fiber-Optic Technology to Measure Photo-Physiological Responses of Symbiodinium
Research output: Contribution to conference › Conference abstract for conference › Research
Standard
Combining O2 Microsensors and Fiber-Optic Technology to Measure Photo-Physiological Responses of Symbiodinium. / Ulstrup, Karin Elizabeth; Kühl, Michael; Ralph, Peter; Van Oppen, Madeleine; Bourne, David.
2008. Abstract from 11th International Coral Reef Symposium, Fort Lauderdale, Florida, United States.Research output: Contribution to conference › Conference abstract for conference › Research
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - ABST
T1 - Combining O2 Microsensors and Fiber-Optic Technology to Measure Photo-Physiological Responses of Symbiodinium
AU - Ulstrup, Karin Elizabeth
AU - Kühl, Michael
AU - Ralph, Peter
AU - Van Oppen, Madeleine
AU - Bourne, David
PY - 2008
Y1 - 2008
N2 - Corals associate with a diverse microbial assemblage of whichendosymbiotic and phototrophic microalgae, i.e. dinoflagellatesbelonging to the genetically diverse genus Symbiodinium, are bestknown. Traditional techniques to estimate photosynthesis activity suchas oxygen exchange and 14C-incorporation of Symbiodinium areconfounded by processes due to the coral host. In three case studies weemployed a novel approach using two technologies that enabledifferentiation of the photosynthesis activity of Symbiodinium, pulseamplitude-modulation (PAM) and O2 microsensors. The case studiesincluded i) monotypic Symbiodinium associating with a coral(Pocillopora damicornis), ii) a ciliate forming a brown band on the coralAcropora muricata, and iii) a genotypically diverse Symbiodiniumassociation with Acropora valida. In all instances, the combination offibre-optic technology and an O2 microelectrode enabled parallelmeasurements of gross photosynthesis rate and photosystem II quantumyield at the coral surface under steady-state conditions as a function ofincreasing irradiances. The studies showed large plasticity in photophysiologicalacclimation of Symbiodinium linked to light microclimateas well as motility (in the case of the ciliate) and Symbiodiniumgenotype (in the case of A. valida). In case i) and iii) there was nonlinearitybetween relative electron transport rate (rETR) and grossphotosynthesis measurements at moderate to high irradiances possiblydue to vertical heterogeneity of the symbionts in the tissue and/or theoperation of an alternative electron pathway such as cyclic electron flowaround PSII. Case ii) demonstrated that Symbiodinium ingested byciliates are photosynthetically competent and do not becomecompromised during the progression of the brown band zone. In contrastto case i) and iii) the symbionts produced relatively high grossphotosynthesis rate and rETR at moderate to high irradiance due togreater efficiency of light absorption caused by a higher density ofsymbionts in the ciliate.
AB - Corals associate with a diverse microbial assemblage of whichendosymbiotic and phototrophic microalgae, i.e. dinoflagellatesbelonging to the genetically diverse genus Symbiodinium, are bestknown. Traditional techniques to estimate photosynthesis activity suchas oxygen exchange and 14C-incorporation of Symbiodinium areconfounded by processes due to the coral host. In three case studies weemployed a novel approach using two technologies that enabledifferentiation of the photosynthesis activity of Symbiodinium, pulseamplitude-modulation (PAM) and O2 microsensors. The case studiesincluded i) monotypic Symbiodinium associating with a coral(Pocillopora damicornis), ii) a ciliate forming a brown band on the coralAcropora muricata, and iii) a genotypically diverse Symbiodiniumassociation with Acropora valida. In all instances, the combination offibre-optic technology and an O2 microelectrode enabled parallelmeasurements of gross photosynthesis rate and photosystem II quantumyield at the coral surface under steady-state conditions as a function ofincreasing irradiances. The studies showed large plasticity in photophysiologicalacclimation of Symbiodinium linked to light microclimateas well as motility (in the case of the ciliate) and Symbiodiniumgenotype (in the case of A. valida). In case i) and iii) there was nonlinearitybetween relative electron transport rate (rETR) and grossphotosynthesis measurements at moderate to high irradiances possiblydue to vertical heterogeneity of the symbionts in the tissue and/or theoperation of an alternative electron pathway such as cyclic electron flowaround PSII. Case ii) demonstrated that Symbiodinium ingested byciliates are photosynthetically competent and do not becomecompromised during the progression of the brown band zone. In contrastto case i) and iii) the symbionts produced relatively high grossphotosynthesis rate and rETR at moderate to high irradiance due togreater efficiency of light absorption caused by a higher density ofsymbionts in the ciliate.
M3 - Conference abstract for conference
Y2 - 7 July 2008 through 11 July 2008
ER -
ID: 5467230