Spectral effects on Symbiodinium photobiology studied with a programmable light engine

• Published in: PloS one Vol. 9; no. 11; p. e112809
• Main Authors: Wangpraseurt, Daniel, Tamburic, Bojan, Szabó, Milán, Suggett, David, Ralph, Peter J, Kühl, Michael
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12.11.2014; Public Library of Science (PLoS)
• Subjects: Algae; Animals; Anthozoa - physiology; Biological Evolution; Biology; Biology and Life Sciences; Climate change; Comparative analysis; Comparative studies; Coral Reefs; Dinoflagellida - metabolism; Dinoflagellida - physiology; Earth Sciences; Ecology and Environmental Sciences; Ecosystem biology; Ecosystems; Electron transport; Electron Transport - physiology; Evolution; Hydrologic cycle; Irradiance; Laboratories; Light; Light sources; Microorganisms; Optical properties; Optics; Oxygen - metabolism; Photobiology; Photobiology - methods; Photosynthesis; Photosynthesis - physiology; Photosystem II; Plant biochemistry; Reefs; Respiration; Spectra; Spectral resolution; Studies; Stylophora pistillata; Symbiodinium; Symbiosis - physiology; Sydney New South Wales Australia; Australia; Singapore
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0112809

The spectral light field of Symbiodinium within the tissue of the coral animal host can deviate strongly from the ambient light field on a coral reef and that of artificial light sources used in lab studies on coral photobiology. Here, we used a novel approach involving light microsensor measurements and a programmable light engine to reconstruct the spectral light field that Symbiodinium is exposed to inside the coral host and the light field of a conventional halogen lamp in a comparative study of Symbiodinium photobiology. We found that extracellular gross photosynthetic O2 evolution was unchanged under different spectral illumination, while the more red-weighted halogen lamp spectrum decreased PSII electron transport rates and there was a trend towards increased light-enhanced dark respiration rates under excess irradiance. The approach provided here allows for reconstructing and comparing intra-tissue coral light fields and other complex spectral compositions of incident irradiance. This novel combination of sensor technologies provides a framework to studying the influence of macro- and microscale optics on Symbiodinium photobiology with unprecedented spectral resolution.