Toward autonomous measurements of photosynthetic electron transport rates: an evaluation of active fluorescence-based measurements of photochemistry

Silsbe, Greg M.; Oxborough, Kevin; Suggett, David J.; Forster, Rodney M.; Ihnken, Sven; Komárek, Ondřej; Lawrenz, Evelyn; Prášil, Ondřej; Röttgers, Rüdiger; Šicner, Michal; Simis, Stefan G.H.; Van Dijk, Mark A.; Kromkamp, Jacco C.

Abstract

This study presents a methods evaluation and intercalibration of active fluorescence-based measurements of the quantum yield (ϕʹ 0 PSII) and absorption coefficient (aPSII) of photosystem II (PSII) photochemistry. Measurements of ϕʹ PSII , aPSII, and irradiance (E) can be scaled to derive photosynthetic electron transport rates (P e ), the process that fuels phytoplankton carbon fixation and growth. Bio-optical estimates of ϕ PSII and aPSII were evaluated using 10 phytoplankton cultures across different pigment groups with varying bio-optical absorption characteristics on six different fast-repetition rate fluorometers that span two different manufacturers and four different models. Culture measurements of ϕʹ PSII and the effective absorption cross section of PSII photochemistry (σPSII, a constituent of aPSII) showed a high degree of correspondence across instruments, although some instrument-specific biases are identified. A range of approaches have been used in the literature to estimate aPSII(λ) and are evaluated here.With the exception of ex situ aPSII(λ) estimates from paired σPSII and PSII reaction center concentration ([RCII]) measurements, the accuracy and precision of in situ aPSII(λ) methodologies are largely determined by the variance of method-specific coefficients. The accuracy and precision of these coefficients are evaluated, compared to literature data, and discussed within a framework of autonomous P e measurements. This study supports the application of an instrument-specific calibration coefficient (KR) that scales minimum fluorescence in the dark (F 0 ) to aPSII as both the most accurate in situ measurement of aPSII, and the methodology best suited for highly resolved autonomous P e measurements.VC 2014 Association for the Sciences of Limnology and Oceanography.

Citation

Silsbe, G. M., Oxborough, K., Suggett, D. J., Forster, R. M., Ihnken, S., Komárek, O., …Kromkamp, J. C. (2015). Toward autonomous measurements of photosynthetic electron transport rates: an evaluation of active fluorescence-based measurements of photochemistry. Limnology and oceanography, methods ASLO, 13(3), 138-155. https://doi.org/10.1002/lom3.10014

• Journal Article Type: Article
• Acceptance Date: Jan 20, 2015
• Online Publication Date: Mar 18, 2015
• Publication Date: 2015-03
• Deposit Date: Apr 16, 2015
• Publicly Available Date: Mar 20, 2018
• Journal: Limnology and oceanography : methods
• Electronic ISSN: 1541-5856
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 3
• Pages: 138-155
• DOI: https://doi.org/10.1002/lom3.10014
• Keywords: Photosynthetic electron transport rates; Photochemistry; Fluorescence
• Public URL: https://hull-repository.worktribe.com/output/372581
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1002/lom3.10014/references
• Additional Information: Copy of article first published in: Limnology and oceanography : methods, 2015, v. 13.