Optical Properties of Corals Distort Variable Chlorophyll Fluorescence Measurements

Daniel Wangpraseurt, Mads Lichtenberg, Steven Jacques, Anthony W.D. Larkum, Michael Kühl

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Pulse-amplitude-modulated (PAM) fluorimetry is widely used in photobiological studies of corals, as it rapidly provides numerous photosynthetic parameters to assess coral ecophysiology. Coral optics studies have revealed the presence of light gradients in corals, which are strongly affected by light scattering in coral tissue and skeleton. We investigated whether coral optics affects variable chlorophyll (Chl) fluorescence measurements and derived photosynthetic parameters by developing planar hydrogel slabs with immobilized microalgae and with bulk optical properties similar to those of different types of corals. Our results show that PAM-based measurements of photosynthetic parameters differed substantially between hydrogels with different degrees of light scattering but identical microalgal density, yielding deviations in apparent maximal electron transport rates by a factor of 2. Furthermore, system settings such as the measuring light intensity affected F0, Fm , and Fv /Fm in hydrogels with identical light absorption but different degrees of light scattering. Likewise, differences in microalgal density affected variable Chl fluorescence parameters, where higher algal densities led to greater Fv /Fm values and relative electron transport rates. These results have important implications for the use of variable Chl fluorimetry in ecophysiological studies of coral stress and photosynthesis, as well as other optically dense systems such as plant tissue and biofilms.

Original languageEnglish (US)
Pages (from-to)1608-1619
Number of pages12
JournalPlant physiology
Volume179
Issue number4
DOIs
StatePublished - Apr 1 2019
Externally publishedYes

Fingerprint

Anthozoa
optical properties
Chlorophyll
corals
Fluorescence
fluorescence
chlorophyll
hydrocolloids
Light
light scattering
Fluorometry
Hydrogels
fluorometry
Electron Transport
optics
electron transfer
Microalgae
ecophysiology
Hydrogel
slabs

ASJC Scopus subject areas

  • Physiology
  • Genetics
  • Plant Science

Cite this

Wangpraseurt, D., Lichtenberg, M., Jacques, S., Larkum, A. W. D., & Kühl, M. (2019). Optical Properties of Corals Distort Variable Chlorophyll Fluorescence Measurements. Plant physiology, 179(4), 1608-1619. https://doi.org/10.1104/pp.18.01275

Optical Properties of Corals Distort Variable Chlorophyll Fluorescence Measurements. / Wangpraseurt, Daniel; Lichtenberg, Mads; Jacques, Steven; Larkum, Anthony W.D.; Kühl, Michael.

In: Plant physiology, Vol. 179, No. 4, 01.04.2019, p. 1608-1619.

Research output: Contribution to journalArticle

Wangpraseurt, D, Lichtenberg, M, Jacques, S, Larkum, AWD & Kühl, M 2019, 'Optical Properties of Corals Distort Variable Chlorophyll Fluorescence Measurements', Plant physiology, vol. 179, no. 4, pp. 1608-1619. https://doi.org/10.1104/pp.18.01275
Wangpraseurt D, Lichtenberg M, Jacques S, Larkum AWD, Kühl M. Optical Properties of Corals Distort Variable Chlorophyll Fluorescence Measurements. Plant physiology. 2019 Apr 1;179(4):1608-1619. https://doi.org/10.1104/pp.18.01275
Wangpraseurt, Daniel ; Lichtenberg, Mads ; Jacques, Steven ; Larkum, Anthony W.D. ; Kühl, Michael. / Optical Properties of Corals Distort Variable Chlorophyll Fluorescence Measurements. In: Plant physiology. 2019 ; Vol. 179, No. 4. pp. 1608-1619.
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