Abstract
The impact of a heterogeneous distribution of actinic light within a leaf chamber for photosynthetic measurements by gas exchange on the photosynthesis-irradiance relationship was investigated. High-resolution light distributions were measured over the area of a commercially available clamp-on leaf chamber equipped with build-in red and blue LEDs, as well as over the area of a custom-made leaf chamber with external light source, using a low-cost digital camera and freely available software. The impact of the measured heterogeneity on the photosynthesis-irradiance response curve was calculated for two realistic scenarios. When the average light intensity over the leaf chamber area was estimated accurately, heterogeneity had minor effects on the photosynthesis-irradiance response curve. However, when the irradiance was measured in the chamber centre, which is common practice, and assumed to be homogeneous, for both leaf chambers the photosynthesis-irradiance response curve was subject to considerable error and led to serious underestimation of the light-limited quantum yield of photosynthesis. Additionally, mixed light sources with different heterogeneity patterns per light source, such as in the clamp-on leaf chamber, potentially increase errors due to heterogeneous physiological responses to light spectrum. High-resolution quantification of the leaf-chamber light distribution enables calculation of the correct average light intensity and already resolves the most pressing problems associated with heterogeneity. To exclude any light-distribution related errors in gas-exchange measurements a leaf chamber and actinic irradiance source design with a homogeneous light distribution is an absolute requirement.
Similar content being viewed by others
Abbreviations
- P max :
-
light saturated gross assimilation rate
- P N :
-
net assimilation rate
- R D :
-
dark respiration
- SD:
-
standard deviation
- α:
-
quantum yield for CO2 fixation
- θ:
-
scaling constant for curvature light-response curve
References
Baker, N.R., Harbinson, J., Kramer, D.M.: Determining the limitations and regulation of photosynthetic energy transduction in leaves. — Plant Cell Environ. 30: 1107–1125, 2007.
Chen, C.P., Zhu, X.G., Long, S.P.: The effect of leaf-level spatial variability in photosynthetic capacity on biochemical parameter estimates using the farquhar model: A theoretical analysis. — Plant Physiol. 148: 1139–1147, 2008.
Dubois, J.J.B., Fiscus, E.L., Booker, F.L., Flowers, M.D., Reid, C.D.: Optimizing the statistical estimation of the parameters of the Farquhar-von Caemmerer-Berry model of photosynthesis. — New Phytol. 176: 402–414, 2007.
Evans, J.R.: The dependence of quantum yield on wavelength and growth irradiance. — Aust. J. Plant Physiol. 14: 69–79, 1987.
Farquhar, G.D., von Caemmerer, S., Berry, J.A.: A Biochemical model of photosynthetic CO2 assimilation in leaves of C3 species. — Planta 149: 78–90, 1980.
Flexas, J., Diaz-Espejo, A., Berry, J.A., Cifre, J., Galmes, J., Kaidenhoff, R., Medrano, H., Ribas-Carbo, M.: Analysis of leakage in IRGA’s leaf chambers of open gas exchange systems: quantification and its effects in photosynthesis parameterization. — J. Exp. Bot. 58: 1533–1543, 2007.
Inada, K.: Action spectra for photosynthesis in higher plants. — Plant Cell Physiol. 17: 355–365, 1976.
Laisk, A., Oja, V.: Dynamics of leaf photosynthesis: Rapid response measurements and their interpretations. — CSIRO Publishing, Collingwood 1998.
Long, S.P., Postl, W.F., Bolharnordenkampf, H.R.: Quantum yields for uptake of carbon dioxide in C3 vascular plants of contrasting habitats and taxonomic groupings. — Planta 189: 226–234, 1993.
McCree, K.J.: Action spectrum, absorptance and quantum yield of photosynthesis in crop plants. — Agr. Meteorol. 9: 191–216, 1972.
Morison, J.I.L., Gallouet, E., Lawson, T., Cornic, G., Herbin, R., Baker, N.R.: Lateral diffusion of CO2 in leaves is not sufficient to support photosynthesis. — Plant Phys. 139: 254–266, 2005.
Nejad, A.R., Harbinson, J., van Meeteren, U.: Dynamics of spatial heterogeneity of stomatal closure in Tradescantia virginiana altered by growth at high relative air humidity. — J. Exp. Bot. 57: 3669–3678, 2006.
Oya, V., Laisk, A.: Adaptation of the photosynthesis apparatus to the light profile in leaf. — Soviet Plant Phys. 23: 381–386, 1976.
Pons, T.L., Welschen, R.A.M.: Overestimation of respiration rates in commercially available clamp-on leaf chambers. Complications with measurement of net photosynthesis. — Plant Cell Environ. 25: 1367–1372, 2002.
Rodeghiero, M., Niinemets, U., Cescatti, A.: Major diffusion leaks of clamp-on leaf cuvettes still unaccounted: how erroneous are the estimates of Farquhar et al. model parameters? — Plant Cell Environ. 30: 1006–1022, 2007.
Sharkey, T.D., Raschke, K.: Effect of light quality on stomatal opening in leaves of Xanthium strumarium L. — Plant Phys. 68: 1170–1174, 1981.
Singsaas, E.L., Ort, D.R., DeLucia, E.H.: Variation in measured values of photosynthetic quantum yield in ecophysiological studies. — Oecologia 128: 15–23, 2001.
Terashima, I.: Dorsoventrality in photosynthetic light response curves of a leaf. — J. Exp. Bot. 37: 399–405, 1986.
Thornley, J.H.M.: Mathematical models in plant physiology: a quantitative approach to problems in plant and crop physiology. — Acad. Press, London 1976.
Willmer, C., Fricker, M.: Stomata. — Chapmann and Hall, London 1996.
Zeiger, E.: Light perception in guard cells. — Plant Cell Environ. 13: 739–744, 1990.
Acknowledgements
This research is supported by the Dutch Technology Foundation STW, applied science division of NWO and the Technology Program of the Ministry of Economic Affairs, Philips and Plant Dynamics BV. We are grateful to Joost Ruijsch, Evert Janssen and Gradus Leenders for their contribution in equipment development. Helpful comments were provided by users of the CHDK-RAW internet-forum.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Hogewoning, S.W., Trouwborst, G., Harbinson, J. et al. Light distribution in leaf chambers and its consequences for photosynthesis measurements. Photosynthetica 48, 219–226 (2010). https://doi.org/10.1007/s11099-010-0027-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11099-010-0027-2