Laboratoř fotosyntézy
Skupina Ondřeje Prášila
Mikrobiální fotosyntéza
Nitrogen fixation in diazotrophic cyanobacteria
Regulation of photosynthesis in diazotrophic cyanobacteria
We have been studying interplay between photosynthesis and nitrogen fixation in cyanobacteria since 2000, when Ilana Berman-Frank visited the laboratory of Ivan Šetlík to perform single-cell measurements of variable fluorescence of marine diazotrophic cyanobacterium Trichodesmium during diel cycle. This put her together also with Hendrik Küpper, then a PhD student of Ivan. Since these pioneering experiments we have enjoyed many years of fruitful collaboration between Třeboň, Konstanz and Tel Aviv. We focus on Trichodesmium, but we did studies also on other diazotrophs - Anabaena, Cyanothece and Crocosphaera. In our studies, we often use advantages of the Fluorescence Kinetic Microscopy (FKM) that allows us to study photosynthetic activities on the single cell levels.
Major outcomes:
- hypothesis on the transitional uncoupling of light harvesting phycobiliproteins in Trichodesmium to allow for nitrogen fixation [1,2,4]
- effects of iron limitation on regulation of photosynthesis in Trichodesmium [3]
- photoacclimation in Trichodesmium [5]
- effects of elevated CO2 on aquatic diazotrophs
RESULTS:
- Berman-Frank, I., Lundgren, P., Chen, Y-B., Küpper, H., Kolber, Z., Bergman, B., Falkowski, P.: Segregation of nitrogen fixation and oxygen photosynthesis in the marine cyanobacterium Trichodesmium. - Science 294, 1534-1537, 2001
- Küpper, H., Ferimazova, N., Šetlík, I., Berman-Frank, I.: Traffic lights in Trichodesmium. Regulation of photosynthesis for nitrogen fixation studied by chlorophyll fluorescence kinetics microscopy. - Plant Physiology 135, 2120-2133, 2004.
- Küpper, H., Šetlík, I., Seifert, S., Prášil, O., Šetlíková, E., Strittmatter, M., Levitan, O., Lohscheider, J., Adamska, I., Berman-Brank, I.: Iron limitation in the marine cyanobacterium Trichodesmium reveals new insights into regulation of photosynthesis and nitrogen fixation. – New Phytologist 179, 784-798, 2008.
-
Küpper, H., Andersen, E., Wiegert, S., Šimek, M., Leitenmaier, B., Šetlík, I.: Reversible coupling of individual phycobiliprotein isoforms during state transitions in the cyanobacterium Trichodesmium analysed by single-cell fluorescence kinetic measurements. – Biochimica et Biophysica Acta 1787, 155-167, 2009.
-
Andersen, E., Lohscheider, J., Šetlíková, E., Adamska, I., Šimek, M., Küpper, H.: Acclimation of Trichodesmium erythraeum ISM101 to high and low irradiance analysed on the physiological, biophysical and biochemical level. – New Phytologist 185, 173-188, 2010