Group Leader

Dr. Ute Armbruster
Dr. Ute Armbruster
Phone:+49 331 567-8353


Light intensity in a corn field

Changes in light intensity over time in a corn field canopy.

Department Bock

Regulation of Photosynthesis

The group of Dr. Ute Armbruster aims to identify and characterize regulatory mechanisms of photosynthesis. Particular focus is on the question of how photosynthesis is regulated to achieve efficiency in fluctuating light conditions.

<p>Snapshot of light intensity changes in a corn field canopy</p> Zoom Image

Snapshot of light intensity changes in a corn field canopy

Most land plants live in very dynamic environments with frequently changing temperature, sunlight, water and nutrient availabilities. Especially sunlight, the energy source of photosynthesis and thus plant growth and reproduction, can undergo the most massive fluctuations on a very short time scale. Despite the ecological and economical importance of habitats with strong light fluctuations (i.e. forests and crop fields), to date very little effort has been directed towards the elucidation of molecular mechanisms that regulate photosynthesis in response to rapid, frequent and massive changes in light intensity.

Which regulatory mechanisms facilitate photosynthetic efficiency in fluctuating light?

The efficiency of photosynthesis in environments with frequently changing light intensities is tightly linked to the speed, with which the system can switch between photoprotection in excess light (to avoid photo-oxidative stress) and high quantum yield of photosynthesis in limiting light. The thylakoid K+/H+ antiporter 3 (KEA3) increases photosynthetic efficiency in fluctuating light by accelerating the downregulation of photoprotective energy dissipation in limiting light periods (Armbruster et al., 2014). One objective of the Armbruster group is to gain a deeper understanding of the functional and regulatory networks that KEA3 is involved in.

<p>Chlorophyll a fluorescence analysis of <em>Arabidopsis thaliana</em> plants to determine photosynthetic efficiency.</p> Zoom Image

Chlorophyll a fluorescence analysis of Arabidopsis thaliana plants to determine photosynthetic efficiency.

A further objective of the group is the identification of additional key regulatory mechanisms for photosynthesis in fluctuating light by using forward and reverse genetics in the model plant species Arabidopsis thaliana. The molecular function of newly identified components will then be further elucidated with spectroscopic, biochemical, molecular and cell biological approaches.

Armbruster, U., Carrillo, L.R., Venema, K., Pavlovic, L., Schmidtmann, E., Kornfeld, A.,  Jahns, P., Berry, J.A., Kramer, D.M., Jonikas, M.C. (2014) Ion antiport accelerates photosynthetic acclimation in fluctuating light environments. Nature Communications, 5:5439 doi: 10.1038

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