LMU researchers have identified a set of proteins that enable plants to adjust their photosynthesis in response to fluctuating light intensities so as to make the best use of the light available.

Photosynthesis, the most important single biological process on Earth, is driven by sunlight. However, solar radiation is a fickle energy source, for the intensity of the light available in most environments is constantly changing - depending on factors such as the cloud cover and the distribution of shade. Now, LMU biologists led by Professor Peter Geigenberger, in collaboration with researchers at the Max Planck Institute for Molecular Plant Physiology in Potsdam and at the University of Paris, have identified a number of proteins that are essential for the ability of photosynthesis to adapt to fluctuating light levels. Their findings appear in the journal Molecular Plant.

For optimal growth, plants need to maintain a high and stable rate of photosynthesis, and to do so they must be able to react quickly to sudden changes in light intensity: In the event of an abrupt increase in light flux, the excess energy is either dissipated as heat or the energy is diverted to metabolic processes in order to avoid the formation of reactive oxygen species, which would damage the photosystems and other cell components. When the light intensity falls, leaf cells must minimize heat loss as quickly as possible and adjust the distribution of energy transfer to metabolic operations. "We have now demonstrated that enzymes called thioredoxins are intimately involved in these acclimation processes," says Geigenberger.

Read more at: http://phys.org/news/2016-12-adjust-photosynthesis-response-fluctuating-intensities.html#jCp