Intersystem photosynthetic redox signals in retrograde chloroplast-to-nucleus communication of higher plant cells

• Applicant: Professor Dr. Thomas Pfannschmidt
• Subject Area: Plant Physiology
• Term: from 2007 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 29017492

Environmental fluctuations in plant illumination affect the efficiency of the photosynthetic electron transport and induce characteristic changes in the redox state of plastoquinone and thioredoxin. These redox changes initiate molecular responses which acclimate the photosynthetic process to the residing conditions and help the plant to survive in an everchanging environment. It is known that this functional feed-back mechanism involves a complex signalling network which controls plastid and nuclear genes, but how this network functions is largely unknown. Especially the control of nuclear genes is complex since it requires (a) signalling cascade(s) which leave(s) the organelle. Redox signals, therefore, represent a novel class of retrograde signals. In microarrays we identified the target genes and the velocity of the signals indicating that redox signals integrate photosynthesis, respiration, carbohydrate metabolism and tetrapyrrole and lipid biosynthesis. We aim i) to demonstrate that this transcriptional regulation produce functional outcomes in the respective cellular processes and ii) to identify the involved signalling components by novel mutant screens and promoter-protein interaction assays.

• DFG Programme: Research Units
• Subproject of: FOR 804: Retrograde Signalling in Plants
• International Connection: France