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Anna Sophie Stasche (Universität Bielefeld)

Anna Sophie Stasche's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Universität Bielefeld in the year 2022

Title: Transcriptional control of photosynthetic gene expression in Arabidopsis thaliana

Stasche found out that the photosynthetic transcriptional regulation in Arabidopsis thaliana is modular. To know about this regulation is crucial for future biotechnological improvements of cropplant yields.

Starting with the hypothesis that “photosynthetic transcriptional regulation” is regulation of either the Calvin Benson Bassham cycle, the photosynthetic electron transport chain or possibly both, a meta analysis of publicly available data of known photosynthetic transcriptionfactors GOLDEN 2-LIKE 1(GLK1), GOLDEN 2-LIKE2 (GLK2), GATANITRATE-INDUCIBLECARBONMETABOLISM-INVOLVED (GNC), GNC-LIKE (GNL), ELONGATEDHYPOCOTYL 5 (HY5) and PYTOCHROMEINTERACTINGFACTORs (PIFs)1, 3, 4 and 5 was performed. In the meta analysis binding information in the form of ChIP – and DAP -seq experiments, as well as microarray and RNA-seq differential transcriptome data of overexpression and knock-out mutants was incorporated.

The meta analysis revealed several positive and negative instances of transcriptional regulation between the different analysed TFs, suggesting that the regulatory network upstream of photosynthetic genes is looped and net-like rather than the previously assumed hierarchical organisation. In accordance with existing literature the four PIF family TFs were found to be general suppressors of photosynthesis. While the remaining TFs act on different sets of photosynthetis genes with for example expression of genes encoding parts of the photosynthetic antenna likely being upregulated by GLKs and downregulated by GNC. In contrast expression of transcripts of photorespiration related genes is indicated to be suppressed by GLKs and increased by GNC. The photosynthetic genes can be devided into different modules based on the regulatory patterns seen in the metaanalysis.

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Anna Sophie Stasche conducted this work at the faculty of biology in the work group „computational biology“ of Prof. Dr. Andrea Bräutigam.