DBG · Promoting young researchers

Tilman Jacob (Martin-Luther-Universität Halle-Wittenberg)

Tilman Jacob's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Halle University in the year 2023 with the title:

Analyses of DNA binding activities of PIF4 haplotypes and mutants

Tilman Jacob established an in vitro assay to investigate the binding of different naturally occurring PIF4 haplotypes to the promoter of YUCCA8.

Understanding the molecular adaptation mechanisms of plants to increased ambient temperatures is crucial for the generation of future crops which are resilient to global warming. In the model plant Arabidopsis thaliana, the transcription factor PHYTOCHROME INTERACTING FACTOR 4 (PIF4) is a major coordinator of growth and development in response to light and temperature.

To make use of the natural genetic variation among different Arabidopsis ecotypes for the investigation of PIF4’s molecular function, a set of six naturally occurring PIF4 haplotypes was selected that assemble different combinations of frequently occurring single nucleotide polymorphisms (SNPs). Jacob established a pipeline for the recombinant expression of these PIF4 haplotypes in Escherichia coli and performed in vitro electrophoretic mobility shift assays (EMSAs) to study their DNA binding activities using the YUCCA8 promoter (pYUC8).

He could demonstrate that all evaluated natural PIF4 haplotypes were able to specifically bind pYUC8, in contrast to an artificially created PIF4 mutant with disrupted DNA-binding domain. Binding activities varied among the assessed natural haplotypes, but the assay was not robust enough to detect reproducible quantitative differences.

Nevertheless, the results represent a starting point for a more comprehensive molecular analysis of the PIF4 haplotypes, which will contribute to the overall understanding of PIF4’s molecular function and extend Arabidopsis thermoregulation research beyond the exclusive investigation of the Col-0 accession.

___

Tilman Jacob conducted this work at the institute for agricultural and nutritional sciences (IAEW) in the crop physiology laboratory of Prof. Dr. Marcel Quint, under the supervision of Dr. Lennart Eschen-Lippold.