Dr Rita Zrenner
Group: Nucleotides and Sugars
New position: Research Group Secondary Metabolites, IGZ Großbeeren
This group studied the interdependence of nucleotide and sugar metabolism in plant growth and development with an emphasis on the turnover of pyrimidines and the partitioning of UDP-glucose. Arabidopsis thaliana and Solanaceous species were used as model systems.
Nucleotides are involved as basic participants in numerous metabolic reactions, providing co-substrates and energy rich precursors for many biosynthetic processes. During processes of photosynthesis and respiration, the purine nucleotide ATP is produced as the major triphosphate for the general conservation of chemical energy. In plants, UTP is also required as co-substrate to form the highly activated, central metabolite UDP-glucose during the essential processes of sucrose synthesis. In contrast, when sucrose is broken down by the plant-specific enzyme sucrose synthase, UDP acts as a substrate and UDP-glucose is formed. In addition, UDP-glucose is not only important in sucrose turnover but is also the major precursor for nearly all carbohydrate polymers of plant cell walls.
The need of a plant for purine (ATP) and pyrimidine (UTP, UDP) nucleotides varies depending on the tissue and the physiological and developmental state. Not only the control of overall energy charge is crucial for plant metabolism but a tight regulation of the specific purine and pyrimidine nucleotide pools is also needed. However, little is known about the regulation of nucleotide turnover and energy transfer between nucleotides in plants.
The aim of the research was to elucidate the interdependence between nucleotide and sugar metabolism in plant growth and development.