Role of peptides for cellular differentiation and host interaction of N. punctiforme

• Applicant: Professorin Dr. Elke Dittmann-Thünemann
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2011 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 211281368

The strain Nostoc punctiforme is a filamentous, nitrogen-fixing cyanobacterium, whose vegetative cells can mature in four different directions. N. punctiforme has a very broad symbiotic capacity and interacts with diverse plant species. The strain ATCC29133 is capable of producing a variety of secondary metabolites, including some of the nonribosomal peptide and polyketide classes. Our preliminary investigations suggest a role of different metabolites in the orchestration of cellular differentiation events and communication with symbiotic hosts. In the proposed project we intend to specifically look at two types of peptides: nostopeptolide(s) and anabaenopeptin. We aim to construct mutants and characterize those using microscopy, HPLC and growth curves. We will specifically look at the cellular differentiation cycle under diazotrophic conditions. We will also try to complement phenotypic effects with isolated compounds. We intend to compare the symbiotic capacity of wild type and mutant strains with different symbiotic hosts. Finally, we are planning to visualize the temporal and spatial distribution of nostopeptolide and anabaenopeptin in different cell types, differentiation steps and during symbiosis using MALDI imaging. The results of the proposed project can shed some light on the communication processes in the exceptional life cycle of N. punctiforme and are potentially interesting for scientists working on symbiosis, communication, differentiation and natural products in microorganisms.

• DFG Programme: Research Grants