Genomic mining of plant-induced secondary metabolites in symbiotic cyanobacteria

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Nitrogen-fixing cyanobacteria of the species Nostoc punctiforme are attractive partners and found in manifold symbioses with different plants and fungi. The filamentous cyanobacteria feature one of the most sophisticated life styles in the bacterial world and are capable of differentiating into four distinct cell types. Genome sequencing of N. punctiforme has revealed a large number of secondary metabolite gene clusters. Most of the clusters are orphan, i.e. the associated metabolites are currently unknown. MALDI-Imaging studies of N. punctiforme in symbiotic association with Gunnera manicata or in the neighborhood of the symbiotic partner Blasia pusilla have revealed a reprogramming of the secondary metabolome upon symbiotic interactions and indicate an up regulation of so far cryptic compounds in planta. The aims of the current project are1) To identify metabolites and biosynthetic gene clusters up regulated in planta2) To survey the transcriptional reprogramming of N. punctiforme in the neighborhood of B. pusilla3) To assess whether the reprogramming of the secondary metabolome is host- and strain-specific4) To structurally elucidate so far cryptic compounds from N. punctiforme5) To analyze the role of secondary metabolites in plantaThe results of this project are expected to provide new insights into the governing chemistry balancing cellular differentiation and symbiotic interactions of N. punctiforme. Moreover, we hope to uncover entirely new metabolite families for cyanobacteria and to estimate their biotechnological potential.