Human and Plant Fungal Pathogens: The Role of Secondary Metabolites

Secondary metabolites (SM) are small organic molecules produced by various microorganisms (mainly fungi and actinobacteria, among others) through the action of large enzymes like nonribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) or by enzymes like dimethylallyl transferases and prenyltransferases. These special metabolites are in general not essential for growth but are believed to be advantageous for the producing organism under certain conditions and in distinct habitats. In fungi, the genes responsible for SM biosynthesis are usually arranged in clusters [1], which are often found at the end of the chromosomes in subtelomeric regions [2,3].