Computational Analysis Reveals Industrial Natural Products and Toxins in Charcoal Rot Pathogen, Macrophomina phaseolina

The fungal polyketide synthases (PKS) are responsible for the biosynthesis of several polyketide natural products, mycotoxins, pigments, etc. In the present times, we use computational tools to gain insight into polyketide natural products that may contribute to the metabolic versatility of this important phytopa-thogenic filamentous fungi. In total, we have identified 17 type-I PKS related gene clusters from the Macro-phomina phaseolina genome. Among these 27 ketosyn-thase (KS) domains have been retrieved and used for the study. The study reveals that genome of M. phase-olina comprises non-reducing (NR), partially reducing (PR) and reducing (R) type of polyketides, and are clustered into three clades and several subclades. The phylogenetic analysis of KS domain sequences of M. phaseolina indicates that some PKS sequences are most closely related to polyketide natural product homologs such as lovastatin diketide, mycotoxins (fumonisin, citrinin and patulin) and pigment melanin. We also found eight orphan KS domains from three reducing PKS, i.e. MPH10374, MPH10375 and MPH10376. The study represents a potential novel source of industri-ally important polyketide natural products.