Genome And Secondary Metabolism Of Plant Endophytic Fungus Pestalotiopsis Fici

Plant endophytic fungus is an important source of bioactive natural products. Pestalotiopsis fici Steyaert W106-1as an endophyte of tea produces numerous novel secondary metabolites, and some of them might be important as lead compounds for future pharmaceutics. However, endophytic lifestyle, mystery of richness of secondary metabolites, and regulation of secondary metabolism of P. fici as a typical endophyte have not been comprehensive understood. Genome and transcriptome have been important approaches to study biology and secondary metabolism. In this study, the endophytic life strategy of P. fici and its richness of secondary were bioimformatically illustrated from genome and transcriptome. The regulation of the key secondary metabolites was studied by gene functional determination. The main results were as follows:1. General genome features of P. fci. The genome size of P. fici was52Mb, and a total of15,413genes were predicted. Transposable elements (TEs) made up only1.54%of the genome of P. fici, and repeat-induced point mutation (RIP) in the P. fici genome is heavy. The P. fici genome contained more multigene families, compared with those of other reference ascomyceteous fungi in this study. However, the P. fici genome contained a large number of replicated gene pairs with amino acid identities below80%.2. Endophytic life strategy of P. fici. The abundant carbohydrate-active enzymes especially significantly expanding pectinases allow the fungus to utilize the limited intercellular nutrients within the host plants, suggesting adaptation of the fungus to endophytic lifestyle. The expanded transporter gene families enhance the ability of the fungus to live in the nutrient-limited niche and to interact with the host plant.3. The abundant secondary metabolites of P. fici. A total of97core genes and74gene clusters encoding for secondary metabolite biosynthesis have been identified. The putative Diels-Alderase genes of Diels-Alder reaction have undergone expansion. The high diversity of polyketide synthase genes may have resulted from gene duplication and horizontal gene transfer.4. Regulation of important secondary metabolites. A homology search of the P. fici genome with the bZIP protein RsmA, involved in secondary metabolism and the oxidative stress response in Aspergillus nidulans, identified PfZipA. Deletion of PfzipA resulted in a strain that displayed resistant to the oxidative reagents tert-buty1hydroperoxide (tBOOH), diamide, and menadione sodium bisulphite (MSB), but increased sensitivity to H2O2as compared to wild type (WT). Without and with oxidative treatment, some compounds productions of theâ–³PfzipA strain are different from that of the wild type strain. The results suggest that PfZipA regulation of SM is involved in oxidative stress pathways. The genome data of P. fici not only provide a comprehensive understanding of the endophytic lifestrategies and the richness of secondary metabolites of endophytic fungus, but also facilitate futurestudies into biosynthesis pathway and regulation of secondary metabolite, mining novel bioactivesecondary metabolites of plant endophyte and plant-endophyte interactions.