Polyphasic Systematics of the Fungicolous Genus Cladobotryum Based on Morphological, Molecular and Metabolomics Data

Abstract

(1) Background: Species of the anamorphic genus, Cladobotryum, are known for their fungicolous lifestyle, making them important mycopathogens in fungiculture. Many morphological, ecological, and molecular phylogenetic studies of the genus have been done to date, but taxonomic uncertainties and challenges still remain. Fungal secondary metabolites, being vastly diverse, are utilised as an extra tool in fungal systematics. Despite being studied for their potentially bioactive compounds, Cladobotryum species are insufficiently investigated regarding metabolomics. (2) Methods: The aim of this study is the identification of Greek strains of Cladobotryum by integrating morphological data, ITS-based phylogeny, and 1H NMR-based metabolomics into a polyphasic approach. (3) Results: Twenty-three strains, isolated from sporophores of macromycetes inhabiting diverse Greek ecosystems, were morphologically identified as Cladobotryum apiculatum, C. fungicola, C. mycophilum, C. varium, C. verticillatum, and Hypomyces rosellus (anamorph C. dendroides), whereas seven strains, which produced red-pigmented metabolites, presented an ambiguous taxonomic position at the species level. Molecular phylogenetics and metabolomics corroborated the morphological findings. (4) Conclusions: Thorough morphological study, ITS region-based phylogeny, and NMR-based metabolomics contribute complementarily to resolving the genus Cladobotryum systematics.

Genomic insights into the evolution and adaptation of secondary metabolite gene clusters in fungicolous species Cladobotryum mycophilum ATHUM6906

“…2c ). This positioning is also supported by other single locus-based phylogenetic analyses, in which the ITS was mainly used ( Põldmaa 2011 ; Milic et al . 2022 ).…”

“…1937 ). The presence of aurofusarin's BGC was expected in C. mycophilum strain ATHUM6906, since a previous work in genus Cladobotryum showed that C. mycophilum is basal to the monophyletic clade formed by species producing this metabolite ( Milic et al . 2022 ).…”

“…Notably, the BGC of aurofusarin, the most well-known metabolite characterizing the red-colored Cladobotryum species ( Milic et al . 2022 ), was located in scaffold 17 ( Fig.…”

“…The sexual state of certain Cladobotryum species is associated with the genus Hypomyces , while for the rest, their anamorphs (conidial or asexual states) are not correlated with any teleomorphs ( Rehner and Samuels 1995 ). Studies of C. mycophilum , the anamorph of Hypomyces odoratus , are focused on its diversity, distribution, and phylogenetic positioning within the genus, using gene regions of the internal transcribed spacer (ITS), the RNA polymerase II subunit (RPB1 and RPB2), and the translation elongation factor 1-alpha (TEF1) for barcoding, in addition to secondary metabolite profiling ( Põldmaa 2011 ; Milic et al . 2022 ).…”

“…2009 ), flavipucine and brunnescin ( Wagner et al . 1995 ), and various other secondary metabolites ( Milic et al . 2022 ).…”