Two new species of Diaporthe (Diaporthaceae, Diaporthales) associated with tree cankers in the Netherlands

Diaporthe (Diaporthaceae, Diaporthales) is a common fungal genus inhabiting plant tissues as endophytes, pathogens and saprobes. Some species are reported from tree branches associated with canker diseases. In the present study, Diaporthe samples were collected from Alnus glutinosa, Fraxinus excelsior and Quercus robur in Utrecht, the Netherlands. They were identified to species based on a polyphasic approach including morphology, pure culture characters, and phylogenetic analyses of a combined matrix of partial ITS, cal, his3, tef1 and tub2 gene regions. As a result, four species (viz. Diaporthe pseudoalnea sp. nov. from Alnus glutinosa, Diaporthe silvicola sp. nov. from Fraxinus excelsior, D. foeniculacea and D. rudis from Quercus robur) were revealed from tree branches in the Netherlands. Diaporthe pseudoalnea differs from D. eres (syn. D. alnea) by its longer conidiophores. Diaporthe silvicola is distinguished from D. fraxinicola and D. fraxini-angustifoliae by larger alpha conidia.

Enemy or ally: a genomic approach to elucidate the lifestyle of Phyllosticta citrichinaensis

Members of the fungal genus Phyllosticta can colonize a variety of plant hosts, including several Citrus species such as Citrus sinensis (orange), Citrus limon (lemon), and Citrus maxima (pomelo). Some Phyllosticta species have the capacity to cause disease, such as Citrus Black Spot, while others have only been observed as endophytes. Thus far, genomic differences underlying lifestyle adaptations of Phyllosticta species have not yet been studied. Furthermore, the lifestyle of Phyllosticta citrichinaensis is ambiguous, as it has been described as a weak pathogen but Kochs postulates may not have been established and the presence of this species was never reported to cause any crop or economic losses. Here, we examined the genomic differences between pathogenic and endophytic Phyllosticta spp. colonizing Citrus and specifically aimed to elucidate the lifestyle of Phyllosticta citrichinaensis. We found several genomic differences between species of different lifestyles, including groups of genes that were only present in pathogens or endophytes. We also observed that species, based on their carbohydrate active enzymes, group independent of their phylogenetic association, and this clustering correlated with trophy prediction. Phyllosticta citrichinaensis shows an intermediate lifestyle, sharing genomic and phenotypic attributes of both pathogens and endophytes. We thus present the first genomic comparison of multiple citrus-colonizing pathogens and endophytes of the genus Phyllosticta, and therefore provide the basis for further comparative studies into the lifestyle adaptations within this genus.

Phenotypic Recovery of a Heterobasidion Isolate Infected by a Debilitation-Associated Virus Is Related to Altered Host Gene Expression and Reduced Virus Titer

The fungal genus Heterobasidion includes forest pathogenic species hosting a diverse group of partitiviruses. They include the host debilitating Heterobasidion partitivirus 13 strain an1 (HetPV13-an1), which was originally observed in a slowly growing H. annosum strain 94233. In this study, a relatively fast-growing sector strain 94233-RC3 was isolated from a highly debilitated mycelial culture of 94233, and its gene expression and virus transcript quantities as well as the genomic sequence of HetPV13-an1 were examined. The sequence of HetPV13-an1 genome in 94233-RC3 was identical to that in the original 94233, and thus not the reason for the partial phenotypic recovery. According to RNA-seq analysis, the HetPV13-an1 infected 94233-RC3 transcribed eight genes differently from the partitivirus-free 94233-32D. Three of these genes were downregulated and five upregulated. The number of differentially expressed genes was considerably lower and the changes in their expression were small compared to those of the highly debilitated original strain 94233 with the exception of the most highly upregulated ones, and therefore viral effects on the host transcriptome correlated with the degree of the virus-caused debilitation. The amounts of RdRp and CP transcripts of HetPV13-an1 were considerably lower in 94233-RC3 and also in 94233 strain infected by a closely related mildly debilitating virus HetPV13-an2, suggesting that the virus titer would have a role in determining the effect of HetPV13 viruses on their hosts.

A novel Mariannaea species isolated from decayed pine needles in Japan

A strain of the fungal genus Mariannaea, isolated from decayed leaves of Japanese red pine (Pinus densiflora), was identified to be a new species based on its molecular phylogeny and morphology. Molecular phylogenetic analysis revealed that the fungus belongs to a clade containing M. punicea and related species (M. punicea-related species) and that it forms a lineage independent of these species. Microscopic morphological comparisons with M. punicea-related species indicated that the new isolate differs with respect to the width of the phialides and length of the conidiophores. Comparison of macroscopic morphological characteristics revealed that M. punicea-related species are characterized by reddish-purple colonies, whereas the new isolate lacks this distinctive pigmentation. Moreover, the surface structure of the colonies of this fungus has a distinct irregular undulate pattern toward the margins. Given that this isolate can be clearly distinguished from the known M. punicea-related species, we consider the fungus to be a newly identified species, for which we propose the name Mariannaea imbricata sp. nov.

Draft Genome Sequence of Alternaria longipes Causing Tobacco Brown Spot

Alternaria is a cosmopolitan fungal genus associated with diverse hosts. Tobacco brown spot caused by Alternaria longipes is one of the most destructive diseases of tobacco. A. longipes can also infect many other plants, some animals and even humans. Here, we report a genome assembly of A. longipes CBS 540.94 using Oxford Nanopore Technologies. A total of 15 contigs were assembled, and the genome size was 37.5 Mb with contig N50 of 4.33 Mb. This genome resource will provide information for further research on comparative genomics of the genus Alternaria, and be a valuable resource in investigations of the molecular interactions of pathogen and hosts.

Bioactive metabolites of Cunninghamella, Biodiversity to Biotechnology

Cunninghamella is a fungal genus that belongs to family Cunninghamellaceae and has been involved as promising tool in many important mycotechnological applications. Cunninghamella is an endophytic fungus, their secondary metabolites are of potential biological activities especially as antimicrobial agents. The aim of this review is to highlight the description, ecology, and important in medicinal and industrial applications of the genus Cunninghamella in general. Moreover, describing the importance and potentials of this fungus in order to encourage for further studies to search, isolate, and purify already known metabolites. Also, screen for, and discover novel metabolites produced by this potent fungi in order to be involved in additional applications.

Allergen, pathogen, or biotechnological tool? The dematiaceous fungi Alternaria what’s for it and what’s on it?

Fungi are rich sources of biologically active natural compounds, which are used in the manufacturing of wide range of clinically important drugs. Alternaria is a fungal genus that belongs to family Pleosporaceae, and has been known as a promising secondary metabolites producer. However the same fungus showed harmful pathogenicity against different plants causing crops economical losses, and is a common allergen in humans, growing indoors and causing hay fever or hypersensitivity reactions. Alternaria is a multicultural fungal genus widely distributing in soil and organic matter. It includes saprophytic, endophytic and pathogenic species. This review aims to briefly summarize the structurally different metabolites produced by Alternaria fungi, as well as their occurrences, biological activities and functions.

Taxonomic Evaluation of a Bioherbicidal Isolate of Albifimbria verrucaria, Formerly Myrothecium verrucaria

The fungal genus Myrothecium was once polyphyletic but a recent reconsideration of the family Stachybotryaceae spilt it into several genera. The ex-neotype specimen of the species Myrothecium verrucaria is now recognized as Albifimbria verrucaria. The well-studied plant pathogen and candidate bioherbicide CABI-IMI 368023, previously identified as M. verrucaria, was analyzed morphologically and genetically and found to be most consistently aligned with the other representatives of A. verrucaria.

Microbial Associations with Pancreatic Cancer: A New Frontier in Biomarkers

Pancreatic cancer (PC) remains a global health concern with high mortality and is expected to increase as a proportion of overall cancer cases in the coming years. Most patients are diagnosed at a late stage of disease progression, which contributes to the extremely low 5-year survival rates. Presently, screening for PC remains costly and time consuming, precluding the use of widespread testing. Biomarkers have been explored as an option by which to ameliorate this situation. The authors conducted a search of available literature on PubMed to present the current state of understanding as it pertains to the use of microbial biomarkers and their associations with PC. Carriage of certain bacteria in the oral cavity (e.g., Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Streptococcus sp.), gut (e.g., Helicobacter pylori, Synergistetes, Proteobacteria), and pancreas (e.g., Fusobacterium sp., Enterobacteriaceae, Pseudomonadaceae) has been associated with an increased risk of developing PC. Additionally, the fungal genus Malassezia has likewise been associated with PC development. This review further outlines potential oncogenic mechanisms involved in the microbial-associated development of PC.