IMA Genome - F16 – Draft genome assemblies of Fusarium marasasianum, Huntiella abstrusa, two Immersiporthe knoxdaviesiana isolates, Macrophomina pseudophaseolina, Macrophomina phaseolina, Naganishia randhawae, and Pseudocercospora cruenta

Draft genome assembly of Fusarium marasasianum Introduction Many plants are thought to have at least one Fusarium-associated disease with more than 80% of economically important plants affected by at least one Fusarium disease (Leslie and Summerell 2006). The socioeconomic importance of Fusarium is particularly evident when considering the Fusarium fujikuroi species complex (FFSC, sensu Geiser et al. 2021). This monophyletic group contains 65 species and numerous cryptic species (Yilmaz et al. 2021). More than 50 species in the FFSC have publicly available genomes (www.ncbi.nlm.nih.gov), indicative of their economic importance. A number of recent studies showed that the FFSC complex contains four large clades (Herron et al. 2015; Sandoval-Denis et al. 2018; Yilmaz et al. 2021). One of these corresponds to the so-called “American” clade that was initially proposed to reflect the biogeography of the species it contains (O’Donnell et al. 1998). For example, Fusarium circinatum, the pine pitch canker pathogen, is thought to be native to Mexico and Central America (Drenkhan et al. 2020), where it likely co-evolved with its Pinus hosts (Herron et al. 2015; O’Donnell et al. 1998; Wikler and Gordon 2000). The American clade also includes five additional species associated with Pinus species in Colombia. These species are F. fracticaudum, F. pininemorale, F. parvisorum, F. marasasianum, and F. sororula, of which F. parvisorum, F. marasasianum, and F. sororula displayed levels of pathogenicity that were comparable to those of F. circinatum on susceptible Pinus species (Herron et al. 2015). The risk that the various American clade species pose to forestry in Colombia and globally has provided the impetus for projects aiming to sequence their genomes. To complement the genomic resources available for F. circinatum (Fulton et al. 2020; van der Nest et al. 2014a; Van Wyk et al. 2018; Wingfield et al. 2012, 2018a), the genomes of F. pininemorale (Wingfield et al. 2017), F. fracticaudum (Wingfield et al. 2018b) and F. sororula (van der Nest et al. 2021) have been published. Here we present the whole genome sequence for the pine pathogen F. marasasianum, named after the late South African professor Walter “Wally” F.O. Marasas (Wingfield and Crous 2012) who specialised in the taxonomy of Fusarium species and their associated mycotoxins

IMA Genome - F15: Draft genome assembly of Fusarium pilosicola, Meredithiella fracta, Niebla homalea, Pyrenophora teres hybrid WAC10721, and Teratosphaeria viscida

No abstract available.The Meredithiella fracta genome, the Galaxy server is in part funded by Collaborative Research Centre 992 Medical Epigenetics and German Federal Ministry of Education and Research. The Department of Science and Innovation (DSI)-National Research Foundation (NRF) Centre of Excellence in Plant Health Biotechnology (CPHB), South Africa and the DSTNRF SARChI chair in Fungal Genomics for the Fusarium pilosicola, Teratosphaeria viscida and Meredithiella fracta genomes.http://www.imafungus.orgam2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Draft genome sequence of Annulohypoxylon stygium, Aspergillus mulundensis, Berkeleyomyces basicola (syn. Thielaviopsis basicola), Ceratocystis smalleyi, two Cercospora beticola strains, Coleophoma cylindrospora, Fusarium fracticaudum, Phialophora cf. hyalina, and Morchella septimelata

Draft genomes of the species Annulohypoxylon stygium, Aspergillus mulundensis, Berkeleyomyces basicola (syn. Thielaviopsis basicola), Ceratocystis smalleyi, two Cercospora beticola strains, Coleophoma cylindrospora, Fusarium fracticaudum, Phialophora cf. hyalina and Morchella septimelata are presented. Both mating types (MAT1-1 and MAT1-2) of Cercospora beticola are included. Two strains of Coleophoma cylindrospora that produce sulfated homotyrosine echinocandin variants, FR209602, FR220897 and FR220899 are presented. The sequencing of Aspergillus mulundensis, Coleophoma cylindrospora and Phialophora cf. hyalina has enabled mapping of the gene clusters encoding the chemical diversity from the echinocandin pathways, providing data that reveals the complexity of secondary metabolism in these different species. Overall these genomes provide a valuable resource for understanding the molecular processes underlying pathogenicity (in some cases), biology and toxin production of these economically important fungi

It’s All in the Genes: The Regulatory Pathways of Sexual Reproduction in Filamentous Ascomycetes

Sexual reproduction in filamentous ascomycete fungi results in the production of highly specialized sexual tissues, which arise from relatively simple, vegetative mycelia. This conversion takes place after the recognition of and response to a variety of exogenous and endogenous cues, and relies on very strictly regulated gene, protein, and metabolite pathways. This makes studying sexual development in fungi an interesting tool in which to study gene−gene, gene−protein, and protein−metabolite interactions. This review provides an overview of some of the most important genes involved in this process; from those involved in the conversion of mycelia into sexually-competent tissue, to those involved in the development of the ascomata, the asci, and ultimately, the ascospores

Distribution and Evolution of Nonribosomal Peptide Synthetase Gene Clusters in the <i>Ceratocystidaceae</i>

In filamentous fungi, genes in secondary metabolite biosynthetic pathways are generally clustered. In the case of those pathways involved in nonribosomal peptide production, a nonribosomal peptide synthetase (NRPS) gene is commonly found as a main element of the cluster. Large multifunctional enzymes are encoded by members of this gene family that produce a broad spectrum of bioactive compounds. In this research, we applied genome-based identification of nonribosomal peptide biosynthetic gene clusters in the family Ceratocystidaceae. For this purpose, we used the whole genome sequences of species from the genera Ceratocystis, Davidsoniella, Thielaviopsis, Endoconidiophora, Bretziella, Huntiella, and Ambrosiella. To identify and characterize the clusters, different bioinformatics and phylogenetic approaches, as well as PCR-based methods were used. In all genomes studied, two highly conserved NRPS genes (one monomodular and one multimodular) were identified and their potential products were predicted to be siderophores. Expression analysis of two Huntiella species (H. moniliformis and H. omanensis) confirmed the accuracy of the annotations and proved that the genes in both clusters are expressed. Furthermore, a phylogenetic analysis showed that both NRPS genes of the Ceratocystidaceae formed distinct and well supported clades in their respective phylograms, where they grouped with other known NRPSs involved in siderophore production. Overall, these findings improve our understanding of the diversity and evolution of NRPS biosynthetic pathways in the family Ceratocystidaceae

Genes implicated in sexual reproduction in ascomycete fungi.

<p>Genes implicated in sexual reproduction in ascomycete fungi.</p

Pheromone expression reveals putative mechanism of unisexuality in a saprobic ascomycete fungus

<div><p>Homothallism (self-fertility) describes a wide variety of sexual strategies that enable a fungus to reproduce in the absence of a mating partner. Unisexual reproduction, a form of homothallism, is a process whereby a fungus can progress through sexual reproduction in the absence of mating genes previously considered essential for self-fertility. In this study, we consider the molecular mechanisms that allow for this unique sexual behaviour in the saprotrophic ascomycete; <i>Huntiella moniliformis</i>. These molecular mechanisms are also compared to the underlying mechanisms that control sex in <i>Huntiella omanensis</i>, a closely related, but self-sterile, species. The main finding was that <i>H</i>. <i>omanensis</i> displayed mating-type dependent expression of the <b>a</b>- and <b>α</b>-pheromones. This was in contrast to <i>H</i>. <i>moniliformis</i> where both pheromones were co-expressed during vegetative growth and sexual development. Furthermore, <i>H</i>. <i>moniliformis</i> also expressed the receptors of both pheromones. Consequently, this fungus is likely able to recognize and respond to the endogenously produced pheromones, allowing for self-fertility in the absence of other key mating genes. Overall, these results are concomitant with those reported for other unisexual species, but represent the first detailed study considering the unisexual behaviour of a filamentous fungus.</p></div

Genes expressed by vegetative and sexually reproducing isolate types of the two <i>Huntiella</i> species.

<p><b>A</b>: The <i>H</i>. <i>moniliformis</i> draft genome has 6 864 predicted ORFs and expressed 97% of these during the course of this study. <b>B</b>: Similarly, the <i>H</i>. <i>omanensis</i> draft genome has 8 394 predicted ORFs, 94% of which were expressed.</p

The proposed model for unisexual reproduction in <i>H</i>. <i>moniliformis</i> via the mating-type independent pheromone expression.

<p><b>A</b>: The pheromone system in <i>H</i>. <i>omanensis</i>: MAT1 individuals express the <b>α</b>-factor pheromone and MAT2 individuals express the <b>a</b>-factor pheromone (1). These pheromones are secreted (2) and recognized by the pheromone receptors of a suitable mating partner (3). This recognition activates the pheromone transduction pathway, a MAP kinase cascade (4). Assuming other sex-favouring environmental conditions are met, this cascade alters gene expression patterns within the cells (5) and allows for the conversion of vegetative mycelia into sexually-competent tissue (6). <b>B</b>: The proposed pheromone system in <i>H</i>. <i>moniliformis</i>. The two species systems likely work in a very similar manner, except that <i>H</i>. <i>moniliformis</i> is able to express, secrete and recognize both the <b>α</b>- and <b>a</b>-factor pheromones (1, 2 & 3). Once the MAP kinase cascade has been activated (4), the genetic and physiological changes are likely very similar to those in <i>H</i>. <i>omanensis</i> (5 & 6).</p