Transmission ratio distortion in an interspecific cross between Fusarium circinatum and Fusarium subglutinans

Previously, an interspecific cross between Fusarium circinatum and Fusarium subglutinans was used to generate a genetic linkage map. A ca. 55 % of genotyped markers displayed transmission ratio distortion (TRD) that demonstrated a genome-wide distribution. The working hypothesis for this study was that TRD would be non-randomly distributed throughout the genetic linkage map. This would indicate the presence of distorting loci. Using a genome-wide threshold of α = 0.01, 79 markers displaying TRD were distributed on all 12 linkage groups (LGs). Eleven putative transmission ratio distortion loci (TRDLs), spanning eight LGs, were identified in regions containing three or more adjacent markers displaying distortion. No epistatic interactions were observed between these TRDLs. Thus, it is uncertain whether the genome-wide TRD was due to linkage between markers and genomic regions causing distortion. The parental origins of markers followed a non-random distribution throughout the linkage map, with LGs containing stretches of markers originating from only one parent. Thus, due to the nature of the interspecific cross, the current hypothesis to explain these observations is that the observed genome-wide segregation was caused by the high level of genomic divergence between the parental isolates. Therefore, homologous chromosomes do not align properly during meiosis, resulting in aberrant transmission of markers. This also explains previous observations of the preferential transmission of F. subglutinans alleles to the F1 progenyThe National Research Foundation (NRF), University of Pretoria, Forestry and Agricultural Biotechnology Institute (FABI), the DST/NRF Center of Excellence in Tree Health Biotechnology (CTHB), members of the Tree Protection Co-operative Programme (TPCP), and the Andrew Mellon Foundation.http://link.springer.com/journal/13258hb201

QTL mapping of mycelial growth and aggressiveness to distinct hosts in Ceratocystis pathogens

Some species of Ceratocystis display strong host specificity, such as C. fimbriata sensu stricto that is restricted to sweet potato (Ipomoea batatas) as host. In contrast, the closely related C. manginecans, infects Acacia mangium and Mangifera indica but is not pathogenic to I. batatas. Despite the economic importance of these fungi, knowledge regarding the genetic factors that influence their pathogenicity and host specificity is limited. A recent inheritance study, based on an interspecific cross between C. fimbriata and C. manginecans and the resultant 70 F1 progeny, confirmed that traits such as mycelial growth rate, spore production and aggressiveness on A. mangium and I. batatas are regulated by multiple genes. In the present study, a quantitative trait locus (QTL) analysis was performed to determine the genomic loci associated with these traits. All 70 progeny isolates were genotyped with SNP markers and a linkage map was constructed. The map contained 467 SNPs, distributed across nine linkage groups, with a total length of 1203 cm. Using the progeny genotypes and phenotypes, one QTL was identified on the linkage map for mycelial growth rate, one for aggressiveness to A. mangium and two for aggressiveness to I. batatas (P < 0.05). Two candidate genes, likely associated with mycelial growth rate, were identified in the QTL region. The three QTLs associated with aggressiveness to different hosts contained candidate genes involved in protein processing, detoxification and regions with effector genes and high transposable element density. The results provide a foundation for studies considering the function of genes regulating various quantitative traits in Ceratocystis.Members of the Tree Protection Cooperative Programme, based at the Forestry and Agricultural Biotechnology Institute, and the Genomics Research Institute at the University of Pretoria, as well as the National Research Foundation, South Africa (Grant UID: 89619 and 95875) and the DST/NRF SARChI chair in Fungal Genomics.http://www.elsevier.com/locate/yfgbi2020-10-01hj2020BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Characterization of host-specific genes from pine- and grass-associated species of the Fusarium fujikuroi species complex

SUPPLEMENTARY MATERIALS : FIGURE S1. Phylogenetic relationship of paralogs with regards to the respective host-range-associated gene. FCIR = Fusarium circinatum; FFRAC = Fusarium fracticaudum; FPIN = Fusarium pininemorale; FSUB = Fusarium subglutinans; FIGURE S2. Host-range-associated genes with ancestral origins that emerged within the FFSC. The investigated host-range-associated genes are highlighted in yellow; FCIR = Fusarium circinatum and FTEMP = Fusarium temperatum; FIGURE S3. Host-range-associated genes with ancestral origins that emerged within the FFSC and FOSC. The investigated host-range-associated genes are highlighted in yellow; FCIR = Fusarium circinatum and FTEMP = Fusarium temperatum; FIGURE S4. Host-range-associated genes with ancestral origins that emerged within the broader Fusarium outside the FFSC and FOSC. The investigated host-range associated genes are highlighted in yellow; FCIR = Fusarium circinatum and FTEMP = Fusarium temperatum; FIGURE S5. Host-range-associated genes with less than 10 ancestral origin hits and mostly Fusarium. The investigated host-range-associated genes are highlighted in yellow; FCIR = Fusarium circinatum and FTEMP = Fusarium temperatum; FIGURE S6. Host-range-associated genes with ancestral origins hits and mostly not Fusarium. The investigated host-range-associated genes are highlighted in yellow; FCIR = Fusarium circinatum and FTEMP = Fusarium temperatum; FIGURE S7. Host-range-associated genes with ancestral origins outside Fusarium but in the Ascomycetes. The investigated host-range-associated genes are highlighted in yellow; FCIR = Fusarium circinatum and FTEMP = Fusarium temperatum; FIGURE S8. Host-range-associated genes with ancestral origins outside Fungi. The investigated host-range-associated genes are highlighted in yellow; FCIR = Fusarium circinatum and FTEMP = Fusarium temperatum; FIGURE S9. The distribution of host-range-associated genes from pine-host-associated Fusarium species and conservation of synteny across and between chromosomes and genomes. Pine-host-associated genes distribution across each of the chromosomes as indicated by the blue lines. The conservation of synteny and inversion between the relevant genomes are indicated in the brown blocks and red lines. FCIR = F. circinatum; chromosome size is given in kbp; FIGURE S10. The distribution of hostrange- associated genes from Poaceae-host-associated Fusarium species and conservation of synteny across and between chromosomes and genomes. Poaceae-host-associated gene distribution across each of the chromosomes as indicated by the blue lines. The conservation of synteny and inversion between the relevant genomes are indicated in the brown blocks and red lines. FTEMP = F. temperatum; chromosome size is given in kbp; FIGURE S11. The syntenous relationship between genes from F. circinatum versus F. temperatum; FIGURE S12. The syntenous relationship between genes from F. temperatum and F. circinatum; TABLE S1. BUSCO results for the relevant Fusarium genomes; TABLE S2. The size difference between the chromosomes of four of the six Fusarium species; TABLE S3. Presence of telomeres at chromosomal ends for the two representative Fusarium species examined; TABLE S4. The Blast2GO data for the 72 unique pine-host-associated genes specifically for (A) Fusarium circinatum, (B) F. fracticaudum and (C) F. pininemorale; TABLE S5. The Blast2GO data for the 47 unique Poaceae-host-associated genes, specifically for (A) Fusarium konzum, (B) F. subglutinans and (C) F. temperatum; TABLE S6. The Fischer exact test data for (A) the 72 unique pine-host-associated genes and (B) the 47 unique Poaceae-host-associated genes; TABLE S7. The EST and RNA-seq data for F. circinatum, obtained from Wingfield et al. [52] and Phasha et al. [53], respectively; TABLE S8. The placement of host-range-associated genes in groups that infer their evolutionary origins; TABLE S9. The gene information for the unique F. circinatum genes, in terms of chromosome location, subtelomeric placement, ancestral origin and BLAST description; TABLE S10. The gene information for the unique F. temperatum genes, in terms of chromosome location, subtelomeric placement, ancestral origin and BLAST description; TABLE S11. The host-range-associated gene density for both F. circinatum and F. temperatum; TABLE S12. The SynChro data for genes downstream and upstream of the host-rangeassociated genes of both the pine- and Poaceae-host-associated Fusarium species; FCIR = Fusarium circinatum and FTEMP = Fusarium temperatum.The Fusarium fujikuroi species complex (FFSC) includes socioeconomically important pathogens that cause disease for numerous crops and synthesize a variety of secondary metabolites that can contaminate feedstocks and food. Here, we used comparative genomics to elucidate processes underlying the ability of pine-associated and grass-associated FFSC species to colonize tissues of their respective plant hosts. We characterized the identity, possible functions, evolutionary origins, and chromosomal positions of the host-range-associated genes encoded by the two groups of fungi. The 72 and 47 genes identified as unique to the respective genome groups were potentially involved in diverse processes, ranging from transcription, regulation, and substrate transport through to virulence/pathogenicity. Most genes arose early during the evolution of Fusarium/FFSC and were only subsequently retained in some lineages, while some had origins outside Fusarium. Although differences in the densities of these genes were especially noticeable on the conditionally dispensable chromosome of F. temperatum (representing the grass-associates) and F. circinatum (representing the pine-associates), the host-range-associated genes tended to be located towards the subtelomeric regions of chromosomes. Taken together, these results demonstrate that multiple mechanisms drive the emergence of genes in the grass- and pine-associated FFSC taxa examined. It also highlighted the diversity of the molecular processes potentially underlying niche-specificity in these and other Fusarium species.The South African Department of Science and Innovation’s South African Research Chair Initiative, the DSI-NRF Centre of Excellence in Plant Health Biotechnology at the Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, the Food Safety National Program at the United States Department of Agriculture, Agricultural Research Service.https://www.mdpi.com/journal/pathogensam2023BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Intra-species genomic variation in the pine pathogen Fusarium circinatum

Fusarium circinatum is an important global pathogen of pine trees. Genome plasticity has been observed in different isolates of the fungus, but no genome comparisons are available. To address this gap, we sequenced and assembled to chromosome level five isolates of F. circinatum. These genomes were analysed together with previously published genomes of F. circinatum isolates, FSP34 and KS17. Multi-sample variant calling identified a total of 461,683 micro variants (SNPs and small indels) and a total of 1828 macro structural variants of which 1717 were copy number variants and 111 were inversions. The variant density was higher on the sub-telomeric regions of chromosomes. Variant annotation revealed that genes involved in transcription, transport, metabolism and transmembrane proteins were overrepresented in gene sets that were affected by high impact variants. A core genome representing genomic elements that were conserved in all the isolates and a non-redundant pangenome representing all genomic elements is presented. Whole genome alignments showed that an average of 93% of the genomic elements were present in all isolates. The results of this study reveal that some genomic elements are not conserved within the isolates and some variants are high impact. The described genome-scale variations will help to inform novel disease management strategies against the pathogen.DATA AVAILABILTY STATEMENT : The Whole Genome Shotgun project for Fusarium circinatum CMWF1803 has been deposited at DDBJ/ENA/GenBank under the accession JAEHFH000000000. The version described in this paper is version JAEHFH010000000. The Whole Genome Shotgun project for Fusarium circinatum CMWF560 has been deposited at DDBJ/ENA/GenBank under the accession JAEHFI000000000. The version described in this paper is version JAEHFI010000000. The Whole Genome Shotgun project for Fusarium circinatum CMWF567 has been deposited at DDBJ/ENA/GenBank under the accession JADZLS000000000. The version described in this paper is version JADZLS010000000. The Whole Genome Shotgun project for Fusarium circinatum UG27 has been deposited at DDBJ/ENA/ GenBank under the accession JAELVK000000000. The version described in this paper is version JAELVK010000000. The Whole Genome Shotgun project for Fusarium circinatum UG10 has been deposited at DDBJ/ENA/GenBank under the accession JAGJRQ000000000. The version described in this paper is version JAGJRQ010000000.The South African Department of Science and Innovation’s South African Research Chair Initiative and the DSI-NRF Centre of Excellence in Plant Health Biotechnology at the Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria.http://www.mdpi.com/journal/jofBiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Identification and characterization of a QTL for growth of Fusarium circinatum on pine-based medium

SUPPLEMENTARY FILE S1: HPLC and GC-MS results showing the broad overview and primary metabolites identified in the pine-based media. SUPPLEMENTARY FILE S2: The primer sequences and PCR protocols used to amplify gene regions in this study. SUPPLEMENTARY FILE S3: Reference mapping of F. circinatum Illumina and MinIon raw reads mapped to the genomes of F circinatum KS17 and F. temperatum. SUPPLEMENTARY FILE S4: Genic information of the identified genes and indel region in the QTL region of F. circinatum. InterProScan and gene ontology information are provided for all genes in this region. Further information on the retrotransposons and repeats that are characteristic of the indel within the QTL region is provided.Fusarium circinatum is an economically important pathogen of pine and resides in the Fusarium fujikuroi species complex. Here we investigated the molecular processes underlying growth in F. circinatum by exploring the association between growth and the nutritional environment provided by the pine host. For this purpose, we subjected a mapping population consisting of F. circinatum X F. temperatum hybrid progeny to an analysis of growth rate on a pine-tissue derived medium. These data, together with the available genetic linkage map for F. circinatum, were then used to identify Quantitative Trait Loci (QTLs) associated with growth. The single significant QTL identified was then characterized using the available genome sequences for the hybrid progeny’s parental isolates. This revealed that the QTL localized to two non-homologous regions in the F. circinatum and F. temperatum genomes. For one of these, the F. circinatum parent contained a two-gene deletion relative to the F. temperatum parent. For the other region, the two parental isolates encoded different protein products. Analysis of repeats, G+C content, and repeat-induced point (RIP) mutations further suggested a retrotransposon origin for the two-gene deletion in F. circinatum. Nevertheless, subsequent genome and PCR-based analyses showed that both regions were similarly polymorphic within a collection of diverse F. circinatum. However, we observed no clear correlation between the respective polymorphism patterns and growth rate in culture. These findings support the notion that growth is a complex multilocus trait and raise the possibility that the identified QTL contains multiple small-effect QTLs, of which some might be dependent on the genetic backgrounds. This study improved our current knowledge of the genetic determinants of vegetative growth in F. circinatum and provided an important foundation for determining the genes and processes underpinning its ability to colonize its host environment.The South African Department of Science and Innovation’s South African Research Chair Initiative and the DSI-NRF Centre of Excellence in Plant Health Biotechnology at the Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria.https://www.mdpi.com/journal/jofam2023BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyZoology and Entomolog

Genome-wide macrosynteny among Fusarium species in the Gibberella fujikuroi complex revealed by amplified fragment length polymorphisms

The Gibberella fujikuroi complex includes many Fusarium species that cause significant losses in yield and quality of agricultural and forestry crops. Due to their economic importance, whole-genome sequence information has rapidly become available for species including Fusarium circinatum, Fusarium fujikuroi and Fusarium verticillioides, each of which represent one of the three main clades known in this complex. However, no previous studies have explored the genomic commonalities and differences among these fungi. In this study, a previously completed genetic linkage map for an interspecific cross between Fusarium temperatum and F. circinatum, together with genomic sequence data, was utilized to consider the level of synteny between the three Fusarium genomes. Regions that are homologous amongst the Fusarium genomes examined were identified using in silico and pyrosequenced amplified fragment length polymorphism (AFLP) fragment analyses. Homology was determined using BLAST analysis of the sequences, with 777 homologous regions aligned to F. fujikuroi and F. verticillioides. This also made it possible to assign the linkage groups from the interspecific cross to their corresponding chromosomes in F. verticillioides and F. fujikuroi, as well as to assign two previously unmapped supercontigs of F. verticillioides to probable chromosomal locations. We further found evidence of a reciprocal translocation between the distal ends of chromosome 8 and 11, which apparently originated before the divergence of F. circinatum and F. temperatum. Overall, a remarkable level of macrosynteny was observed among the three Fusarium genomes, when comparing AFLP fragments. This study not only demonstrates how in silico AFLPs can aid in the integration of a genetic linkage map to the physical genome, but it also highlights the benefits of using this tool to study genomic synteny and architecture.National Research Foundation of South Africahttp://www.plosone.orgtm201

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

Draft genome sequences of Diplodia sapinea, Ceratocystis manginecans, and Ceratocystis moniliformis

The draft nuclear genomes of Diplodia sapinea, Ceratocystis moniliformis s. str., and C. manginecans are presented. Diplodia sapinea is an important shoot-blight and canker pathogen of Pinus spp., C. moniliformis is a saprobe associated with wounds on a wide range of woody angiosperms and C. manginecans is a serious wilt pathogen of mango and Acacia mangium. The genome size of D. sapinea is estimated at 36.97 Mb and contains 13 020 predicted genes. Ceratocystis moniliformis includes 25.43 Mb and is predicted to encode at least 6 832 genes. This is smaller than that reported for the mango wilt pathogen C. manginecans which is 31.71 Mb and is predicted to encode at least 7 494 genes. The latter is thus more similar to C. fimbriata s.str., the type species of the genus. The genome sequences presented here provide an important resource to resolve issues pertaining to the taxonomy, biology and evolution of these fungi.The University of Pretoria, the Department of Science and Technology (DST)/National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology, Genomics Research Institute (University of Pretoria) and Claude Leon Foundation, South Africa.http://www.imafungus.org/am201

Draft genomes of Amanita jacksonii, Ceratocystis albifundus, Fusarium circinatum, Huntiella omanensis, Leptographium procerum, Rutstroemia sydowiana, and Sclerotinia echinophila

The genomes of fungi provide an important resource to resolve issues pertaining to their taxonomy, biology, and evolution. The genomes of Amanita jacksonii, Ceratocystis albifundus, a Fusarium circinatum variant, Huntiella omanensis, Leptographium procerum, Sclerotinia echinophila, and Rutstroemia sydowiana are presented in this genome announcement. These seven genomes are from a number of fungal pathogens and economically important species. The genome sizes range from 27 Mb in the case of Ceratocystis albifundus to 51.9 Mb for Rutstroemia sydowiana. The latter also encodes for a predicted 17 350 genes, more than double that of Ceratocystis albifundus. These genomes will add to the growing body of knowledge of these fungi and provide a value resource to researchers studying these fungi.The US Department of Agriculture (USDA) Agricultural Research Service, grants from the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Royal Ontario Museum to J.M.M.; Graduate Scholarships from the Consejo Nacional de Ciencia y Tecnologia (Mexico) and the University of Toronto to SSR; and a Undergraduate Student Research Award from NSERC to M.S. Financial support was provided by members of the Tree Protection Cooperative Program (TPCP), the Department of Science and Technology (DST)/ National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology, and the Genomics Research Institute of the University of Pretoria. This project was supported by multiple grants from the NRF, South Africa, including the grant specific unique reference number (UID) 83924.http://www.imafungus.orgam201

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 assemblies of Fusarium marasasianum, Huntiella abstrusa, two Immersiporthe knoxdaviesiana isolates, Macrophomina pseudophaseolina, Macrophomina phaseolina, Naganishia randhawae, and Pseudocercospora cruenta.Department of Science and Technology (DSI) , South Africa National Research Foundation (NRF) , South Africa Centre of Excellence in Tree Health Biotechnology, South Africa.https://imafungus.biomedcentral.comBiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog