Ancient duplications, multidimensional specializations, and defense role of hexokinases in wheat.

Hexokinases (HXKs), which sense and catalyze cellular sugar, play a critical role in the growth and development of various plants, including wheat, a primary source of human calories frequently attacked by fungal pathogens. However, the evolutionary dynamics and functional diversification of HXKs in wheat, particularly their roles in plant defense, remain unclear. Here, we discovered that the wheat hexokinase gene family originated through multiple ancient gene duplications across different plant lineages and has undergone comprehensive, multidimensional functional specialization in gene expression, subcellular localization, enzyme activity, and regulation of plant defense responses.

Hyphal editing of the conserved premature stop codon in CHE1 is stimulated by oxidative stress in Fusarium graminearum.

Although genome-wide A-to-I editing mediated by adenosine-deaminase-acting-on-tRNA (ADAT) occurs during sexual reproduction in the presence of stage-specific cofactors, RNA editing is not known to occur during vegetative growth in filamentous fungi. Here we identified 33 A-to-I RNA editing events in vegetative hyphae of Fusarium graminearum and functionally characterized one conserved hyphal-editing site. Similar to ADAT-mediated editing during sexual reproduction, majority of hyphal-editing sites are in coding sequences and nonsynonymous, and have strong preference for U at -1 position and hairpin loops.

Functions and mechanisms of A-to-I RNA editing in filamentous ascomycetes.

Although lack of ADAR (adenosine deaminase acting on RNA) orthologs, genome-wide A-to-I editing occurs specifically during sexual reproduction in a number of filamentous ascomycetes, including Fusarium graminearum and Neurospora crassa. Unlike ADAR-mediated editing in animals, fungal A-to-I editing has a strong preference for hairpin loops and U at -1 position, which leads to frequent editing of UAG and UAA stop codons. Majority of RNA editing events in fungi are in the coding region and cause amino acid changes.

Regulation of TRI5 expression and deoxynivalenol biosynthesis by a long non-coding RNA in Fusarium graminearum.

Deoxynivalenol (DON) is the most frequently detected mycotoxin in cereal grains and processed food or feed. Two transcription factors, Tri6 and Tri10, are essential for DON biosynthesis in Fusarium graminearum. In this study we conduct stranded RNA-seq analysis with tri6 and tri10 mutants and show that Tri10 acts as a master regulator controlling the expression of sense and antisense transcripts of TRI6 and over 450 genes with diverse functions.

Adaptive advantages of restorative RNA editing in fungi for resolving survival-reproduction trade-offs.

RNA editing in various organisms commonly restores RNA sequences to their ancestral state, but its adaptive advantages are debated. In fungi, restorative editing corrects premature stop codons in pseudogenes specifically during sexual reproduction. We characterized 71 pseudogenes and their restorative editing in , demonstrating that restorative editing of 16 pseudogenes is crucial for germ tissue development in fruiting bodies.

Genome-Wide Informative Microsatellite Markers and Population Structure of from Argentina and the USA.

Soybean sudden death syndrome (SDS) is a destructive disease that causes substantial yield losses in South and North America. Whereas four species were identified as the causal agents, is the primary SDS-causing pathogen in North America and it also contributes substantially to SDS in Argentina. In this study, we comparatively analyzed genome assemblies of four strains and identified 29 informative microsatellite markers.

Regulation of symbiotic interactions and primitive lichen differentiation by UMP1 MAP kinase in Umbilicaria muhlenbergii.

Lichens are of great ecological importance but mechanisms regulating lichen symbiosis are not clear. Umbilicaria muhlenbergii is a lichen-forming fungus amenable to molecular manipulations and dimorphic. Here, we established conditions conducive to symbiotic interactions and lichen differentiation and showed the importance of UMP1 MAP kinase in lichen development.

A non-pheromone GPCR is essential for meiosis and ascosporogenesis in the wheat scab fungus.

Meiosis is essential for generating genetic diversity and sexual spores, but the regulation of meiosis and ascosporogenesis is not clear in filamentous fungi, in which dikaryotic and diploid cells formed inside fruiting bodies are not free living and independent of pheromones or pheromone receptors. In this study, Gia1, a non-pheromone GPCR (G protein-coupled receptor) with sexual-specific expression in , is found to be essential for ascosporogenesis. The mutant was normal in perithecium development, crozier formation, and karyogamy but failed to undergo meiosis, which could be partially rescued by a dominant active mutation in and activation of the Gpmk1 pathway.

Herbicide 2,4-dichlorophenoxyacetic acid interferes with MAP kinase signaling in Fusarium graminearum and is inhibitory to fungal growth and pathogenesis.

Plant hormones are important for regulating growth, development, and plant-pathogen interactions. Some of them are inhibitory to growth of fungal pathogens but the underlying mechanism is not clear. In this study, we found that hyphal growth of Fusarium graminearum was significantly reduced by high concentrations of IAA and its metabolically stable analogue 2,4-dichlorophenoxyacetic acid (2,4-D).

Experimental evidence for the functional importance and adaptive advantage of A-to-I RNA editing in fungi.

Adenosine-to-inosine (A-to-I) editing is the most prevalent type of RNA editing in animals, and it occurs in fungi specifically during sexual reproduction. However, it is debatable whether A-to-I RNA editing is adaptive. Deciphering the functional importance of individual editing sites is essential for the mechanistic understanding of the adaptive advantages of RNA editing.

FgSnt1 of the Set3 HDAC complex plays a key role in mediating the regulation of histone acetylation by the cAMP-PKA pathway in Fusarium graminearum.

The cAMP-PKA pathway is critical for regulating growth, differentiation, and pathogenesis in fungal pathogens. In Fusarium graminearum, mutants deleted of PKR regulatory-subunit of PKA had severe defects but often produced spontaneous suppressors. In this study eleven pkr suppressors were found to have mutations in FgSNT1, a component of the Set3C histone deacetylase (HDAC) complex, that result in the truncation of its C-terminal region.

Nitrogen repression of deoxynivalenol biosynthesis is mediated by Mep2 ammonium permease in Fusarium graminearum.

Fusarium graminearum is an important wheat pathogen and a producer of deoxynivalenol (DON). Biosynthesis of DON is suppressed by ammonium and induced by arginine and polyamines. To better understand ammonium repression of DON biosynthesis, in this study, we functionally characterized three ammonium permease (MEP) genes in F.

Uncovering -Regulatory Elements Important for A-to-I RNA Editing in Fusarium graminearum.

Adenosine-to-inosine (A-to-I) RNA editing independent of adenosine deaminase acting on RNA (ADAR) enzymes was discovered in fungi recently, and shown to be crucial for sexual reproduction. However, the underlying mechanism for editing is unknown. Here, we combine genome-wide comparisons, proof-of-concept experiments, and machine learning to decipher -regulatory elements of A-to-I editing in Fusarium graminearum.

Stage-Specific Genetic Interaction between and during Vegetative Growth and Conidiation in .

CK1 casein kinases are well conserved in filamentous fungi. However, their functions are not well characterized in plant pathogens. In , deletion of caused severe growth defects and loss of conidiation, fertility, and pathogenicity.

The Fng3 ING protein regulates H3 acetylation and H4 deacetylation by interacting with two distinct histone-modifying complexes.

The steady-state level of histone acetylation is maintained by histone acetyltransferase (HAT) and histone deacetylase (HDAC) complexes. INhibitor of Growth (ING) proteins are key components of the HAT or HDAC complexes but their relationship with other components and roles in phytopathogenic fungi are not well-characterized. Here, the FNG3 ING gene was functionally characterized in the wheat head blight fungus Fusarium graminearum.

Landscape and regulation of alternative splicing and alternative polyadenylation in a plant pathogenic fungus.

Alternative splicing (AS) and alternative polyadenylation (APA) contribute significantly to the regulation of gene expression in higher eukaryotes. Their biological impact in filamentous fungi, however, is largely unknown. Here we combine PacBio Isoform-Sequencing and strand-specific RNA-sequencing of multiple tissues and mutant characterization to reveal the landscape and regulation of AS and APA in Fusarium graminearum.

Deletion of all three MAP kinase genes results in severe defects in stress responses and pathogenesis in Fusarium graminearum.

Mitogen-activated protein kinase (MAPK) cascades are activated by external stimuli and convert signals to cellular changes. Individual MAPKs have been characterized in a number of plant pathogenic fungi for their roles in pathogenesis and responses to biotic or abiotic stresses. However, mutants deleted of all the MAPK genes have not been reported in filamentous fungi.

Elucidation of ustilaginoidin biosynthesis reveals a previously unrecognised class of ene-reductases.

Ustilaginoidins are a type of mycotoxin featuring a dimeric naphtho-γ-pyrone skeleton, produced by the rice false smut pathogen . Here we used gene disruption, heterologous expression in , feeding experiments, and experiments to fully elucidate the biosynthesis of ustilaginoidins. A new route to dimeric 2,3-unsaturated naphtho-γ-pyrones dimerization of YWA1 (and 3-methyl YWA1) followed by dehydration was discovered.

Regulation of biotic interactions and responses to abiotic stresses by MAP kinase pathways in plant pathogenic fungi.

Like other eukaryotes, fungi use MAP kinase (MAPK) pathways to mediate cellular changes responding to external stimuli. In the past two decades, three well-conserved MAP kinase pathways have been characterized in various plant pathogenic fungi for regulating responses and adaptations to a variety of biotic and abiotic stresses encountered during plant infection or survival in nature. The invasive growth (IG) pathway is homologous to the yeast pheromone response and filamentation pathways.