Biochemical and Mechanistic Characterization of the Fungal Reverse 1-Dimethylallyltryptophan Synthase DMATS1.

Dimethylallyltryptophan synthases catalyze the regiospecific transfer of (oligo)prenylpyrophosphates to aromatic substrates like tryptophan derivatives. These reactions are key steps in many biosynthetic pathways of fungal and bacterial secondary metabolites. investigations on recombinant DMATS1 from identified the enzyme as the first selective reverse tryptophan--1 prenyltransferase of fungal origin.

Production and Role of Hormones During Interaction of Species With Maize ( L.) Seedlings.

It has long been known that hormones affect the interaction of a phytopathogen with its host plant. The pathogen can cause changes in plant hormone homeostasis directly by affecting biosynthesis or metabolism in the plant or by synthesizing and secreting the hormone itself. We previously demonstrated that pathogenic fungi of the species complex are able to produce three major types of hormones: auxins, cytokinins, and gibberellins.

Set1 and Kdm5 are antagonists for H3K4 methylation and regulators of the major conidiation-specific transcription factor gene ABA1 in Fusarium fujikuroi.

Here we present the identification and characterization of the H3K4-specific histone methyltransferase Set1 and its counterpart, the Jumonji C demethylase Kdm5, in the rice pathogen Fusarium fujikuroi. While Set1 is responsible for all detectable H3K4me2/me3 in this fungus, Kdm5 antagonizes the H3K4me3 mark. Notably, deletion of both SET1 and KDM5 mainly resulted in the upregulation of genome-wide transcription, also affecting a large set of secondary metabolite (SM) key genes.

Secondary metabolism in Fusarium fujikuroi: strategies to unravel the function of biosynthetic pathways.

The fungus Fusarium fujikuroi causes bakanae disease of rice due to its ability to produce the plant hormones, the gibberellins. The fungus is also known for producing harmful mycotoxins (e.g.

Elucidation of the Two H3K36me3 Histone Methyltransferases Set2 and Ash1 in Unravels Their Different Chromosomal Targets and a Major Impact of Ash1 on Genome Stability.

In this work, we present a comprehensive analysis of the H3K36 histone methyltransferases Set2 and Ash1 in the filamentous ascomycete In , one single methyltransferase, Set2, confers all H3K36 methylation, while there are two members of the Set2 family in filamentous fungi, and even more H3K36 methyltransferases in higher eukaryotes. Whereas the yeast Set2 homolog has been analyzed in fungi previously, the second member of the Set2 family, designated Ash1, has not been described for any filamentous fungus. Western blot and ChIP-Seq analyses confirmed that Set2 and Ash1 are H3K36-specific histone methyltransferases that deposit H3K36me3 at specific loci: Set2 is most likely responsible for H3K36 methylation of euchromatic regions of the genome, while Ash1 methylates H3K36 at the subtelomeric regions (facultative heterochromatin) of all chromosomes, including the accessory chromosome XII.

Analysis of the global regulator Lae1 uncovers a connection between Lae1 and the histone acetyltransferase HAT1 in Fusarium fujikuroi.

The fungus Fusarium fujikuroi causes "bakanae" disease of rice due to its ability to produce gibberellins (GAs), a family of plant hormones. Recent genome sequencing revealed the genetic capacity for the biosynthesis of 46 additional secondary metabolites besides the industrially produced GAs. Among them are the pigments bikaverin and fusarubins, as well as mycotoxins, such as fumonisins, fusarin C, beauvericin, and fusaric acid.

Comparative genomics of geographically distant Fusarium fujikuroi isolates revealed two distinct pathotypes correlating with secondary metabolite profiles.

Fusarium fujikuroi causes bakanae ("foolish seedling") disease of rice which is characterized by hyper-elongation of seedlings resulting from production of gibberellic acids (GAs) by the fungus. This plant pathogen is also known for production of harmful mycotoxins, such as fusarins, fusaric acid, apicidin F and beauvericin. Recently, we generated the first de novo genome sequence of F.

The GATA-Type Transcription Factor Csm1 Regulates Conidiation and Secondary Metabolism in .

GATA-type transcription factors (TFs) such as the nitrogen regulators AreA and AreB, or the light-responsive TFs WC-1 and WC-2, play global roles in fungal growth and development. The conserved GATA TF NsdD is known as an activator of sexual development and key repressor of conidiation in , and as light-regulated repressor of macroconidia formation in In the present study, we functionally characterized the NsdD ortholog in , named Csm1. Deletion of this gene resulted in elevated microconidia formation in the wild-type (WT) and restoration of conidiation in the non-sporulating velvet mutant Δ demonstrating that Csm1 also plays a role as repressor of conidiation in .

Comparative transcriptome and proteome analysis reveals a global impact of the nitrogen regulators AreA and AreB on secondary metabolism in Fusarium fujikuroi.

The biosynthesis of multiple secondary metabolites in the phytopathogenic ascomycete Fusarium fujikuroi is strongly affected by nitrogen availability. Here, we present the first genome-wide transcriptome and proteome analysis that compared the wild type and deletion mutants of the two major nitrogen regulators AreA and AreB. We show that AreB acts not simply as an antagonist of AreA counteracting the expression of AreA target genes as suggested based on the yeast model.

Establishment of the Inducible Tet-On System for the Activation of the Silent Trichosetin Gene Cluster in Fusarium fujikuroi.

The PKS-NRPS-derived tetramic acid equisetin and its -desmethyl derivative trichosetin exhibit remarkable biological activities against a variety of organisms, including plants and bacteria, e.g., .

Nitrate Assimilation in Is Controlled by Multiple Levels of Regulation.

Secondary metabolite production of the phytopathogenic ascomycete fungus is greatly influenced by the availability of nitrogen. While favored nitrogen sources such as glutamine and ammonium are used preferentially, the uptake and utilization of nitrate is subject to a regulatory mechanism called nitrogen metabolite repression (NMR). In , the transcriptional control of the nitrate assimilatory system is carried out by the synergistic action of the nitrate-specific transcription factor NirA and the major nitrogen-responsive regulator AreA.

A Fungal N-Dimethylallyltryptophan Metabolite from Fusarium fujikuroi.

The range of secondary metabolites (SMs) produced by the rice pathogen Fusarium fujikuroi is quite broad. Several polyketides, nonribosomal peptides and terpenes have been identified. However, no products of dimethylallyltryptophan synthases (DMATSs) have been elucidated, although two putative DMATS genes are present in the F.

Lack of the COMPASS Component Ccl1 Reduces H3K4 Trimethylation Levels and Affects Transcription of Secondary Metabolite Genes in Two Plant-Pathogenic Species.

In the two fungal pathogens and , secondary metabolites (SMs) are fitness and virulence factors and there is compelling evidence that the coordination of SM gene expression is under epigenetic control. Here, we characterized Ccl1, a subunit of the COMPASS complex responsible for methylating lysine 4 of histone H3 (H3K4me). We show that Ccl1 is not essential for viability but a regulator of genome-wide trimethylation of H3K4 (H3K4me3).

Comparative "Omics" of the Fusarium fujikuroi Species Complex Highlights Differences in Genetic Potential and Metabolite Synthesis.

Species of the Fusarium fujikuroi species complex (FFC) cause a wide spectrum of often devastating diseases on diverse agricultural crops, including coffee, fig, mango, maize, rice, and sugarcane. Although species within the FFC are difficult to distinguish by morphology, and their genes often share 90% sequence similarity, they can differ in host plant specificity and life style. FFC species can also produce structurally diverse secondary metabolites (SMs), including the mycotoxins fumonisins, fusarins, fusaric acid, and beauvericin, and the phytohormones gibberellins, auxins, and cytokinins.

Gibepyrone Biosynthesis in the Rice Pathogen Fusarium fujikuroi Is Facilitated by a Small Polyketide Synthase Gene Cluster.

The 2H-pyran-2-one gibepyrone A and its oxidized derivatives gibepyrones B-F have been isolated from the rice pathogenic fungus Fusarium fujikuroi already more than 20 years ago. However, these products have not been linked to the respective biosynthetic genes, and therefore, their biosynthesis has not yet been analyzed on a molecular level. Feeding experiments with isotopically labeled precursors clearly supported a polyketide origin for the formal monoterpenoid gibepyrone A, whereas the terpenoid pathway could be excluded.

Sound of silence: the beauvericin cluster in Fusarium fujikuroi is controlled by cluster-specific and global regulators mediated by H3K27 modification.

In this study, we compared the secondary metabolite profile of Fusarium fujikuroi and the histone deacetylase mutant ΔHDA1. We identified a novel peak in ΔHDA1, which was identified as beauvericin (BEA). Going in line with a 1000-fold increased BEA production, the respective non-ribosomal peptide synthetase (NRPS)-encoding gene (BEA1), as well as two adjacent genes (BEA2-BEA3), were significantly up-regulated in ΔHDA1 compared to the wild type.

The SAGA complex in the rice pathogen Fusarium fujikuroi: structure and functional characterization.

Post-translational modification of histones is a crucial mode of transcriptional regulation in eukaryotes. A well-described acetylation modifier of certain lysine residues is the Spt-Ada-Gcn5 acetyltransferase (SAGA) complex assembled around the histone acetyltransferase Gcn5 in Saccharomyces cerevisiae. We identified and characterized the SAGA complex in the rice pathogen Fusarium fujikuroi, well-known for producing a large variety of secondary metabolites (SMs).

Knock-down of the methyltransferase Kmt6 relieves H3K27me3 and results in induction of cryptic and otherwise silent secondary metabolite gene clusters in Fusarium fujikuroi.

Filamentous fungi produce a vast array of secondary metabolites (SMs) and some play a role in agriculture or pharmacology. Sequencing of the rice pathogen Fusarium fujikuroi revealed the presence of far more SM-encoding genes than known products. SM production is energy-consuming and thus tightly regulated, leaving the majority of SM gene clusters silent under laboratory conditions.

Mechanistic Characterisation of Two Sesquiterpene Cyclases from the Plant Pathogenic Fungus Fusarium fujikuroi.

Two sesquiterpene cyclases from Fusarium fujikuroi were expressed in Escherichia coli and purified. The first enzyme was inactive because of a critical mutation, but activity was restored by sequence correction through site-directed mutagenesis. The mutated enzyme and two naturally functional homologues from other fusaria converted farnesyl diphosphate into guaia-6,10(14)-diene.

Interplay between pathway-specific and global regulation of the fumonisin gene cluster in the rice pathogen Fusarium fujikuroi.

The rice pathogenic fungus Fusarium fujikuroi is known to produce a large variety of secondary metabolites. Besides the gibberellins, causing the bakanae effect in infected rice seedlings, the fungus produces several mycotoxins and pigments. Among the 47 putative secondary metabolite gene clusters identified in the genome of F.

Two separate key enzymes and two pathway-specific transcription factors are involved in fusaric acid biosynthesis in Fusarium fujikuroi.

Fusaric acid (FSA) is a mycotoxin produced by several fusaria, including the rice pathogen Fusarium fujikuroi. Genes involved in FSA biosynthesis were previously identified as a cluster containing a polyketide synthase (PKS)-encoding (FUB1) and four additional genes (FUB2-FUB5). However, the biosynthetic steps leading to FSA as well as the origin of the nitrogen atom, which is incorporated into the polyketide backbone, remained unknown.

Genetic engineering, high resolution mass spectrometry and nuclear magnetic resonance spectroscopy elucidate the bikaverin biosynthetic pathway in Fusarium fujikuroi.

Secondary metabolites of filamentous fungi can be highly bioactive, ranging from antibiotic to cancerogenic properties. In this study we were able to identify a new, yet unknown metabolite produced by Fusarium fujikuroi, an ascomycetous rice pathogen. With the help of genomic engineering and high-performance liquid chromatography (HPLC) coupled to high resolution mass spectrometry (HRMS) followed by isolation and detailed structure elucidation, the new substance could be designated as an unknown bikaverin precursor, missing two methyl- and one hydroxy group, hence named oxo-pre-bikaverin.

Isolation and Structure Elucidation of Fujikurins A-D: Products of the PKS19 Gene Cluster in Fusarium fujikuroi.

Fusarium fujikuroi is a member of the Gibberella fujikuroi species complex and well known for the production of gibberellins and mycotoxins including fusarins and fusaric acid. A recent genome sequencing study revealed that the fungus has the genetic potential to produce many more secondary metabolites than have been reported. This paper describes the structure elucidation of the products of the cryptic and silent PKS19 gene cluster that were recently identified (fujikurins A-D).

The General Amino Acid Permease FfGap1 of Fusarium fujikuroi Is Sorted to the Vacuole in a Nitrogen-Dependent, but Npr1 Kinase-Independent Manner.

The rice pathogenic fungus Fusarium fujikuroi is well known for the production of a broad spectrum of secondary metabolites (SMs) such as gibberellic acids (GAs), mycotoxins and pigments. The biosynthesis of most of these SMs strictly depends on nitrogen availability and of the activity of permeases of nitrogen sources, e.g.

The VELVET Complex in the Gray Mold Fungus Botrytis cinerea: Impact of BcLAE1 on Differentiation, Secondary Metabolism, and Virulence.

Botrytis cinerea, the gray mold fungus, is an important plant pathogen. Field populations are characterized by variability with regard to morphology, the mode of reproduction (conidiation or sclerotia formation), the spectrum of secondary metabolites (SM), and virulence. Natural variation in bcvel1 encoding the ortholog of Aspergillus nidulans VeA, a member of the VELVET complex, was previously shown to affect light-dependent differentiation, the formation of oxalic acid (OA), and virulence.