Martijn Rep
University of Amsterdam, Molecular Plant Pathology, Faculty Member
ObjectiveWilt caused byFusarium oxysporumf. sp.melonis(Fom) is one of the most widespread and destructive melon diseases worldwide. Whole-genome sequencing data of a diverse set of Fom strains, as well as several non-pathogenic strains... more
ObjectiveWilt caused byFusarium oxysporumf. sp.melonis(Fom) is one of the most widespread and destructive melon diseases worldwide. Whole-genome sequencing data of a diverse set of Fom strains, as well as several non-pathogenic strains isolated from melon from different parts of the world are described here. These data shed light on the genetic diversity, population structure and the potential evolutionary trajectories which have led to the emergence of different Fom races, and will facilitate identification of avirulence genes which will be helpful to develop resistant melon cultivars.Data descriptionGenomic DNA was extracted from mycelium of 38Fusarium oxysporum(Fo) strains collected from different parts of the world including Belgium, China, France, Iran, Israel, Japan, Mexico, New Zealand, Spain, the Netherlands, and the United States. The genomes were sequenced to ≈ 20 × coverage using the Illumina Hiseq Xten system, resulting in paired-end reads of 151 bp and assemblies of 167...
Research Interests:
Fusarium oxysoporum f. sp. radicis‐cucumerinum (Forc) is able to cause disease in cucumber, melon, and watermelon, while F. oxysporum f. sp. melonis (Fom) can only infect melon plants. Earlier research showed that mobile chromosomes in... more
Fusarium oxysoporum f. sp. radicis‐cucumerinum (Forc) is able to cause disease in cucumber, melon, and watermelon, while F. oxysporum f. sp. melonis (Fom) can only infect melon plants. Earlier research showed that mobile chromosomes in Forc and Fom determine the difference in host range between Forc and Fom. By closely comparing these pathogenicity chromosomes combined with RNA‐sequencing data, we selected 11 candidate genes that we tested for involvement in the difference in host range between Forc and Fom. One of these candidates is a putative effector gene on the Fom pathogenicity chromosome that has nonidentical homologs on the Forc pathogenicity chromosome. Four independent Forc transformants with this gene from Fom showed strongly reduced or no pathogenicity towards cucumber, while retaining pathogenicity towards melon and watermelon. This suggests that the protein encoded by this gene is recognized by an immune receptor in cucumber plants. This is the first time that a single...
Research Interests:
SummaryIn Fusarium oxysporum f.sp. lycopersici, all effector genes reported so far – also called SIX genes – are located on a single accessory chromosome which is required for pathogenicity and can also be horizontally transferred to... more
SummaryIn Fusarium oxysporum f.sp. lycopersici, all effector genes reported so far – also called SIX genes – are located on a single accessory chromosome which is required for pathogenicity and can also be horizontally transferred to another strain. To narrow down the minimal region required for virulence, we selected partial pathogenicity chromosome deletion strains by fluorescence‐assisted cell sorting of a strain in which the two arms of the pathogenicity chromosome were labelled with GFP and RFP respectively. By testing the virulence of these deletion mutants, we show that the complete long arm and part of the short arm of the pathogenicity chromosome are not required for virulence. In addition, we demonstrate that smaller versions of the pathogenicity chromosome can also be transferred to a non‐pathogenic strain and they are sufficient to turn the non‐pathogen into a pathogen. Surprisingly, originally non‐pathogenic strains that had received a smaller version of the pathogenici...
Research Interests:
Fusarium oxysporum f. sp. radicis‐cucumerinum (Forc) causes severe root rot and wilt in several cucurbit species, including cucumber, melon, and watermelon. Previously, a pathogenicity chromosome, chrRC, was identified in Forc. Strains... more
Fusarium oxysporum f. sp. radicis‐cucumerinum (Forc) causes severe root rot and wilt in several cucurbit species, including cucumber, melon, and watermelon. Previously, a pathogenicity chromosome, chrRC, was identified in Forc. Strains that were previously nonpathogenic could infect multiple cucurbit species after obtaining this chromosome via horizontal chromosome transfer (HCT). In contrast, F. oxysporum f. sp. melonis (Fom) can only cause disease on melon plants, even though Fom contains contigs that are largely syntenic with chrRC. The aim of this study was to identify the genetic basis underlying the difference in host range between Fom and Forc. First, colonization of different cucurbit species between Forc and Fom strains showed that although Fom did not reach the upper part of cucumber or watermelon plants, it did enter the root xylem. Second, to select candidate genomic regions associated with differences in host range, high‐quality genome assemblies of Fom001, Fom005, and ...
Research Interests:
During host colonization, plant pathogenic fungi secrete proteins, called effectors, to facilitate infection. Collectively, effectors may defeat the plant immune system, but usually not all effectors are equally important for infecting a... more
During host colonization, plant pathogenic fungi secrete proteins, called effectors, to facilitate infection. Collectively, effectors may defeat the plant immune system, but usually not all effectors are equally important for infecting a particular host plant. InFusarium oxysporumf.sp.lycopersici, all known effector genes – also calledSIXgenes – are located on a single accessory chromosome which is required for pathogenicity and can also be horizontally transferred to another strain. To narrow down the minimal region required for virulence, we selected partial pathogenicity chromosome deletion strains by fluorescence-assisted cell sorting of a strain in which the two arms of the pathogenicity chromosome were labelled withGFPandRFP, respectively. By testing the virulence of these deletion mutants, we show that the complete long arm and part of the short arm of the pathogenicity chromosome are not required for virulence. In addition, we demonstrate that smaller versions of the pathoge...
Research Interests:
The fungus Fusarium oxysporum f.sp. cubense (Focub) causes Fusarium wilt of banana. Focub strains are divided into races according to their host specificity, but which virulence factors underlie these interactions is currently unknown. In... more
The fungus Fusarium oxysporum f.sp. cubense (Focub) causes Fusarium wilt of banana. Focub strains are divided into races according to their host specificity, but which virulence factors underlie these interactions is currently unknown. In the F. oxysporum f.sp. lycopersici (Fol)-tomato system, small secreted fungal proteins, called Six proteins, were identified in the xylem sap of infected plants. The Fol Six1 protein contributes to virulence and has an avirulence function by activating the I-3 immune receptor of tomato. The Focub tropical race 4 (TR4) genome harbors three SIX1 homologs: SIX1a, b and c. In this study, the role of Focub-SIX1a in pathogenicity was evaluated since this homolog is present in not only TR4 but also in other races. A deletion mutant of the SIX1a gene from Focub TR4 strain II5 was generated (FocubΔSIX1a) and tested in planta. Mutants were found to be severely compromised in their virulence. Ectopic integration of the Focub-SIX1a gene in the FocubΔSIX1a stra...
Research Interests:
The polyphyletic nature of many formae speciales of Fusarium oxysporum (Fo) prevents molecular identification of newly encountered strains based on conserved, vertically inherited genes. Alternative molecular detection methods that could... more
The polyphyletic nature of many formae speciales of Fusarium oxysporum (Fo) prevents molecular identification of newly encountered strains based on conserved, vertically inherited genes. Alternative molecular detection methods that could replace labour- and time-intensive disease assays are therefore highly desired. Effectors are functional elements in the pathogen-host interaction and have been found to show very limited sequence diversity between strains of the same forma specialis, which makes them potential markers for host-specific pathogenicty. We therefore compared candidate effector genes extracted from 60 existing and 22 newly generated genome assemblies, specifically targeting strains affecting cucurbit plant species. Based on these candidate effector genes, in total eighteen PCR primer pairs were designed to discriminate between each of the seven Cucurbitaceae-affecting formae speciales. When tested on a collection of strains encompassing different clonal lineages of thes...
Research Interests:
Proteins secreted by pathogens during host colonization largely determine the outcome of pathogen-host interactions and are commonly called 'effectors'. In fungal plant pathogens, coordinated transcriptional up-regulation of... more
Proteins secreted by pathogens during host colonization largely determine the outcome of pathogen-host interactions and are commonly called 'effectors'. In fungal plant pathogens, coordinated transcriptional up-regulation of effector genes is a key feature of pathogenesis and effectors are often encoded in genomic regions with distinct repeat content, histone code and rate of evolution. In the tomato pathogen Fusarium oxysporum f. sp. lycopersici (Fol), effector genes reside on one of four accessory chromosomes, known as the 'pathogenicity' chromosome, which can be exchanged between strains through horizontal transfer. The three other accessory chromosomes in the Fol reference strain may also be important for virulence towards tomato. Expression of effector genes in Fol is highly up-regulated upon infection and requires Sge1, a transcription factor encoded on the core genome. Interestingly, the pathogenicity chromosome itself contains 13 predicted transcription facto...
Research Interests:
We have identified the tomato I gene for resistance to the Fusarium wilt fungus Fusarium oxysporum f. sp. lycopersici (Fol) and show that it encodes a membrane-anchored leucine-rich repeat receptor-like protein (LRR-RLP). Unlike most... more
We have identified the tomato I gene for resistance to the Fusarium wilt fungus Fusarium oxysporum f. sp. lycopersici (Fol) and show that it encodes a membrane-anchored leucine-rich repeat receptor-like protein (LRR-RLP). Unlike most other LRR-RLP genes involved in plant defence, the I gene is not a member of a gene cluster and contains introns in its coding sequence. The I gene encodes a loopout domain larger than those in most other LRR-RLPs with a distinct composition rich in serine and threonine residues. The I protein also lacks a basic cytosolic domain. Instead, this domain is rich in aromatic residues that could form a second transmembrane domain. The I protein recognises the Fol Avr1 effector protein, but, unlike many other LRR-RLPs, recognition specificity is determined in the C-terminal half of the protein by polymorphic amino-acid residues in LRRs just preceding the loopout domain and in the loopout domain itself. Despite these differences, we show that I/Avr1-dependent n...
Research Interests:
Research Interests:
Research Interests:
Research Interests: Biochemistry, Biology, Membrane Proteins, Cell Biology, Mitochondria, and 15 moreMedicine, Biological Sciences, Molecular chaperones, Bacteria, Biogenesis, Proteins, Organelle biogenesis, CHEMICAL SCIENCES, Heat Shock Proteins, Eukaryotic Cells, Proteases, Adenosine Triphosphate, Molecular Sequence Data, proteolysis, and Medical and Health Sciences
Research Interests: Biochemistry, Science, Biology, Membrane Proteins, Mitochondria, and 15 moreMedicine, Multidisciplinary, Saccharomyces cerevisiae, Protein Complex Detection, Heat Shock Proteins, Amino Acid Sequence, Base Sequence, Proteases, Mitochondrial Carrier, Binding Site, Adenosine Triphosphate, Mitochondrion, Mitochondrial Proteins, Molecular Sequence Data, and binding sites
Research Interests: Genetics, Molecular Biology, Biology, Mitochondria, Medicine, and 15 moreGene expression, Protein synthesis, Biological Sciences, HSPA, Environmental Sciences, Mitochondrial DNA, Mutation, Escherichia coli, Complementation, Nucleic Acids, Gene, Cytochrome oxidase, Respiration, Intron, and Nucleotide sequence
Research Interests: Genetics, Biology, Mitochondria, Medicine, Biological Sciences, and 15 moreSaccharomyces cerevisiae, Environmental Sciences, Escherichia coli, Nucleic Acids, Gene, Bacillus subtilis, Protein Conformation, Amino Acid Sequence, Base Sequence, Open Reading Frame, Factor structure, Molecular Sequence Data, Nucleotide sequence, frameshift mutation, and Domain Model
Research Interests: Kinetics, Biology, Membrane Proteins, Cell Biology, Mitochondria, and 14 moreMedicine, Saccharomyces cerevisiae, Metalloproteinase, Biogenesis, Phenotype, Species Specificity, Base Sequence, Recombinant Proteins, Site-directed Mutagenesis, Protein Biosynthesis, Biochemistry and cell biology, Mitochondrion, Molecular Sequence Data, and Restriction Mapping
Research Interests:
Research Interests: Genetics, Microbiology, Biology, Membrane Proteins, Cell Biology, and 15 moreMitochondria, Medicine, Gene expression, Saccharomyces cerevisiae, HSPA, Gene, MITOCHONDRIAL BIOGENESIS, Cell nucleus, Genotype, Genomic Library, Carbon Source, Mitochondrion, Mitochondrial Proteins, Protein requirement, and Restriction Mapping
After a sudden shift to high osmolarity, Saccharomyces cerevisiae cells respond by transiently inducing the expression of stress-protective genes. Msn2p and Msn4p have been described as two transcription factors that determine the extent... more
After a sudden shift to high osmolarity, Saccharomyces cerevisiae cells respond by transiently inducing the expression of stress-protective genes. Msn2p and Msn4p have been described as two transcription factors that determine the extent of this response. In msn2 msn4 mutants, however, many promoters still show a distinct rise in transcriptional activity upon osmotic stress. Here we describe two structurally related nuclear factors, Msn1p and a newly identified protein, Hot1p (for high-osmolarity-induced transcription), which are also involved in osmotic stress-induced transcription. hot1 single mutants are specifically compromised in the transient induction of GPD1 and GPP2 , which encode enzymes involved in glycerol biosynthesis, and exhibit delayed glycerol accumulation after stress exposure. Similar to a gpd1 mutation, a hot1 defect can rescue cells from inappropriately high HOG pathway activity. In contrast, Hot1p has little influence on the osmotic stress induction of CTT1 , w...
Research Interests:
Research Interests: Microbiology, Biology, Cell Biology, Medicine, Gene expression, and 15 moreMultidisciplinary, Saccharomyces cerevisiae, Phosphatase, cyclic AMP, Osmotic pressure, Enzyme, Glycerol, Reproducibility of Results, Heat Shock, Calcineurin, Osmotic Stress, Protein Tyrosine Phosphatases, DNA binding proteins, Protein Kinase C, and Osmotic Shock
Research Interests: Biochemistry, Chemistry, Biology, Membrane Proteins, Medicine, and 15 moreSignal Transduction, Saccharomyces cerevisiae, Ethanol, Water Stress, Osmotic pressure, Yeast, Phosphorylation, Mitogen Activated Protein Kinase, Glycerol, Stimulation, Osmotic Stress, Sodium Chloride, Plasma Membrane, Biochemistry and cell biology, and Osmotic Shock
Rapid and reliable detection and identification of potential plant pathogens is required for taking appropriate and timely disease management measures. For many microbial species of which all strains generally are plant pathogens on a... more
Rapid and reliable detection and identification of potential plant pathogens is required for taking appropriate and timely disease management measures. For many microbial species of which all strains generally are plant pathogens on a known host range, this has become quite straightforward. However, for some fungal species this is quite a challenge. One of these is Fusarium oxysporum Schlechtend:Fr., which, as a species, has a very broad host range, while individual strains are usually highly host-specific. Moreover, many strains of this fungus are non-pathogenic soil inhabitants. Thus, with regard to effective disease management, identification below the species level is highly desirable. So far, the genetic basis of host specificity in F. oxysporum is poorly understood. Furthermore, strains that infect a particular plant species are not necessarily more closely related to each other than to strains that infect other hosts. Despite these difficulties, recently an increasing number of studies have reported the successful development of molecular markers to discriminate F. oxysporum strains below the species level.
Research Interests: Genetics, Biology, Medicine, Plant diseases, Fusarium, and 15 moreFusarium oxysporum, Genotype, Chemical Industry, Molecular Marker, Fungus, Plant species, Host Specificity, Plant Pathogen, Host Range, Species Specificity, Disease Management, Virulence Factors, Genetic Markers, Pest Management Science, and ENVIRONMENTAL SCIENCE AND MANAGEMENT
A major part of the transcriptional response of yeast cells to osmotic shock is controlled by the HOG pathway and several downstream transcription factors. Sko1p is a repressor that mediates HOG pathway-dependent regulation by binding to... more
A major part of the transcriptional response of yeast cells to osmotic shock is controlled by the HOG pathway and several downstream transcription factors. Sko1p is a repressor that mediates HOG pathway-dependent regulation by binding to CRE sites in target promoters. Here, we report five target genes of Hog1p-Sko1p: GRE2, AHP1, SFA1, GLR1 and YML131w. The two CREs in the GRE2 promoter function as activating sequences and, hence, bind (an) activator protein(s). However, the two other yeast CRE-binding proteins, Aca1p and Aca2p, are not involved in regulation of the GRE2 promoter under osmotic stress. In the absence of the co-repressor complex Tup1p-Ssn6p/Cyc8p, which is recruited by Sko1p, stimulation by osmotic stress is still observed. These data indicate that Sko1p is not only required for repression, but also involved in induction upon osmotic shock. All five Sko1p targets encode oxidoreductases with demonstrated or predicted roles in repair of oxidative damage. Altered basal expression levels of these genes in hog1Delta and sko1Delta mutants may explain the oxidative stress phenotypes of these mutants. All five Sko1p target genes are induced by oxidative stress, and induction involves Yap1p. Although Sko1p and Yap1p appear to mediate osmotic and oxidative stress responses independently, Sko1p may affect Yap1p promoter access or activity. The five Sko1p target genes described here are suitable models for studying the interplay between osmotic and oxidative responses at the molecular and physiological levels.
Research Interests: Biology, Molecular Microbiology, Oxidative Stress, Transcription Factors, Medicine, and 15 moreSignal Transduction, Biological Sciences, Saccharomyces cerevisiae, Enzymes, Mutation, Oxidoreductases, Gene, Transcription Factor, Enzyme, Glycerol, Oxidative Damage, DNA binding proteins, Response Elements, Mitogen- Activated Protein Kinases, and Medical and Health Sciences
Research Interests:
Root colonization by Fusarium oxysporum (Fo) endophytes reduces wilt disease symptoms caused by pathogenic Fo strains. The endophytic strain Fo47, isolated from wilt suppressive soils, reduces Fusarium wilt in various crop species such as... more
Root colonization by Fusarium oxysporum (Fo) endophytes reduces wilt disease symptoms caused by pathogenic Fo strains. The endophytic strain Fo47, isolated from wilt suppressive soils, reduces Fusarium wilt in various crop species such as tomato, flax, and asparagus. How endophyte-mediated resistance (EMR) against Fusarium wilt is achieved is unclear. Here, nonpathogenic colonization by Fo47 and pathogenic colonization by Fo f.sp. lycopersici (Fol) strains were assessed in tomato roots and stems when inoculated separately or coinoculated. It is shown that Fo47 reduces Fol colonization in stems of both noncultivated and cultivated tomato species. Conversely, Fo47 colonization of coinoculated tomato stems was increased compared to single inoculated plants. Quantitative PCR of fungal colonization of roots (co)inoculated with Fo47 and/or Fol showed that pathogen colonization was drastically reduced when coinoculated with Fo47, compared with single inoculated roots. Endophytic colonizati...
Research Interests:
Research Interests:
Research Interests:
Formae speciales (ff.spp.) of the fungus Fusarium oxysporum are often polyphyletic within the species complex, making it impossible to identify them on the basis of conserved genes. However, sequences that determine host-specific... more
Formae speciales (ff.spp.) of the fungus Fusarium oxysporum are often polyphyletic within the species complex, making it impossible to identify them on the basis of conserved genes. However, sequences that determine host-specific pathogenicity may be expected to be similar between strains within the same forma specialis. Whole genome sequencing was performed on strains from five different ff.spp. (cucumerinum, niveum, melonis, radicis-cucumerinum and lycopersici). In each genome, genes for putative effectors were identified based on small size, secretion signal and vicinity to a 'miniature impala' transposable element. The candidate effector genes of all genomes were collected and the presence/absence patterns in each individual genome were clustered. Members of the same forma specialis turned out to group together, with cucurbit-infecting strains forming a supercluster separate from other ff.spp. Moreover, strains from different clonal lineages within the same forma special...
Research Interests:
Research Interests:
Research Interests:
Horizontal transfer of supernumerary or lineage-specific (LS) chromosomes has been described in a number of plant pathogenic filamentous fungi. So far it was not known whether transfer is restricted to chromosomes of certain size or... more
Horizontal transfer of supernumerary or lineage-specific (LS) chromosomes has been described in a number of plant pathogenic filamentous fungi. So far it was not known whether transfer is restricted to chromosomes of certain size or properties, or whether "core" chromosomes can also undergo horizontal transfer. We combined a directed and a non-biased approach to determine whether such restrictions exist. Selection genes were integrated into the genome of a strain of Fusarium oxysporum pathogenic on tomato, either targeted to specific chromosomes by homologous recombination or integrated randomly into the genome. By testing these strains for transfer of the marker to another strain we could confirm transfer of a previously described mobile pathogenicity chromosome. Surprisingly, we also identified strains in which (parts of) core chromosomes were transferred. Whole genome sequencing revealed that this was accompanied by the loss of the homologous region from the recipient s...
Research Interests:
Nuclear dynamics can vary widely between fungal species and between stages of development of fungal colonies. Here we compared nuclear dynamics and mitotic patterns between germlings and mature hyphae in Fusarium oxysporum . Using... more
Nuclear dynamics can vary widely between fungal species and between stages of development of fungal colonies. Here we compared nuclear dynamics and mitotic patterns between germlings and mature hyphae in Fusarium oxysporum . Using fluorescently labeled nuclei and live-cell imaging, we show that F. oxysporum is subject to a developmental transition from a uninucleate to a multinucleate state after completion of colony initiation. We observed a special type of hypha that exhibits a higher growth rate, possibly acting as a nutrient scout. The higher growth rate is associated with a higher nuclear count and mitotic waves involving 2 to 6 nuclei in the apical compartment. Further, we found that dormant nuclei of intercalary compartments can reenter the mitotic cycle, resulting in multinucleate compartments with up to 18 nuclei in a single compartment.
Research Interests:
Research Interests: Plant Biology, Biology, Innate immunity, Disease susceptibility, Plant diseases, and 15 moreFusarium, Disease resistance, Plant, Gene, Fusarium oxysporum, Genes, Gen, Immune system, Amino Acid Profile, Amino Acid Sequence, Leaves, Lycopersicon esculentum, Innate Immune System, Molecular Sequence Data, and Nicotiana benthamiana
We sequenced and annotated the genome of the filamentous fungus Fusarium graminearum , a major pathogen of cultivated cereals. Very few repetitive sequences were detected, and the process of repeat-induced point mutation, in which... more
We sequenced and annotated the genome of the filamentous fungus Fusarium graminearum , a major pathogen of cultivated cereals. Very few repetitive sequences were detected, and the process of repeat-induced point mutation, in which duplicated sequences are subject to extensive mutation, may partially account for the reduced repeat content and apparent low number of paralogous (ancestrally duplicated) genes. A second strain of F. graminearum contained more than 10,000 single-nucleotide polymorphisms, which were frequently located near telomeres and within other discrete chromosomal segments. Many highly polymorphic regions contained sets of genes implicated in plant-fungus interactions and were unusually divergent, with higher rates of recombination. These regions of genome innovation may result from selection due to interactions of F. graminearum with its plant hosts.
Research Interests: Genetics, Polymorphism, Molecular Evolution, Science, Biology, and 12 moreMedicine, Multidisciplinary, Plant diseases, Fusarium, Fusarium Graminearum, Molecular Phylogenetics and Evolution, Genome, Gene, Single Nucleotide Polymorphism, Genetic Polymorphism, Fungal genome size, and Molecular Sequence Data
Research Interests: Microbiology, Economics, Immunology, Medical Microbiology, Biology, and 15 moreMedicine, Gene expression, Phylogeny, Fusarium, Genetically modified organisms, Plant Roots, Fusarium oxysporum, Molecular cloning, Cell nucleus, Fluorescent Protein, Plant Pathogen, Amino Acid Sequence, Knock out, Lycopersicon esculentum, and Molecular Sequence Data
Research Interests: Microbiology, Immunology, Molecular Evolution, Medical Microbiology, Biology, and 15 moreInnate immunity, Medicine, Plant Resistance, Plant diseases, Fusarium, Disease resistance, Disease Control, Fusarium oxysporum, Plant Pathogen, Plant immunity, Arms Race, PLANT PROTEINS, Host Plant, Lycopersicon esculentum, and Innate Immune System
Research Interests: Genetics, Economics, Biology, Fungi, Genome Size, and 15 moreHorizontal Gene Transfer, Medicine, Phylogeny, Fusarium Graminearum, Genome, Gene Duplication, Fusarium solani, Chromosome, Fungal genome size, Gel electrophoresis, Nectria Haematococca, Chromosomes, Fungal, Lawrence Berkeley Laboratory, and opportunistic infection
The protein content of tomato (Lycopersicon esculentum) xylem sap was found to change dramatically upon infection with the vascular wilt fungus Fusarium oxysporum. Peptide mass fingerprinting and mass spectrometric sequencing were used to... more
The protein content of tomato (Lycopersicon esculentum) xylem sap was found to change dramatically upon infection with the vascular wilt fungus Fusarium oxysporum. Peptide mass fingerprinting and mass spectrometric sequencing were used to identify the most abundant proteins appearing during compatible or incompatible interactions. A new member of the PR-5 family was identified that accumulated early in both types of interaction. Other pathogenesis-related proteins appeared in compatible interactions only, concomitantly with disease development. This study demonstrates the feasibility of using proteomics for the identification of known and novel proteins in xylem sap, and provides insights into plant-pathogen interactions in vascular wilt diseases.
Research Interests: Mass Spectrometry, Biology, Proteomics, Innate immunity, Medicine, and 14 moreBiological Sciences, Phylogeny, Plant Physiology, Plant diseases, Fusarium, Plant, Tomato, Protein isoforms, Amino Acid Sequence, Base Sequence, PLANT PROTEINS, Lycopersicon esculentum, Molecular Sequence Data, and Protein content
Research Interests: Genetics, Genomics, Molecular Evolution, Comparative Genomics, Biology, and 15 moreMedicine, Multidisciplinary, Nature, Phylogeny, General, Fusarium, Fusarium Graminearum, Molecular Phylogenetics and Evolution, Phenotype, Fusarium oxysporum, Fungal Pathogens, Fungal genome size, Host Specificity, Proteome, and Synteny
I-3-Mediated resistance of tomato against Fusarium wilt disease caused by Fusarium oxysporum f. sp. lycopersici depends on Six1, a protein that is secreted by the fungus during colonization of the xylem. Among natural isolates of F.... more
I-3-Mediated resistance of tomato against Fusarium wilt disease caused by Fusarium oxysporum f. sp. lycopersici depends on Six1, a protein that is secreted by the fungus during colonization of the xylem. Among natural isolates of F. oxysporum f. sp. lycopersici are several that are virulent on a tomato line carrying only the I-3 resistance gene. However, evasion of I-3-mediated resistance by these isolates is not correlated with mutation of the SIX1 gene. Moreover, the SIX1 gene of an I-3-virulent isolate was shown to be fully functional in that i) the gene product is secreted in xylem sap, ii) deletion leads to a further increase in virulence on the I-3 line as well as reduced virulence on susceptible lines, and iii) the gene confers full avirulence on the I-3 line when transferred to another genetic background. Remarkably, all I-3-virulent isolates were of race 1, suggesting a link between the presence of AVR1 and evasion of I-3-mediated resistance.
Research Interests:
Research Interests:
SUMMARY Secreted proteins are known to play decisive roles in plant-fungus interactions. To study the molecular details of the interaction between the xylem-colonizing, plant-pathogenic fungus Fusarium oxysporum and tomato, the... more
SUMMARY Secreted proteins are known to play decisive roles in plant-fungus interactions. To study the molecular details of the interaction between the xylem-colonizing, plant-pathogenic fungus Fusarium oxysporum and tomato, the composition of the xylem sap proteome of infected tomato plants was investigated and compared with that of healthy plants. Two-dimensional gel separation and mass spectrometry yielded peptide masses and peptide sequences of 33 different proteins. Despite the absence of complete genome sequences of either tomato or F. oxysporum, 21 proteins were identified as tomato proteins and seven as fungal proteins. Thirteen of the tomato proteins were specific for infected plants. Sixteen tomato proteins were found in xylem sap for the first time, four of which were identified based on matches to expressed sequences only. Coding sequences for new proteins from F. oxysporum were identified through either direct matching to a database sequence, matching of peptide sequences to genome or expressed sequence tag databases of other Fusarium species, or PCR with degenerate primers on cDNA derived from infected plants followed by screening of a F. oxysporum BAC library. Together, these findings provide an excellent basis for further exploration of the interaction between xylem-colonizing pathogens and their hosts.
Research Interests:
A 12 kDa cysteine-rich protein is secreted by Fusarium oxysporum f. sp. lycopersici during colonization of tomato xylem vessels. Peptide sequences obtained with mass spectrometry allowed identification of the coding sequence. The gene... more
A 12 kDa cysteine-rich protein is secreted by Fusarium oxysporum f. sp. lycopersici during colonization of tomato xylem vessels. Peptide sequences obtained with mass spectrometry allowed identification of the coding sequence. The gene encodes a 32 kDa protein, designated Six1 for secreted in xylem 1. The central part of Six1 corresponds to the 12 kDa protein found in xylem sap of infected plants. A mutant that had gained virulence on a tomato line with the I-3 resistance gene was found to have lost the SIX1 gene along with neighbouring sequences. Transformation of this mutant with SIX1 restored avirulence on the I-3 line. Conversely, deletion of the SIX1 gene in a wild-type strain results in breaking of I-3-mediated resistance. These results suggest that I-3-mediated resistance is based on recognition of Six1 secreted in xylem vessels.
Research Interests: Mass Spectrometry, Biology, Molecular Microbiology, Innate immunity, Medicine, and 15 moreBiological Sciences, Molecular, Protein Design, Fusarium, Genetic transformation, Tomato, Fusarium oxysporum, Cysteine, Amino Acid Sequence, Plant Disease Resistance, Lycopersicon esculentum, Protein requirement, Molecular Sequence Data, Mycoses, and Medical and Health Sciences
Research Interests:
Research Interests: Microbiology, Phylogenetics, Plant Biology, Biology, Evolution, and 15 moreMedicine, Gene expression, Phylogeny, Plant diseases, Fusarium, Evolutionary History, Fusarium oxysporum, Genes, Intraspecific Variation, Host Specificity, Plant Pathogen, Pathogenicity, Hosts, Molecular Sequence Data, and alleles
Research Interests: Economics, Polymorphism, Biology, Evolution, Medicine, and 15 moreBiological Sciences, Virulence, Identification, Plant diseases, Fusarium, Disease resistance, Gene, Fusarium oxysporum, Gen, Genotype, Virulence Factors, Pathogenicity, Lycopersicon esculentum, Molecular Sequence Data, and Medical and Health Sciences
Research Interests:
Fusarium oxysporum is an asexual fungus that inhabits soils throughout the world. As a species, F. oxysporum can infect a very broad range of plants and cause wilt or root rot disease. Single isolates of F. oxysporum, however, usually... more
Fusarium oxysporum is an asexual fungus that inhabits soils throughout the world. As a species, F. oxysporum can infect a very broad range of plants and cause wilt or root rot disease. Single isolates of F. oxysporum, however, usually infect one or a few plant species only. They have therefore been grouped into formae speciales (f.sp.) based on host specificity. Isolates able to cause tomato wilt (f.sp. lycopersici) do not have a single common ancestor within the F. oxysporum species complex. Here we show that, despite their polyphyletic origin, isolates belonging to f.sp. lycopersici all contain an identical genomic region of at least 8 kb that is absent in other formae speciales and non-pathogenic isolates, and comprises the genes SIX1, SIX2 and SHH1. In addition, SIX3, which lies elsewhere on the same chromosome, is also unique for f.sp. lycopersici. SIX1 encodes a virulence factor towards tomato, and the Six1, Six2 and Six3 proteins are secreted in xylem during colonization of tomato plants. We speculate that these genes may be part of a larger, dispensable region of the genome that confers the ability to cause tomato wilt and has spread among clonal lines of F. oxysporum through horizontal gene transfer. Our findings also have practical implications for the detection and identification of f.sp. lycopersici.