Citron C.A.,Institute For Organische Chemie |
Brock N.L.,Institute For Organische Chemie |
Tudzynski B.,Institute For Biologie Und Biotechnologie Der Pflanzen |
Dickschat J.S.,Institute For Organische Chemie
Chemical Communications | Year: 2014
Synthetic [2-13C]mevalonolactone was fed to the gibberellin producer Fusarium fujikuroi and its incorporation into four known terpenoids was investigated by 13C NMR analysis of crude culture extracts. The experiments gave detailed insights into the mechanisms of terpene biosynthesis by this fungus. © the Partner Organisations 2014.
Tsavkelova E.,Tel Aviv University |
Tsavkelova E.,Moscow State University |
Oeser B.,Institute For Biologie Und Biotechnologie Der Pflanzen |
Oren-Young L.,Tel Aviv University |
And 4 more authors.
Fungal Genetics and Biology | Year: 2012
The plant hormone indole-3-acetic acid (IAA) can be synthesized from tryptophan via the intermediate indole-3-acetamide (IAM). The two genes, IaaM (encoding tryptophan monooxygenase) and IaaH (encoding indole-3-acetamide hydrolase) that constitute the IAM pathway have been described in plant-associated bacteria. We have identified putative homologs of the bacterial IaaM and IaaH genes in four Fusarium species - Fusarium proliferatum, Fusarium verticillioides, Fusarium fujikuroi, and Fusarium oxysporum. In all four species the two genes are organized next to each other in a head to head orientation and are separated by a short non-coding region. However, the pathway is fully functional only in the orchid endophytic strain F. proliferatum ET1, which produces significant amounts of IAM and IAA. Minor amounts of IAM are produced by the corn pathogen F. verticillioides strain 149, while in the two other species, the rice pathogen F. fujikuroi strain m567 and the tomato pathogen F. oxysporum f. sp. lycopersici strain 42-87 the IAM pathway is inactive. Deletion of the entire gene locus in F. proliferatum ET1 resulted in drastic reduction of IAA production. Conversely, transgenic strains of F. fujikuroi over-expressing the F. proliferatum IAM genes produced elevated levels of both IAM and IAA. Analysis of the intergenic promoter region in F. proliferatum showed that transcriptional activation in direction of the IaaH gene is about 3-fold stronger than in direction of the IaaM gene. The regulation of the IAM genes and the limiting factors of IAA production via the IAM pathway are discussed. © 2011 Elsevier Inc.
Marschall R.,Institute For Biologie Und Biotechnologie Der Pflanzen |
Tudzynski P.,Institute For Biologie Und Biotechnologie Der Pflanzen
Molecular Microbiology | Year: 2016
NADPH oxidases (Nox) produce reactive oxygen species (ROS) in multicellular eukaryotic organisms. They trigger defense reactions ('oxidative burst') - in phagocytes and plant cells -, and are involved in a broad range of differentiation processes. Fungal Nox-complexes play a central role in vegetative, sexual and pathogenic processes. In contrast to mammalian systems, knowledge is limited about composition, localisation and connection to major signaling cascades in fungi. Here, we characterize a fungal homolog of the RasGAP scaffold protein IQGAP, which links several major signaling processes, including Nox in mammalian cell lines. We show that BcIqg1 interacts directly with a cytosolic, regulatory component (BcRac) and a membrane-associated subunit (BcNoxD) of a Nox-complex in the pathogen Botrytis cinerea. Thus, this protein may be a scaffold that mediates interaction of the catalytic subunits with the regulator BcNoxR. The protein interacts with modules of the MAP kinase- and calcium-dependent signaling pathways. Functional analysis of BcIqg1 substantiated its involvement in different signaling pathways. It mediates the Ca2+-triggered nuclear translocation of-BcCRZ1 and the MAP kinase BcBmp1. BcIqg1 is involved in resistance against oxidative and membrane stress and is required for several developmental processes including formation of sclerotia, conidial anastomosis tubes and infection cushions as well as for virulence. © 2016 John Wiley & Sons Ltd.
Nanni V.,University of Bologna |
Schumacher J.,Institute For Biologie Und Biotechnologie Der Pflanzen |
Giacomelli L.,Research and Innovation Center |
Brazzale D.,Research and Innovation Center |
And 4 more authors.
Plant Pathology | Year: 2014
The genome of Vitis vinifera contains 79 defensin-like (DEFL) gene sequences, classified in four groups based on peptide sequence similarity. Group-2 DEFL proteins are highly conserved peptides with 10 cysteine residues, and include VvAMP2, a defensin active against the fungal pathogen Botrytis cinerea. Here, quantitative reverse transcription-PCR (qRT-PCR) analysis was used to show that group-2 DEFLs are specifically expressed in grapevine inflorescences, with the highest level in pollen/stamen, and weak expression in calyptrae and carpels. Immunofluorescence microscopy showed that the protein accumulates in pollen grains and in specific areas of the ovary parenchyma, suggesting a role in grapevine fertilization. Antimicrobial tests showed that VvAMP2 inhibits the growth of B. cinerea, but not of other fungal pathogens, nor bacteria. Fluorescence microscopy analysis of B. cinerea cells treated with VvAMP2 revealed that this defensin is first internalized and then leads to membrane permeabilization, suggesting that membrane damage is a secondary effect of this plant defensin. To identify possible intracellular targets of VvAMP2, its inhibitory action was tested on 54 B. cinerea mutants, with deletions in key signalling genes. The ΔBcATF1 transcription factor mutant, impaired in regulation of cell wall and oxidative stress genes, completely lost sensitivity to VvAMP2. Mutants lacking the Rho-type GTPase BcCDC42, the G protein-coupled receptor BcGPR3 and the putative scaffold protein BcBEM1, showed very low sensitivity. © 2014 British Society for Plant Pathology.
Amselem J.,French National Institute for Agricultural Research |
Cuomo C.A.,The Broad Institute of MIT and Harvard |
van Kan J.A.L.,Wageningen University |
Viaud M.,French National Institute for Agricultural Research |
And 74 more authors.
PLoS Genetics | Year: 2011
Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38-39 Mb genomes include 11,860-14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared to <1% of B. cinerea. The arsenal of genes associated with necrotrophic processes is similar between the species, including genes involved in plant cell wall degradation and oxalic acid production. Analysis of secondary metabolism gene clusters revealed an expansion in number and diversity of B. cinerea-specific secondary metabolites relative to S. sclerotiorum. The potential diversity in secondary metabolism might be involved in adaptation to specific ecological niches. Comparative genome analysis revealed the basis of differing sexual mating compatibility systems between S. sclerotiorum and B. cinerea. The organization of the mating-type loci differs, and their structures provide evidence for the evolution of heterothallism from homothallism. These data shed light on the evolutionary and mechanistic bases of the genetically complex traits of necrotrophic pathogenicity and sexual mating. This resource should facilitate the functional studies designed to better understand what makes these fungi such successful and persistent pathogens of agronomic crops. © 2011 Amselem et al.