Project description:Z. tritici is a fungal pathogen causing the disease septoria tritici blotch, one of the most economically devastating foliar diseases in wheat. The molecular basis underlying Z. tritici growth, development and pathogenicity is not fully understood yet. Compared to the genomic investigations in this fungus, little is known about the protein expression at a systematic level. The aim of the project is to construct a comprehensive protein database of Z. tritici growing in nutrient-limiting and rich media and in vivo at a late stage of wheat infection by using 1D gel-based and SCX-based proteomics and subproteomics (intracellular and extracellular) approaches.
Project description:The hemibiotrophic fungus Zymoseptoria tritici causes Septoria tritici blotch disease of wheat (Triticum aestivum). Pathogen reproduction on wheat occurs without cell penetration, suggesting that dynamic and intimate intercellular communication occurs between fungus and plant throughout the disease cycle. We used deep RNA sequencing and metabolomics to investigate the physiology of plant and pathogen throughout an asexual reproductive cycle of Z. tritici on wheat leaves. Over 3,000 pathogen genes, more than 7,000 wheat genes, and more than 300 metabolites were differentially regulated. Intriguingly, individual fungal chromosomes contributed unequally to the overall gene expression changes. Early transcriptional down-regulation of putative host defense genes was detected in inoculated leaves. There was little evidence for fungal nutrient acquisition from the plant throughout symptomless colonization by Z. tritici, which may instead be utilizing lipid and fatty acid stores for growth. However, the fungus then subsequently manipulated specific plant carbohydrates, including fructan metabolites, during the switch to necrotrophic growth and reproduction. This switch coincided with increased expression of jasmonic acid biosynthesis genes and large-scale activation of other plant defense responses. Fungal genes encoding putative secondary metabolite clusters and secreted effector proteins were identified with distinct infection phase-specific expression patterns, although functional analysis suggested that many have overlapping/redundant functions in virulence. The pathogenic lifestyle of Z. tritici on wheat revealed through this study, involving initial defense suppression by a slow-growing extracellular and nutritionally limited pathogen followed by defense (hyper) activation during reproduction, reveals a subtle modification of the conceptual definition of hemibiotrophic plant infection.
Project description:Septoria leaf blotch is a worldwide threat for wheat and mainly controlled by the application of synthetic fungicides. The fungal pathogen responsible for this disease, Zymoseptoria tritici, was shown as highly adaptable to its host plant, but also to fungicide challenge. Over the past decades it developed resistance to most fungicides due to target site modifications. Recently isolated strains showed cross-resistance to diverse fungicides and to unrelated drugs, suggesting a resistance mechanism that seems rarer in phytopathogenic fungi, known as multidrug resistance (MDR) in other organisms. In this study we show for two Z. tritici MDR strains, MDR6 and MDR7, enhanced prochloraz efflux sensitive to the modulators amitryptiline and chlorpromazine. Efflux was also inhibited by verapamil in the MDR7strain. Transcriptomics revealed several overexpressed transporter genes in both MDR strains, out of which the expression of the MgMFS1 transporter gene was the strongest and constitutively high in tested MDR field strains. Its inactivation in the MDR6 strain abolished resistance to fungicides with different modes of action revealing its involvement in the MDR phenomenon in Z. tritici.
Project description:Septoria leaf blotch is a worldwide threat for wheat and mainly controlled by the application of synthetic fungicides. The fungal pathogen responsible for this disease, Zymoseptoria tritici, was shown as highly adaptable to its host plant, but also to fungicide challenge. Over the past decades it developed resistance to most fungicides due to target site modifications. Recently isolated strains showed cross-resistance to diverse fungicides and to unrelated drugs, suggesting a resistance mechanism that seems rarer in phytopathogenic fungi, known as multidrug resistance (MDR) in other organisms. In this study we show for two Z. tritici MDR strains, MDR6 and MDR7, enhanced prochloraz efflux sensitive to the modulators amitryptiline and chlorpromazine. Efflux was also inhibited by verapamil in the MDR7strain. Transcriptomics revealed several overexpressed transporter genes in both MDR strains, out of which the expression of the MgMFS1 transporter gene was the strongest and constitutively high in tested MDR field strains. Its inactivation in the MDR6 strain abolished resistance to fungicides with different modes of action revealing its involvement in the MDR phenomenon in Z. tritici. A total of four strains were compared, two sensitive (IPO323, S6) and two MDR strains (09-ASA-3apz; 09-CB01) with three replicates each. All strains were grown in liquid YPD medium to exponential growth.
Project description:We revealed that a rhamnolipid protects wheat against the hemibiotrophic fungal pathogen Zymoseptoria tritici. Foliar application of the biomolecule primes, during the early stages of infection, the expression of genes associated with different functional groups of genes.
Project description:Wheat (Chisenese Spring) transcriptome analyses during single and mixed infections by an avirulent and a virulent strains of Z. tritici.
Project description:We revealed that mycosubtilin, a lipopeptide from Bacillus subtilis, protects wheat against the hemibiotrophic fungal pathogen Zymoseptoria tritici. Foliar application of the biomolecule primes, during the early stages of infection, the expression of genes associated with sixteen functional groups, including responses to pathogens, abiotic and oxidative stresses, secondary metabolism, cell-wall structure and function, and primary metabolic pathways (carbohydrate, amino acid, protein, lipid, and energy metabolisms).