Project description:The response mechanisms, recognition and specificity of conifer trees during interaction with pathogenic, saprotrophic or symbiotic ectomycorrhizal fungus were investigated. The roots of Pinus sylvestris were challenged for five days with either Heterobasidion annosum (a pathogenic root rot fungus which attacks Norway spruce, Scots pine and broad leaf trees); Laccaria bicolor (an obligate ectomycorrhizal symbiont); or Trichoderma aureoviride (an obligate saprotroph). The gene expression data from cDNA micro-arrays consisting of 2176 Pinus taeda genes were analysed using 2-interconnected mixed linear model statistical approach. The result of the pairwise comparisons of the different treatments against un-inoculated control led to identification of genes specifically differentially expressed in the pathogenic, saprotrophic and symbiotic interactions. The results were compared with similar data obtained for two other interaction stages: 1 and 15 days post inoculation. The result of this comprehensive expression profiling will hopefully shed more light on the mechanistic basis for recognition and response of conifer trees to pathogenic and non-pathogenic fungi. Keywords: stress response
Project description:The response mechanisms, recognition and specificity of conifer trees during interaction with pathogenic, saprotrophic or symbiotic ectomycorrhizal fungus were investigated. The roots of Pinus sylvestris were challenged for fifteen days with either Heterobasidion annosum (a pathogenic root rot fungus which attacks Norway spruce, Scots pine and broad leaf trees); Laccaria bicolor (an obligate ectomycorrhizal symbiont); or Trichoderma aureoviride (an obligate saprotroph). The gene expression data from cDNA micro-arrays consisting of 2176 Pinus taeda genes were analysed using 2-interconnected mixed linear model statistical approach. The result of the pairwise comparisons of the different treatments against un-inoculated control led to identification of genes specifically differentially expressed in the pathogenic, saprotrophic and symbiotic interactions. The results were compared with similar data obtained for two other interaction stages: 1 and 5 days post inoculation. The result of this comprehensive expression profiling will hopefully shed more light on the mechanistic basis for recognition and response of conifer trees to pathogenic and non-pathogenic fungi. Keywords: stress response
Project description:The genus Armillaria spp. (Fungi, Basidiomycota) includes devastating pathogens of temperate forests and saprotrophs that decay wood. Pathogenic and saprotrophic Armillaria species can efficiently colonize and decay woody substrates, however, mechanisms of wood penetration and colonization are poorly known. We assayed the colonization and decay of autoclaved spruce roots using the conifer-specialists Armillaria ostoyae and A. cepistipes using transcriptomic and proteomic data. Transcript and protein levels were altered more extensively in the saprotrophic A. cepistipes than in the pathogenic A. ostoyae and in invasive mycelia of both species compared to their rhizomorphs. Diverse suites of carbohydrate-active enzyme genes (CAZymes), in particular pectinolytic ones and expansins, were upregulated in both species, whereas ligninolytic genes were mostly downregulated. Our gene expression data, together with previous comparative genomic and decay-chemistry analyses suggest that wood decay by Armillaria differs from that of typical white rot fungi and shows features resembling soft rot. We propose that Armillaria species have modified the ancestral white rot machinery so that it allows for selective ligninolysis based on environmental conditions and/or host types.
Project description:The genus Armillaria spp. (Fungi, Basidiomycota) includes devastating pathogens of temperate forests and saprotrophs that decay wood. Pathogenic and saprotrophic Armillaria species can efficiently colonize and decay woody substrates, however, mechanisms of wood penetration and colonization are poorly known. We assayed the colonization and decay of autoclaved spruce roots using the conifer-specialists Armillaria ostoyae and A. cepistipes using transcriptomic and proteomic data. Transcript and protein levels were altered more extensively in the saprotrophic A. cepistipes than in the pathogenic A. ostoyae and in invasive mycelia of both species compared to their rhizomorphs. Diverse suites of carbohydrate-active enzyme genes (CAZymes), in particular pectinolytic ones and expansins, were upregulated in both species, whereas ligninolytic genes were mostly downregulated. Our gene expression data, together with previous comparative genomic and decay-chemistry analyses suggest that wood decay by Armillaria differs from that of typical white rot fungi and shows features resembling soft rot. We propose that Armillaria species have modified the ancestral white rot machinery so that it allows for selective ligninolysis based on environmental conditions and/or host types.
2020-05-04 | GSE149701 | GEO
Project description:Rhizosphere Microbial Ecological Characteristics of Strawberry Root Rot
Project description:Wood-degrading fungi play a critical role in global carbon cycling, and their varied mechanisms for deconstruction offer pathways for industrial bioconversion. In this study, we used comparative genomics to isolate upregulation patterns among fungi with brown rot (carbohydrate-selective) or white rot (lignin-degrading) nutritional modes. Specifically, we used whole-transcriptome profiling to compare early, middle, and late decay stages on wood wafers, matching differentially-expressed gene (DEG) patterns with fungal growth and enzyme activities. This approach highlighted 34 genes uniquely upregulated in early brown rot stages, with notable candidates involved in generating reactive oxygen species (ROS) as a pretreatment mechanism during brown rot. This approach further isolated 18 genes in late brown rot stages that may be adapted to handle oxidatively-reacted lignocellulose components. By summing gene expression levels in functional classes, we also identified a broad and reliable distinction in glycoside hydrolase (GH) versus lignocellulose oxidative (LOX) transcript counts that may reflect the energy investment burden of lignin-degrading machinery among white rot fungi.
Project description:Macrophomina phaseolina is a global devastating necrotrophic fungal pathogen. It causes charcoal rot disease in more than 500 host plants. It is essential to understand the host microbe interaction and the diseases pathogenesis which can ensure global agricultural crop production and security. An array of virulence factors of M. phaseolina were identified which were found to be involved in pathogenesis of other plant pathogenic fungi also. In conclusion the present study has provided a better understanding of how necrotrophic fungi M. phaseolina modulates host plant defensive processes.
Project description:White-rot basidiomycete fungi are potent degraders of plant biomass with the ability to mineralize all lignocellulose components. Recent comparative genomics studies showed that these fungi use a wide diversity of enzymes for wood degradation. In order to improve our understanding on the enzymatic mechanisms leading to lignocellulose breakdown, we analysed the early response of the white-rot fungus Pycnoporus coccineus CIRM-BRFM310 to various lignocellulosic substrates at two time points; Day 3 and Day 7.
Project description:Rice (Oryza sativa L.) is one of the most important staple foods in the world, feeding more than 50% of the human population. One of its most damaging pathogens, with major impact on rice yield, is the migratory root rot nematode Hirschmanniella oryzae. In comparison with the existing knowledge on the infection process of dicots by sedentary nematodes, far less is known about the interaction between monocot plants and nematodes or plant interactions with migratory nematode species. Therefore, to gain deeper insight into the systemic transcriptional changes in rice after migratory root rot nematode infection we have performed mRNA-Seq on the shoots of root rot nematode infected rice plants. The observations were independently validated using qRT-PCR and biochemical analyses. This research reveals significant modifications in the metabolism of the plant, with a general suppression of chlorophyll biosynthesis, and primary metabolic processes involved in plant growth . Differential expression analysis between controls rice shoots and shoots from root rot nematode (H. oryzae) infected rice at two time points.