Project description:Orchids form an endomycorrhizal association with fungal symbionts mainly belonging to Basidiomycetes. The molecular events taking place in orchid mycorrhiza are poorly understood, although the cellular changes necessary to accommodate the fungus and to control nutrient exchange between the symbionts imply a modulation of gene expression. In this study, we used proteomic and transcriptomic approaches to identify changes in the steady-state levels of proteins and transcripts in roots of the green terrestrial orchid Oeceoclades maculata. When mycorrhizal and non-mycorrhizal roots from the same individuals of O. maculata were compared, 94 proteins showed differential accumulation using the label-free protein quantitation approach, 86 using isobaric tagging (iTRAQ) and 60 using 2D-differential electrophoresis. After de novo assembly of transcriptomic data, 11,179 plant transcripts were found to be differentially expressed and 2175 were successfully annotated. The annotated plant transcripts allowed the identification of up- and down-regulated metabolic pathways in mycorrhizal roots, as compared to non-mycorrhizal roots. Overall, proteomics and transcriptomics revealed in mycorrhizal roots increased levels of transcription factors and nutrient transporters, as well as ethylene-related proteins. The expression pattern of proteins and transcripts involved in plant defense responses suggest that plant defense is reduced in mycorrhizal roots. These results expand our current knowledge towards a better understanding of the orchid mycorrhizal symbiosis in adult plants under natural conditions.
Project description:Illumina HiSeq technology was used to generate mRNA profiles from Helianthemum almeriense in three different conditions: non-mycorrhizal plant, well-watered mycorrhizal plant and drought-stressed mycorrhizal plant. Paired-end reads of 75 bp were generated and aligned to a de novo transcriptome assembly from H. almeriense, which was performed using Megahit version 1.1.3 and transcripts from each condition were mapped onto the de novo transcriptome with Bowtie2 version 2.3.0.
Project description:Purpose: We here wanted to describe the gene regulation of Gigaspora rosea in association with phyllogenetically divergent plant hosts, and compare these results with gene regulation occuring in R. irregularis, the model arbuscular mycorrhizal fungus. Methods: mRNA from Medicago truncatula (legume), Brachypodium distachyon (grass) in association with G. rosea, and extra radical mycelium of G.rosea were sequenced by Illumina. Reads were mapped on a in-house de novo transcript assembly with the software CLC workbench. Fungal gene expression in the different host plants was compared to extra radical hyphae as reference. Results: Sets of 1891 and 1566 G. rosea genes were highly overexpressed (fold change >5 ; FDR <0,05 and experimental value difference > 10) , in M. truncatula and B. distachyon respectively compared to ERM, among which 802 of them were up-regulated in both plants. Non common up-regulated genes are mainly found non statistically robust in one condition. Conclusions: Our study represents the first transcriptomic analysis on several hosts for this fungal species. These results showed that the interaction between plants and AMF is highly conserved.
Project description:Roots of Arabidopsis thaliana do not engage in symbiotic association with mycorrhizal fungi but host taxonomically diverse fungal communities that influence health and disease states. We sequenced the genomes of 41 isolates representative of the A. thaliana root mycobiota for comparative analysis with 79 other plant-associated fungi. We report that root mycobiota members evolved from ancestors having diverse lifestyles and retained diverse repertoires of plant cell wall-degrading enzymes (PCWDEs) and effector-like small secreted proteins. We identified a set of 84 gene families predicting best endophytism, including families encoding PCWDEs acting on xylan (GH10) and cellulose (AA9). These genes also belong to a core transcriptional response induced by phylogenetically-distant mycobiota members in A. thaliana roots. Recolonization experiments with individual fungi indicated that strains with detrimental effects in mono-association with the host not only colonize roots more aggressively than those with beneficial activities but also dominate in natural root samples. We identified and validated the pectin degrading enzyme family PL1_7 as a key component linking aggressiveness of endophytic colonization to plant health.
Project description:Arbuscular mycorrhiza (AM) interactions between plants and Glomeromycota fungi primarily support phosphate aquisition of most terrestrial plant species. To unravel gene expression during early stages of Medicago truncatula root colonization by AM fungi, we used genome-wide transcriptome profiling based on mycorrhizal root fragments enriched for early fungal infection stages. We used Medicago GeneChips to detail the global programme of gene expression in response to early stages of colonization by arbuscular mycorrhizal fungi and identified genes differentially expressed during these early stages.
2012-03-28 | GSE34617 | GEO
Project description:Arbucular mycorrhizal fungal community
Project description:Arbuscular mycorrhizal fungi arguably form the most successful and wide-spread endosymbiosis with plants. In general terms there is very little host-specificity in this interaction, indicating an extremely broad compatibility. However, host preferences as well as varying symbiotic efficiencies have been observed, the molecular basis of which is still largely unknown. Secreted proteins (SPs) may act as fungal effectors to control symbiotic efficiency in a host-dependent manner. Therefore, we studied whether AM fungi adjust their secretome in a host- and stage-dependent manner to contribute to their extremely wide host-range. We investigated the expression of SP encoding genes of R. irregularis DAOM197198 in three evolutionary distantly related plant species, Medicago truncatula (Medicago), Nicotiana benthamiana (Nicotiana) and Allium schoenoprasum (Chives). In addition we used laser microdissection in combination with RNAseq to study SP expression at different stages of the symbiotic interaction in Medicago. Our data indicate that the vast majority of 288 expressed SPs show equal expression levels in the interaction with all three host plants. In addition, a subset (~15%) of the SPs show significant differential expression depending on the host plant and/or environmental condition. This host-dependent expression appears to be controlled locally in the hyphal network in response to host metabolic cues. Overall, this study offers a comprehensive analysis of the R. irregularis secretome, which now offers a solid basis to direct functional studies on the role of fungal SPs in AM symbiosis.
2018-03-27 | GSE99655 | GEO
Project description:Rhizosphere fungal community of non-host plant Arabidopsis