The small RNA diversity from Medicago truncatula roots under biotic interactions evidences the environmental plasticity of the miRNAome
ABSTRACT: Plants show a remarkable plasticity to adapt their root architecture to biotic and abiotic constraints of the soil environment. Although some of these modifications are fine-tuned by miRNAs, there are still shadow zones in these regulations. In the model legume Medicago truncatula, we analyzed the small RNA (smRNA) transcriptome of roots submitted to symbiotic and pathogenic interactions. Mapping on the genome and prediction of pre-miRNA hairpins allowed the identification of 416 candidates. Out of them, we found known and novel variants of 77 miRNA families, already reported in miRBase. In addition, thanks stringent criteria of miRNA prediction, 53 mtr-miRNAs were discovered, including 27 putative miRtrons. Exploring polymorphism in 26 M. truncatula ecotypes, higher polymorphism was observed in conserved rather than legume-specific miRNA genes. An average of 19 targets, mainly involved in environmental responses and signaling, was predicted per novel miRNA. In addition, taking advantage of our large number of smRNA libraries, we identified sets of miRNAs responsive to root pathogens or to symbiotic interactions and the related Nod and myc-LCO signals. 23 libraries of small RNA (smRNA) of roots submitted to symbiotic and pathogenic interactions.
BACKGROUND: Legume roots show a remarkable plasticity to adapt their architecture to biotic and abiotic constraints, including symbiotic interactions. However, global analysis of miRNA regulation in roots is limited, and a global view of the evolution of miRNA-mediated diversification in different ecotypes is lacking. RESULTS: In the model legume Medicago truncatula, we analyze the small RNA transcriptome of roots submitted to symbiotic and pathogenic interactions. Genome mapping and a computati ...[more]
Project description:we used two-dimensional gel electrophoresis and mass spectrometry to characterize the proteome-level changes associated with salt stress response in Medicago sativa cv. Zhongmu-1 and Medicago truncatula cv. Jemalong A17 roots. The tandem mass spectrometry analysis of the differentially accumulated proteins resulted in the identification of 60 and 26 proteins in Zhongmu-1 and Jemalong A17 roots, respectively.
Project description:affy_ralstonia_medicago - Ralstonia solanacearum is the causal agent of the devastating bacterial wilt disease. Its infection process was studied with an in vitro inoculation procedure on intact roots of Medicago truncatula. The pathosystem involved susceptible A17 and resistant F83005.5 M truncatula lines infected with the pathogenic strain GMI1000. The mutant A17 line, Sickle, which showed a resistant phenotype was also part of the experiment. To identify host signaling pathway triggered by R. solanacearum infection with a focus on the involvment of ethylene, we used the Medicago Affymetrix array to monitore the expression profiles and the molecular process associated with initial symptoms development (12hpi) and colonization (72hpi). In order to maximize chances to observe differential gene expression, RNA samples were extracted from the root infection zone (root tips) -Three Medicago truncatula lines, A17, F83005.5 and sickle were inoculated with GMI1000 Ralstonai solanacearum strain (107 cfu/ml). RNA were extracted from root extremities (1 cm above the root tip) at time 0, 12h and 72h post inoculation. Three biological repeats were conducted normal vs disease comparison, time course, 27 arrays - Medicago
Project description:affy_ralstonia_peeters_medicago - We have identified two essential virulence determinants (GALA7, a type III secretion effector and HpaP, a chaperone-like protein) of Ralstonia solanacearum for the infection and colonisation of the host plant Medicago truncatula. The scope of this project is to identify the GALA7 and HpaP-specific transcriptome alteration. For this purpose wild type and mutant infected root material (13h and 72h postinfection) will be analysed on M. truncatula affymetrix chips. Medicago truncatula (A17 line) are grown in vitro on Farheus medium (with Nitrogen source) plantlets are inoculated with water R. solanacearum wt, gala7 and hpap mutants, and root tips are collected at 13h and 72h postinoculation. Experiment was performed 3 times independently. 4 bacteria conditions x 2 harvest times x 3 biological repeats = 24 samples Keywords: gene knock out,normal vs disease comparison,time course,treated vs untreated comparison 24 arrays - Medicago
Project description:The transcriptome profile of arbuscular mycorrhiza established at 4 weeks post inoculation between Medicago truncatula and Glomus mosseae as well as between Medicago truncatula and Glomus intraradices is compared
Project description:To identify host signaling pathways triggered by P. omnivora<br>infection, we used microarrays to monitor the expression profiles<br>and the molecular process associated with initial entry at 3 days post-inoculation and colonization at 5 days post-inoculation
Project description:This experiment was designed to study the interactions between Medicago truncatula and the charcoal rot pathogen Macrophomina phaeolina. Two-week-old plants grown in Magenta boxes supplied with 1/2 MS salt and 1% sucrose were inoculated with M. phaseolina covered wheat seeds, and roots were harvested at 24, 36 and 48 hours after inoculation. Control plants were mock inoculated with a sterile wheat seed, and roots were harvest 24 hours later. Pooled RNAs were used in the array experiment using Affymetrix GeneChip(r) Medicago Genome Array.