Project description:This SuperSeries is composed of the following subset Series: GSE33636: Gene expression data from Medicago truncatula plantlet roots treated with symbiotic lipochitooligosaccharides (LCOs). GSE33637: Gene expression data from Medicago truncatula mutant plantlet roots treated with Myc-LCOs. Refer to individual Series
Project description:Publication title: Pseudonodule formation by wild type and symbiotic mutant Medicago truncatula in response to auxin transport inhibitors This SuperSeries is composed of the SubSeries listed below.
Project description:Legumes interact with soil microbes, leading to the development of nitrogen-fixing root nodules and arbuscular mycorrhizal (AM) roots. While nodule initiation by diffusible lipochitooligosaccharide (LCO) Nod-factors of bacterial origin (Nod-LCOs) is well characterized, diffusible AM fungal signals were only recently identified as sulphated and non-sulphated LCOs (sMyc-LCOs and nsMyc-LCOs). Applying Myc-LCOs in parallel to Nod-LCOs, we used GeneChips to detail the global programme of gene expression in response to the external application of symbiotic LCOs.
Project description:This experiment constitutes an expression profiling approach to identify genes differentially regulated during the symbiotic interaction between the model legume Medicago truncatula and the nitrogen-fixing bacterium Sinorhizobium meliloti. Macro- and microarrays containing 6144 probes were generated on the basis of three cDNA libraries dedicated to the study of root symbiotic interactions. The experiment performed on wild-type and symbiotic mutant material led to the identification of genes either up- or down-regulated at different stages of the nodulation process.
Project description:Medicago truncatula has been selected as one of the model legume species for gene functional studies. To elucidate the functions of the very large number of genes present in plant genomes, genetic mutant resources are very useful and necessary tools. Fast Neutron (FN) mutagenesis is effective in inducing deletion mutations in genomes of diverse species. Through this method, we have generated a large mutant resource in M. truncatula. This mutant resources have been used to screen for different mutant using a forward genetics methods. We have isolated and identified a large amount of symbiotic nitrogen fixation (SNF) deficiency mutants. Here, we describe the detail procedures that are being used to characterize symbiotic mutants in M. truncatula. In recent years, whole genome sequencing has been used to speed up and scale up the deletion identification in the mutant. Using this method, we have successfully isolated a SNF defective mutant FN007 and identified that it has a large segment deletion on chromosome 3. The causal deletion in the mutant was confirmed by tail PCR amplication and sequencing. Our results illustrate the utility of whole genome sequencing analysis in the characterization of FN induced deletion mutants for gene discovery and functional studies in the M. truncatula. It is expected to improve our understanding of molecular mechanisms underlying symbiotic nitrogen fixation in legume plants to a great extent.
Project description:Legumes interact with soil microbes, leading to the development of nitrogen-fixing root nodules and arbuscular mycorrhizal (AM) roots. While nodule initiation by diffusible lipochitooligosaccharide (LCO) Nod-factors of bacterial origin (Nod-LCOs) is well characterized, diffusible AM fungal signals were only recently identified as sulphated and non-sulphated LCOs (sMyc-LCOs and nsMyc-LCOs). Applying Myc-LCOs in parallel to Nod-LCOs, we used GeneChips to detail the global programme of gene expression in response to the external application of symbiotic LCOs. To harvest tissues for transcriptome profiling, three biological replicates consisting of 20 plantlets per treatment were selected. After 6 h of incubation in the climate chamber, 10 plantlets per batch were removed from the treatment (Myc-LCOs or Nod-LCOs) or control solutions and harvested, while the other 10 remained in the respective solutions for a total of 24 h. During harvest, one mm of the root tip of each plantlet was removed and discarded. The remaining 2 to 2.5 cm of the distal root region were cut off and directly frozen in liquid nitrogen.
Project description:Publication title: Pseudonodule formation by wild type and symbiotic mutant Medicago truncatula in response to auxin transport inhibitors This SuperSeries is composed of the following subset Series: GSE27991: Expression data of Medicago truncatula Jemalong A17 roots treated with auxin transport inhibitors GSE28171: Expression data of Medicago truncatula Jemalong A17 roots treated with S. meliloti exoA mutant or auxin transport inhibitors GSE28172: Expression data of Medicago truncatula skl1-1 roots treated with S. meliloti wild-type or auxin transport inhibitors GSE28173: Genes differentially expressed in wild-type Medicago truncatula plants during nodulation Refer to individual Series
Project description:In plants and fungi the plasma membrane proton pump generates a large proton-motive force that performs essential functions in many processes, including solute transport and the control of cell elongation. Previous studies in yeast and higher plants have indicated that phosphorylation of an auto-inhibitory domain is involved in regulating pump activity. In this report we examine the Medicago truncatula plasma membrane proton pump gene family, and in particular MtAHA5. Yeast complementation assays with phosphomimetic mutations at six candidate sites support a phosphoregulatory role for two residues, suggesting a molecular model to explain early Nod factor-induced changes in the plasma membrane proton-motive force of legume root cells.
Project description:ObjectivesEarlier work in our lab identified a spontaneous mutant (likesunnsupernodulator-lss) in Medicago truncatula, resulting in increased nodulation. Molecular genetic evidence indicated the phenotype was due to an unknown lesion resulting in cis-silencing of the SUNN gene. Altered methylation of the promoter was suspected, but analysis of the SUNN promoter by bisulfite sequencing at the time of publication revealed no significant methylation differences between the SUNN promoter in wild type and lss plants. Using advances in methylome generation we compared the methylome of wild type and the lss mutant in the larger 810 kB area of the genome where lss maps.Data descriptionThe data show the distribution of types of methylation across the entire genome between A17 wild type and lss mutants, the number of differentially methylated cytosines between genotypes, and the overall pattern of gene methylation between genotypes. We expect the wild type data will be especially useful as a reference for other investigations of methylation using M. truncatula.