Medicago truncatula R108 in symbiosis with rhizobia wt or rhizobia mutant for BacA. Comparison of the transcriptomic response of Medicago truncatula plants.
ABSTRACT: 12plex_medicago_2013-08 - r108 in symbiosis with rhizobia wt or rhizobia mutant for baca. - Two experiments to compare the transcriptomic response of medicago plants: Agar medium versus Phytagel medium (exp1) and rhizobium WT versus BacA (exp2). - Medicago truncatula ecotype R108 was inoculated with the symbiotic rhizobium Sinorhizobium meliloti strain Sm1021 and with its derivative mutant delta bacA. Nodules were collected 13 days after inoculation, and RNA were prepared for transcriptome analysis, there were three biological independant experiements. Overall design: rhizobium WT versus BacA. 3 dye-swap - gene knock out
Project description:The involvement of ROS in the legume – Rhizobium symbiotic interaction has been highlighted (Santos et al., 2001; Rubio et al., 2004). This interaction is characterized by the formation of a new organ on the root, the nodule and by the penetration, in parallel, of the bacteria into the root tissue via an infection thread (IT) (Parniske and Downie, 2003; Gage, 2004). H2O2 production has been shown in ITs during the Medicago – Sinorhizobium meliloti interaction (Santos et al., 2001). Moreover, S. meliloti mutants impaired in H2O2 detoxification mechanism possess in planta symbiotic phenotypes. As H2O2 production is known to orchestrate plant gene expression, our goal is focused on identifying the H2O2 regulated genes in the symbiotic process. We focus our analysis in the M. truncatula transcriptome as we are characterising the S. meliloti H2O2 transcriptome. -M. truncatula seedlings were grown in axenic condition on modified Fahraeus medium during seven days. Then they were transferred on new plates supplemented either with dimethyl sulfoxide (DMSO, mock treatement) or diphenylene iodonium (DPI, 10 µM). Twenty four hours later, they were inoculated either with water (mock inoculation; DMSO-H2O and DPI-H2O) or wild type S. meliloti 2011 strain (DMSO-INOC and DPI-INOC). Roots without apexes were harvested 48 hours after inoculation. After RNA extraction (Trizol), quality of the treatment was verified by RT-PCR (ENOD11: inoculation efficiency; GSHS1: DNA contamination; MTC27: constitutive) Keywords: treated vs untreated comparison Overall design: 8 arrays - Medicago
Project description:affy_med_2011_06 - affy_med_2011_06 - Legume plants establish a symbiotic interaction with soil bacteria called rhizobia. A complex molecular dialogue between the two partners is necessary for the successful infection and organogenesis processes that will ultimately result in the formation of a nitrogen fixing nodule. During a M. truncatula Tnt1 mutant screen, a new class of symbiotic mutant called noot (nodule root) was identified. This original single recessive mutant develops a root in apical position of nodules that are colonized by bacteria and functional for nitrogen fixation. This conversion suggests that the legume nodule morphogenetic pathway may be derived from a root program. We cloned the NOOT gene and showed that it corresponds to Pisum sativum COCH (Ferguson and Reid, 2005, Plant Cell Physiol 46, 1583-1589). The goal of this project is to compare the transcriptomes from wild type nodules and roots to the noot nodule one. This will allow us to unravel the similarity and differences between the wild type and mutant nodule transcriptomes but also to know which developmental pathway is under the control of the NOOT gene. --Seeds of the WT and noot mutant lines (two mutant alleles: Tnk507 and NF2717) were surface sterilized and placed at 4°C for three days on a minimal BNM medium square plate (12cm X 12cm). Seeds were germinated at room temperature and 10 seeds were placed in a row on nitrogen poor (BNM) plate. Seedlings were inoculated using Sinorhizobium meliloti Rm41 for nodule production. Some WT plants were not infected by the bacteria in order to collect roots. Nodules and roots were harvested 18 to 21 days post inoculation. Each experimental repetition (3 WT nodules, 3 WT roots and 2 mutant nodules of each allele) was harvested at a separated day. RNA preparations were done using a Quiagen Kit. Overall design: 10 arrays - Medicago; gene knock out,organ comparison
Project description:A transcriptome analysis of developing abi5 and wild type (R108) seeds from Medicago truncatula was performed to decipher the role of ABI54 in the regulation of late seed maturation and seed longevity. Overall design: Transcriptome of Medicago WT (R108 background) lines (3 replicates) compared with two Medicago Tnt1 insertion lines in Medtr7g104480, named abi5-1 (NF4383) and abi5-2 (NF3376) using the Medicago_v1 NimbleGen chip
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 Overall design: 24 arrays - Medicago
Project description:Plant pathogenic bacteria disseminate and survive through transmission to and by seeds of hosts and non-hosts plants. To investigate the interaction between xanthomonads and developing seeds of Medicago truncatula, plants at the ﬂower bud stage were spray inoculated until runoff with xanthomonads suspensions. Using the Medicago NimbleGen chip, a transcriptomic analysis was performed on seeds to characterize the molecular dialogue between Xanthomonas campestris pv. campestris in an incompatible situation with M. truncatula seeds and Xanthomonas alfalfae pv. alfalfae in a compatible situation at two developmental time points (16 and 32 days atfter pollination (DAP). Six-condition experiment, 16dap_Mock versus 16dap_Xaa, 16dap_Mock versus 16dap_Xcc, 32dap_Mock versus 32dap_Xaa, 32dap_Mock versus 32dap_Xcc. Biological replicates: 6 controls (16dap_Mock, 32dap_Mock), 12 treatments (16dap_Xaa, 16dap_Xcc, 32dap_Xaa, 32dap_Xcc), independently grown and harvested. One replicate per array.
Project description:ABI3 is a B3-domain transcription factor that acts as a master regulator of seed maturation. To identify genes that are regulated by this transcription factor in the model legume Medicago truncatula, Medicago hairy roots were generated using Agrobacterium rhizogenes transformed with the genomic sequence of the ABI3 gene of Medicago. Using the Medicago NimbleGen chip, a transciptomic analysis was performed to identify differentially expressed genes compared to the GUS expressed control. Two-condition experiment, GUS versus genomic. Biological replicates: 3 control (35S::GUS), 3 treatment (35S::Genomic ABI3 sequence), independently grown and harvested. One replicate per array.
Project description:Little progress has been made in studying the toxicity of realistic 'non-pristine' forms of nanoparticles that presents in real soil environment. It is presently unkown whether the transformed nanoparticles in realistic environment exerts an adverse effect to rhizobium-legume symbiosis on molecular level. We used microarray to investigate the toxicogenomic responses of the model legume Medicago truncatula following 30 days exposure to three different types of biosolids (control biosolids (control BS), a mixture of Ag, ZnO and TiO2 manufactured nanomaterials added biosolids (Nano BS) and a corresponding bulk metals added biosolids (Bulk BS) ) amended soil that were aged for 6 months prior to exposure in pot experiment. Overall design: Our Genechip® Medicago Genome Array is designed specially to monitor gene expression in Medicago truncatula, Medicago sativa, and the symbiotic organism Sinorhizobium meliloti. For our study, RNA were extracted from shoots and roots of Medicago truncatula that exposure to control, Bulk and Nano BS treatments for 30 days, and used for all hybridization on Affymetrix microarray. The objective of our study is to investigate the molecular mechanisms of toxicity of Nano BS in comparison with their counterpart Bulk BS treatment, using a commercial Medicago truncatula microarrays.
Project description:Legumes, in interaction with resistant rhizobia, combined both moderate tolerance and accumulation of metal(loids) in roots, with the ability to grow without nitrogen supply (Pajuelo et al., 2011). This quality has attracted attention for phytostabilisation of polluted soils (Reichman, 2007). Physiological studies suggest that low arsenite concentrations lead to a decrease of nodulation process (Dary et al., 2010; Pajuelo et al., 2008). Moreover, Lafuente et al. (2010) described a reduction in the expression patterns of nodulins genes in the presence of arsenite. Nevertheless, a global transcriptomic analysis has never been approached. In order to decipher the genetic regulation underlying the arsenite effect on the model symbiotic interaction Medicago-Sinorhizobium, we have performed a meta-analysis of three different hybridizations. These compare transcriptomic profiles of roots cultivated under different treatments (±25 µM arsenite, ±rhizobia).