Project description:Lotus japonicus is a perennial legume with a small diploid genome that has been adopted as a model species for legume genetics and genomics. With the genome sequence as a backdrop (Sato et al. 2008), we have generated a gene expression atlas that provides a global view of gene expression in all major organ systems of this species, including nodule and seed development.
Project description:Model legume Lotus japonicus was subjected to non-lethal long-term salinity and profiled at the transcriptomic level. Three independent experiments were performed, testing two experimental designs: a traditional gradual acclimation following a step-wise increase of salt concentration and an initial acclimation approach (ia).
Project description:Acting in a partially redundant manner, NF-Ys were shown previously to regulate bacterial infection, including selection of a superior rhizobial strain, and to participate in mediating nodule structure formation. However, the exact mechanism(s) by which these transcriptional factors exert their symbiotic functions has remained elusive. Gene expression profiling for wild-type and Nuclear Factor YA (nf-ya)-A mutants in roots of Lotus japonicus were conducted 4 days after inoculation with Mesorhizobium loti in order to understand the interaction of NF-Ys and other genes in Lotus japonicus.
Project description:Many plant researchers have applied genomic tools to model species to identify abiotic stress responsive genes that might be useful for improving stress tolerance in crops. However, it is unclear whether this translational approach will be successful given the complexity of abiotic stress tolerance. We carried out a functional genomic (ionomic, transcriptomic and metabolomic) comparison of three model and three forage species of the genus Lotus with varying tolerance to salinity. Transcriptome analysis showed that about 60 % of expressed genes were responsive to salt treatment in one or more of the six species tested, but less than 1 % was responsive in all genotypes. Therefore, genotype-specific responses overshadowed conserved transcriptional responses to salinity and represent an impediment to translational genomics. Fortunately, 'triangulation' from multiple species enabled the identification of a core set of conserved and tolerant-specific responses that could provide durable tolerance across genotypes.
Project description:Microarray transcriptomic analysis was carried out on Lotus japonicus plants grown either under purely symbiotic conditions (Mesorhizobium loti) or under non-symbiotic conditions (no inoculation and provided with NH4NO3).
Project description:Transcriptomic profiling was carried out for leaves of Lotus japonicus plants grown with different mineral nitrogen sources (NO3-, NH4+ or NH4NO3) or under conditions of biological nitrogen fixation (Nod). Nodulated plants were inoculated with Mesorhizobium loti and watered with nitrogen-free âHornumâ medium supplemented with 3 mM KCl. Plants under different nitrogen nutritions were watered with âHornumâ nutrient solution containing 10 mM KNO3 (NO3- plants) or with 10 mM NH4Cl supplemented with 3 mM KCl (NH4+ plants) or with 5 mM NH4NO3 supplemented with 3 mM KNO3 (NH4NO3 plants). After all the plants reached the size of 7 trifoils, leaf tissue was harvested. Every harvest involved at least three independent biological replicates for each treatment.
Project description:Legume plants can establish symbiotic nitrogen fixation (SNF) with rhizobia mostly in root nodules, where rhizobia-infected cells are accompanied with uninfected cells in a mosaic pattern. Inside the mature nodules of legume, carbon and nitrogen nutrients between host plant cells and their resident bacteria are actively exchanged. To elucidate the metabolite dynamics relevant for SNF in nodules, three cell-types from nodule tissues of a model legume, Lotus japonicus, were isolated using laser microdissesction, and transcriptome analysis was done by an oligoarray with 60-mer length representing 21,495 genes. In our cell-type-specific profiling, many genes were identified as being expressed in nodules with spatial-specific manners. Among them, genes coding for metabolic enzymes were classified according to their function, and detailed data analysis figured out that secondary metabolic pathway was highly activated in nodule cortex. In particular, a number of metabolic genes for phenyl propanoid pathway were found as highly expressed genes accompanied with those encoding putative transporters of secondary metabolites. These data suggest the involvement of novel physiological function of phenylpropanoids in SNF. Gene expression in three different cell-types of Lotus japonicus nodule was measured. Three independent experiments were performed at each cell-types.
Project description:We performed proteomics of M. loti bacteroid harvested at 2, 3, and 4 WPI to disclose the transition of proteome profile during nodule maturation
Project description:To identify the regulatory targets of the R2R3-Myb transcription factor, LjMyb14, the gene was constitutively over-expressed in Lotus japonicus under the Lotus ubiquitin promoter. The gene expression levels of three biological replicates of the Lotus japonicus (MG20) were averaged and compared to the the gene expression levels of three independent lines of Lotus japonicus japonicus constituitively over expressing LjMyb14 using the Lotus ubiquitin promoter.
Project description:Soybean root hair transcriptional response to their inoculation by the symbiotic bacteria B. japonicum involved in soybean nodulation. We used the first generation of an Affymetrix microarray to quantify the abundance of the transcripts from soybean root hair cells inoculated and mock-inoculated by B. japonicum. This experiment was performed on a time-course from 6 to 48 hours after inoculation. Soybean seeds were sowed on sterile agar medium and grown for 3 days in a growth chamber before being treated with H2O (mock-inoculated) or B. japonicum (inoculated). Soybean root hair cells were isolated at different time points (6hr, 12hr, 18hr, 24hr, 36hr, 48hr) after treatment. For each time point and condition, 3 or 4 independent biological replicates were produced.