Project description:The present dataset is composed of Lotus japonicus root exudate samples under different nitrogen states: starved (no nitrogen), inorganic N (KNO3), symbiotic N (inoculation with M. loti), and inorganic/symbiotic (KNO3 + M. loti). The samples were analyzed by ultra-high-performance liquid chromatography (UHPLC) coupled to a quadrupole time-of-flight mass spectrometer (qToF MS, Bruker Compact) with electrospray ionization.
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:Lotus japonicus is a model legume broadly used to study transcriptome regulation under different stress conditions and microorganism interaction. Understanding how this model plant respond gainst alkaline stress will certainly help to develop more tolerant cultivars in economically important Lotus species as well as in other legumes. In order to uncover the most important response mechanisms activated during alkaline stress, we explored by microarray analysis the transcriptome regulation occurring in the phenotypically contrasting ecotypes MG-20 and Gifu B-129 of L. japonicus after 21 days of alkaline stress.
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.
Project description:To investigate the function of NAC094 in vivo, we overexpressed NAC094 in the infected cells of nodules using an L. japonicus Lb2 expression cassette. To this end, we used a GUS overexpression construct as control and analysed stably transformed plants to detect symbiotic phenotypes. Results show that overexpression of NAC094 causes premature senescence of nodules. To identify the mechanism by which NAC094 regulates nodule senescence, we performed a transcriptome profiling analysis of nodules at 3 wpi. Around 13,850 differentially expressed genes (DEGs) were identified by comparing NAC-OE with control nodules (Log2FC > 1, FDR < 0.05). Of these, 7,516 were up-regulated (NAC-OE-UP) and 6,334 were down-regulated (NAC-OE-DOWN).
Project description:Lotus japonicus is a model legume broadly used to study transcriptome regulation under different stress conditions and microorganism interaction. Understanding how this model plant protects itself against pathogens will certainly help to develop more tolerant cultivars in economically important Lotus species as well as in other legumes. In order to uncover the most important defense mechanisms activated upon bacterial attack, we explored by microarray analysis the transcriptome regulation occurring in the phenotypically contrasting ecotypes MG-20 and Gifu B-129 of L. japonicus after inoculation with the non-pathogenic strain Pseudomonas syringae DC3000 pv. tomato.
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:Drought is one of the major environmental factors limiting biomass and seed yield production in agriculture. In this research we focused on plants from Fabaceae family, which have a unique ability for establishment of symbiosis with nitrogen-fixing bacteria, and are relatively susceptible to water limitation. We present the changes in nitrogenase activity and global gene expression occurring in Medicago truncatula and Lotus japonicus root nodules during water deficit. Our results prove a decrease in the efficiency of nitrogen fixation as well as extensive changes in plant and bacterial transcriptomes shortly after watering cessation. We show for the first time that not only symbiotic plant component, but also Sinorhizobium meliloti and Mesorhizobium loti bacteria residing in the root nodules of M. truncatula and L. japonicus, respectively, adjust their gene expression in response to water shortage. Although our results demonstrate that both M. truncatula and L. japonicus root nodules are susceptible to water deprivation, they indicate significant differences in plant and bacterial response to drought between tested species, which may be related to various type of root nodules formed by these species.