Project description:This SuperSeries is composed of the following subset Series: GSE8570: Comparison of B. japonicum mutant strain Δ901 induced versus wild type uninduced GSE8571: Comparison of B. japonicum 110spc4 (wild type) induced versus uninduced GSE8572: Comparison of B. japonicum mutant strain 613 induced versus wild type uninduced Keywords: SuperSeries Refer to individual Series
Project description:part of GSE8478: Genome-wide transcript analysis of Bradyrhizobium japonicum bacteroids in soybean root nodules This SuperSeries is composed of the SubSeries listed below.
Project description:Expression data from B. japonicum stress response; aerobic treatment of B. japoncium culture under different stress conditons; pH stress (8 and 4; 4 h); salt stress (80 mM NaCl; 4 h); heat shock (43 °C; 15 min) and temperature stress (35.2 °C; 48 h); as reference wildtype without treatment (AG media; pH 6.9; without NaCl; 28 °C) was used heat shock data were verified by using rpoH-mutant strains B. japonicum 5009; B. japonicum 5032 and B. japonicum 09-32 as described in Narberhaus et al. 1997
Project description:To dissect differences in gene expression profile of soybean roots inoculated with wild-type and type III secretion mutant rhizobia, we have employed microarray analysis. Seeds of soybeans (Glycine max L. cv. Enrei and its non-nodulating line En1282) were surface-sterilized and germinated at 25 °C for 2 days and were transferred to a plant box (CUL-JAR300; Iwaki, Tokyo, Japan) containing sterile vermiculite watered with B&D nitrogen-free medium (Broughton and Dilworth 1971). One day after transplant, each seedling was inoculated with Bradyrhizobium elkanii USDA61, its type III secretion mutant BerhcJ or sterilized water (mock treatment). Plants were cultivated in a growth chamber at 25°C and 70% humidity with a daytime of 16 h followed by a nighttime of 8 h. To determine the gene expression, RNA was extracted from the roots 8 days after inoculation.
Project description:To dissect differences in gene expression profile of soybean roots inoculated with wild-type and type III secretion mutant rhizobia, we have employed microarray analysis. Seeds of soybean (Glycine max L. cv. BARC-2 (Rj4/Rj4)) were surface-sterilized and germinated at 25 °C for 2 days and were transferred to the seed pack (Seed Pack; Daiki rika Kogyo Co., Ltd., Shiga, Japan) watered with B&D nitrogen-free medium (Broughton and Dilworth 1971). One day after transplant, each seedling was inoculated with Bradyrhizobium elkanii USDA61 or its type III secretion mutant BErhcJ. Plants were cultivated in a growth chamber at 25°C and 70% humidity with a daytime of 16 h followed by a nighttime of 8 h. To determine the gene expression, RNA was extracted from the roots 2 and 4 days after inoculation.
Project description:BACKGROUND:The soybean-Bradyrhizobium symbiosis can be highly efficient in fixing nitrogen, but few genomic sequences of elite inoculant strains are available. Here we contribute with information on the genomes of two commercial strains that are broadly applied to soybean crops in the tropics. B. japonicum CPAC 15 (=SEMIA 5079) is outstanding in its saprophytic capacity and competitiveness, whereas B. diazoefficiens CPAC 7 (=SEMIA 5080) is known for its high efficiency in fixing nitrogen. Both are well adapted to tropical soils. The genomes of CPAC 15 and CPAC 7 were compared to each other and also to those of B. japonicum USDA 6T and B. diazoefficiens USDA 110T. RESULTS:Differences in genome size were found between species, with B. japonicum having larger genomes than B. diazoefficiens. Although most of the four genomes were syntenic, genome rearrangements within and between species were observed, including events in the symbiosis island. In addition to the symbiotic region, several genomic islands were identified. Altogether, these features must confer high genomic plasticity that might explain adaptation and differences in symbiotic performance. It was not possible to attribute known functions to half of the predicted genes. About 10% of the genomes was composed of exclusive genes of each strain, but up to 98% of them were of unknown function or coded for mobile genetic elements. In CPAC 15, more genes were associated with secondary metabolites, nutrient transport, iron-acquisition and IAA metabolism, potentially correlated with higher saprophytic capacity and competitiveness than seen with CPAC 7. In CPAC 7, more genes were related to the metabolism of amino acids and hydrogen uptake, potentially correlated with higher efficiency of nitrogen fixation than seen with CPAC 15. CONCLUSIONS:Several differences and similarities detected between the two elite soybean-inoculant strains and between the two species of Bradyrhizobium provide new insights into adaptation to tropical soils, efficiency of N2 fixation, nodulation and competitiveness.
Project description:In a survey of DNA fingerprints of indigenous Bradyrhizobium japonicum with the species-specific repeated sequences RS alpha and RS beta, 21 isolates from three field sites showed numerous RS-specific hybridization bands. The isolates were designated highly reiterated sequence-possessing (HRS) isolates, and their DNA hybridization profiles were easily distinguished from the normal patterns. Some HRS isolates from two field sites possessed extremely high numbers of RS alpha copies, ranging from 86 to 175 (average, 128), and showed shifts and duplications of nif- and hup-specific hybridization bands. The HRS isolates exhibited slower growth than normal isolates, although no difference in symbiotic properties was detected between the HRS and normal isolates. Nucleotide sequence analysis of 16S rRNA genes showed that HRS isolates were strains of B. japonicum. There was no difference in the spectra of serological and hydrogenase groupings of normal and HRS isolates. Some HRS isolates possessed a tandem repeat RS alpha dimer that is similar to the structure of (IS30)2, which was shown to cause a burst of transpositional rearrangements in Escherichia coli. The results suggest that HRS isolates are derived from normal isolates in individual fields by genome rearrangements that may be mediated by insertion sequences such as RS alpha.
Project description:This SuperSeries is composed of the following subset Series: GSE10295: Bj_Heterotrophy vs. Arabinose supplemented chemoautotrophy GSE10296: Bj_Heterotrophy vs. Chemoautotrophy GSE10298: Bj_Chemoautotrophy vs. Arabinose supplemented chemoautotrophy Refer to individual Series