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.
Project description:Legumes interact with nodulating bacteria that convert atmospheric nitrogen into ammonia for plant use. This nitrogen fixation takes place within root nodules that form after infection of root hairs by compatible rhizobia. Using cDNA microarrays, we monitored gene expression in soybean (Glycine max) inoculated with the nodulating bacterium Bradyrhizobium japonicum 4, 8, and 16 days after inoculation (dai), time points that coincided with nodule development and the onset of nitrogen fixation. This experiment identified several thousand genes that were differentially expressed in response to B. japonicum inoculation. Expression of 27 genes was analyzed by qRT-PCR and their expression patterns mimicked the microarray results confirming integrity of analyses. The microarray results suggest that B. japonicum reduces plant defense responses during nodule development. In addition, the data revealed a high level of regulatory complexity (transcriptional, post-transcriptional, translational, post-translational) that is likely essential for development of the symbiosis and adjustment to an altered nutritional status. Keywords = symbiosis Keywords = nodulation Keywords = rhizobium Keywords = defense Keywords = ANOVA Keywords = plant Keywords: nodulating vs not nodulating
Project description:Legumes interact with nodulating bacteria that convert atmospheric nitrogen into ammonia for plant use. This nitrogen fixation takes place within root nodules that form after infection of root hairs by compatible rhizobia. Using cDNA microarrays, we monitored gene expression in soybean (Glycine max) inoculated with the nodulating bacterium Bradyrhizobium japonicum 4, 8, and 16 days after inoculation (dai), time points that coincided with nodule development and the onset of nitrogen fixation. This experiment identified several thousand genes that were differentially expressed in response to B. japonicum inoculation. Expression of 27 genes was analyzed by qRT-PCR and their expression patterns mimicked the microarray results confirming integrity of analyses. The microarray results suggest that B. japonicum reduces plant defense responses during nodule development. In addition, the data revealed a high level of regulatory complexity (transcriptional, post-transcriptional, translational, post-translational) that is likely essential for development of the symbiosis and adjustment to an altered nutritional status. Keywords = symbiosis Keywords = nodulation Keywords = rhizobium Keywords = defense Keywords = ANOVA Keywords = plant loop design, 7 samples, 7 comparison, 2 technical repeats including dye swaps, 4 biological repeats
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.
Project description:Analysis of a mutant in the Bradyrhizobium japonicum response regulator RegR. RegR is known to control expression of the gene encoding the key regulator of nitrogen fixation NifA. This study provides insights into the RegR regulon under free-living conditions and during symbiosis. Cells of the regR mutant and the wild type were grown to mid-exponential phase in full medium (PSY) under different oxygen conditions (aerobic and microaerobic) in culture. Nodules from soybean plant infected with the regR mutant or the wild type were collected 13 and 21 days post inoculation To determine genes under control of RegR during symbiosis. This study includes also the samples GSM210238 to GSM210286. Keywords: genetic modification, time course, growth conditions