Project description:mutants in the stalk biogenesis and sigma-54 pathways deletion mutants of each component were compared to wild type, with all strains grown to mid-log phase as mixed populations
Project description:Analyses of the Wild type and the sigma 54 mutant strain NZ7306 with and without peroxide treatment: A Lactobacillus plantarum strain with a deletion in the alternative sigma factor 54 (?54) encoding gene rpoN, displayed a 100 fold higher sensitivity to peroxide as compared to its parental strain. This feature could be due to ?54-dependent regulation of genes involved in peroxide stress response. However, transcriptome analyses of the wild type and the mutant strain during peroxide exposure did not support such a role for ?54. Subsequent experiments revealed that the impaired expression of the mannose PTS operon in the rpoN mutant caused the observed increased peroxide sensitivity. Keywords: genetic modification
Project description:Pearl millet is a major cereal crop that feeds more than 90 million people worldwide in arid and semi-arid regions. The stalk phenotypes of Poaceous grasses are critical for their productivity and stress tolerance, however, the molecular mechanisms governing stalk development in pearl millet remained to be deciphered. In this study, we spatiotemporally measured 19 transcriptomes for stalk internodes of four different early developmental stages. Data analysis of the transcriptomes defined 4 developmental zones on the stalks and identified 12 specific gene sets with specific expression patterns across the zones. Using weighted gene co-expression network analysis (WGCNA), we found that 2 co-expression modules together with candidate genes were involved in stalk elongation and thickening of pearl millet. Among the elongation-related candidate genes, we established by SELEX that a MYB-family transcription factor PMF7G02448 can bind to the promoters of three cell wall synthases genes (CesAs). In summary, these findings provide insights into stalk development and offer potential targets for future genetic improvement of pearl millet.
Project description:Fusarium graminearum can infect maize stalk causing Gibberella stalk rot. We want to know the whole genome wide gene profiling when infecting maize stalk.
Project description:To determine the genes in addition to fimA regulated by sigma 54 by analysing the gene expression profiles of an rpoN mutant compared to the D. nodosus wild-type strain. Keywords: genetic modification
Project description:Fusarium graminearum can infect maize stalk causing Gibberella stalk rot. We want to know the whole genome wide gene profiling when infecting maize stalk. Using lasr capture microdisecction, we captured 8 time points infecting hyphae samples for maize stalk and after two-round amplification, we hybrid the aRNA to Affymetrix array.
Project description:Sugarcane accumulates high concentrations of sucrose in the mature stalk, with numerous physiological processes in maturing stalk tissue both directly and indirectly involved. A considerable portion of carbohydrate metabolism is also devoted to cell wall synthesis and fibre production. Previously, we have identified differentially expressed transcripts correlated with sucrose accumulation and fibre production in various internodes of the sugarcane stalk. In this study, we have examined tissue-specific expression patterns to further explore gene pathways responsible for sucrose accumulation and fibre synthesis. We performed large-scale expression profiling of storage parenchyma, vascular bundles and rind dissected from a maturing stalk internode from field-grown commercial sugarcane harvested at 11 months of age. We identified 10 cellulose synthase subunit genes in sugarcane and examined significant differences in the expression of their corresponding transcripts and those of several sugar transporters between the different tissues. These were further correlated with differential expression patterns for transcripts of specific COBRA-like proteins and other proteins with acknowledged roles in cell wall metabolism. We found that the sugar transporters ShPST2a, ShPST2b and ShSUT4 were significantly up-regulated in storage parenchyma while ShSUT1 was up-regulated in vascular bundles. Two co-ordinately expressed groups of cell wall related transcripts were also identified. One group which is associated with primary cell wall synthesis (ShCesA1, ShCesA7, ShCesA9 and Shbk2l3) was up-regulated in parenchyma. The other group which is associated with secondary cell wall synthesis (ShCesA10, ShCesA11, ShCesA12 and Shbk-2) was up-regulated in rind. We also report an unexpected paucity in differential expression of cell wall-related genes in vascular bundles. Our results indicate that there is spatial separation for elevated expression of these important targets in both sucrose accumulation and cell wall synthesis, allowing for increased clarity in our understanding of sucrose transport and fibre synthesis in sugarcane.