Project description:The role of ANAC017 in leaf senescence was assessed by covering leaf 6-7 of 5 week old plants. Samples of Col-0, anac017 knock-out and two ANAC017 overexpression lines were compared of day 0, 1 and 3 of the timecourse. ANAC017 OE lines show accelerated senescence during this time.
Project description:Transcriptional profiling of Arabidopsis dark-induced senescence comparing wild type (Col-0) with pif quadruple (pif1/3/4/5) mutant. After synchronized germination, the plants were grown under continuous white light for 7 days and transferred to darkness for 2 days to induce senescence. Goal was to determine the effect of PIFs on transcriptomic regulation during dark-induced senescence.
Project description:Transcriptional profiling of Arabidopsis dark-induced senescence comparing wild type (Col-0) with pif quadruple (pif1/3/4/5) mutant. After synchronized germination, the plants were grown under continuous white light for 7 days and transferred to darkness for 2 days to induce senescence. Goal was to determine the effect of PIFs on transcriptomic regulation during dark-induced senescence. Two-condition experiment, wild type vs. pif quadruple mutant. Biological replicates: 3 wild type replicates, 3 mutant replicates.
Project description:A network model has been generated that describes the immediate gene expression cascade surrounding three similar but distinct NAC transcription factors that have roles to play in leaf senescence and in many stress responses in Arabidopsis. ANAC019, ANAC055 and ANAC072 belong to the same clade of NAC domain genes and have overlapping expression patterns. A combination of promoter DNA/protein interactions identified using yeast 1 hybrid analysis and modeling using gene expression time course data has been used to predict the regulatory network upstream of these genes. Similarities and divergence in regulation during a variety of stress responses are predicted by different combinations of upstream transcription factors binding and also by the modeling. Mutant analysis with potential upstream genes was used to test and confirm some of the predicted interactions.. Gene expression measurements in mutants of ANAC019 and ANAC055 at different times during leaf senescence have shown a distinctly different role for each of these genes. To assess mutant response to Dark Induced Senescence (DIS), leaf5 from transplanted rosettes, subjected to dark conditions, from Col-0, myb2 (genotype IM24) and myb108 (genotype BOS1) knockout plants, were photographically assessed for red/green ratio. When the average ratio for Col-0 samples was >0.8, leaf 5 for Col-0, myb2 and myb108 lines was harvested (4 biological replicates). The same sampling procedure was then performed on consecutive days to sample as senescence progressed. Analysis of expression differences between Col-0 and myb2 and Col-0 and myb108 under each condition, using dye swaps, was performed using the R Bioconductor package limmaGUI (Wettenhall and Smyth, 2004).
Project description:We used the flu mutant of Arabidopsis to detail gene expression in response to singlet oxygen. The conditional flu mutant of Arabidopsis accumulates excess protochlorophyllide in the dark within chloroplast membranes that upon illumination acts as a photosensitizer and generates singlet oxygen. Immediately after the release of singlet oxygen mature flu plants stop growing, whereas seedlings bleach and die. Within the first 30 min after the release of singlet oxygen rapid changes in nuclear gene expression occur. Distinct sets of genes were activated that were different from those induced by other reactive oxygen species, superoxide or hydrogen peroxide. Keywords: Time course