Project description:This SuperSeries is composed of the following subset Series: GSE30091: Expression analysis of the effect of protoplasting and sorting in roots exposed to low pH GSE30095: Expression analysis of root cell types after treatment with low pH GSE30096: Expression analysis of developmental stages of Arabidopsis roots exposed to low pH GSE30097: Time-course expression analysis of the low pH (pH 4.6) response in Arabidopsis whole roots GSE30098: Expression analysis time-course of Arabidopsis roots to sulfur deficiency GSE30099: Expression analysis of root cell types after treatment with sulfur deficient media GSE30100: Expression analysis of developmental stages of Arabidopsis roots exposed to sulfur deficient media GSE30104: Genome-wide identification of SCARECROW (SCR) direct targets using a custom Agilent promoter array Refer to individual Series
Project description:Cell-type specific transcriptional profiles were generated by FACS (Fluorescence Activated Cell Sorting) sorting of roots that express cell-type specific GFP-reporters. Five different GFP-reporter lines were used. FACS cell populations were isolated from roots grown under standard pH (pH 5.7) or roots that had been transfered to low pH (pH 4.6) media for 24 hours. Stress responses in plants are tightly coordinated with developmental processes, but the interaction between these pathways is poorly understood. Here we use genome-wide assays at high spatial and temporal resolution to understand the processes that lnk development and stress in the Arabidopsis root. Our meta-analysis finds little evidence for a universal stress response. Common stress responses appear to exists and, analagous to animal systems, many of them show cell-type specificity, suggesting a convergent evolutionary theme in multicellular organisms. Common stress responses may be mediated by cell identity regulators, as mutations in these genes resulted in altered responses to stress. Our results reveal surprising linkages between stress and development at cellular resolution, and show the power of multiple genome-wide datasets to elucidate biological processes.
Project description:Cell-type specific transcriptional profiles were generated by FACS (Fluorescence Activated Cell Sorting) sorting of roots that express cell-type specific GFP-reporters. Five different GFP-reporter lines were used. FACS cell populations were isolated from roots grown under standard pH (pH 5.7) or roots that had been transfered to low pH (pH 4.6) media for 24 hours. Stress responses in plants are tightly coordinated with developmental processes, but the interaction between these pathways is poorly understood. Here we use genome-wide assays at high spatial and temporal resolution to understand the processes that lnk development and stress in the Arabidopsis root. Our meta-analysis finds little evidence for a universal stress response. Common stress responses appear to exists and, analagous to animal systems, many of them show cell-type specificity, suggesting a convergent evolutionary theme in multicellular organisms. Common stress responses may be mediated by cell identity regulators, as mutations in these genes resulted in altered responses to stress. Our results reveal surprising linkages between stress and development at cellular resolution, and show the power of multiple genome-wide datasets to elucidate biological processes. 3 replicates for each of 5 cell types for low pH and standard pH (30 samples total).
Project description:Aluminum (Al) is the most common metal in the Earth’s crust and Al toxicity is considered to be the most harmful abiotic stress in acidic soils that today comprise more than 50% of the world’s arable lands. The first symptom of Al toxicity is the reduction of root growth, resulting in decreased water and nutrients uptake, plant growth retardation, and finally, yield reduction. Barley (Hordeum vulgare L.), which is the fourth cereal crop in regards to cultivation area and production tonnage, belongs to crops most sensitive to toxic aluminum ions in low pH soils. We present the RNA-seq transcriptome analysis of root meristems of barley seedlings grown in hydroponics at optimal pH (6.0), low pH (4.0), and low pH with Al (10 µM of bioavailable Al3+ ions). Two independent experiments were conducted: with short-term (24 h) and long-term (7 days) Al treatment. Interestingly, in the short-term experiment, more genes were differentially expressed between root meristems grown at pH=6.0 and pH=4.0, than between those grown at pH=4.0 with and without Al treatment. The upregulated genes that were overrepresented at conditions of low pH, compared to optimal pH, were associated with response to oxidative stress, cell wall organization, and iron ion binding. Among genes downregulated by low pH were mainly those related to chromatin organization. These results show that low pH itself is a severe stress for barley plants. Among genes upregulated by short Al treatment, overrepresented were those related to response to stress condition and calcium ion binding. After 7 days of hydroponics, the number of DEGs between hydroponics at pH=4.0 and 6.0 were still high but lower than in the short-term experiment, which suggests that plants partially adapted to the low pH. Interestingly, 7 day Al treatment caused massive changes in the transcriptome profile compared to the condition of low pH alone. Over 4 000 genes were upregulated and almost 2 000 genes were downregulated by long-term Al stress. These DEGs were related to e.g. stress response, cell wall development and metal ion transport. Based on our results we can assume that both, Al3+ ions and low pH are harmful to barley plants.Additionally, we phenotyped in detail the root system of barley seedlings grown in the same hydroponic conditions for 7 days at pH=6.0, pH=4.0, and pH=4.0 with Al. The results correspond to transcriptomic data and show that low pH itself is a stress facor that causes a significant reduction of root growth and the addition of aluminum further increases this reduction. It should be underlined that in the acidic arable lands, plants are exposed simultaneously to both of these stresses (low pH and Al), as Al becomes soluble at pH below 5.5. The presented transcriptome analysis may help to find potential targets for breeding barley plants more tolerant to such conditions.