Project description:This experiment was annotated by TAIR (http://arabidopsis.org). This experiment studies the response of gene expression in roots of 25-35 day old plants grown on hydroponics after 6, 48 and 96 hours of potassium starvation. RNA from roots was extracted after transfer to control (control) or potassium free nutrient solution respectively (starvation). Experimenter name = Julian Schroeder; Experimenter phone = 619-534-7759; Experimenter fax = 619-534-7108; Experimenter department = J Schroeder Laboratory; Experimenter institute = University of California-San Diego; Experimenter address = Biology Department; Experimenter address = University of California-San Diego; Experimenter address = La Jolla; Experimenter zip/postal_code = CA 92093-0116; Experimenter country = USA Experiment Overall Design: 4 samples were used in this experiment
Project description:This experiment was annotated by TAIR (http://arabidopsis.org). This experiment studies the response of gene expression in roots of 25-35 day old plants grown on hydroponics after 6, 48 and 96 hours of potassium starvation. RNA from roots was extracted after transfer to control (control) or potassium free nutrient solution respectively (starvation). Experimenter name = Julian Schroeder Experimenter phone = 619-534-7759 Experimenter fax = 619-534-7108 Experimenter department = J Schroeder Laboratory Experimenter institute = University of California-San Diego Experimenter address = Biology Department Experimenter address = University of California-San Diego Experimenter address = La Jolla Experimenter zip/postal_code = CA 92093-0116 Experimenter country = USA Keywords: time_series_design; growth_condition_design
Project description:In this study we investigated the transcriptional response of the yeast Saccharomyces cerevisiae to potassium starvation. To this end yeast cells were grown for 60 min in media without potassium or in media with a standard potassium concnetration (50 mM KCl). Using Serial Analysis of Gene Expression (SAGE)-tag sequencing the effect of potassium starvation on the transcriptome was determined.
Project description:Background: Over application of phosphate fertilizers in modern agriculture contaminates waterways and disrupts natural ecosystems. Nevertheless, this is a common practice among farmers, especially in developing countries as abundant fertilizers are believed to boost crop yields. The study of plant phosphate metabolism and its underlying genetic pathways is key to discovering methods of efficient fertilizer usage. The work presented here describes the first genome-wide resource on the molecular dynamics underpinning the response and recovery in roots and shoots of Arabidopsis thaliana to phosphate-starvation. Results: Genome-wide profiling revealed minimal overlap between root and shoot transcriptomes suggesting two independent phosphate-starvation regulons. Novel gene expression patterns were detected for over 1000 candidates and were classified as either initial, persistent, or latent responders. Comparative analysis to AtGenExpress identified novel cohorts of genes co-regulated across multiple stimuli. The hormone ABA displayed a dominant role in regulating many phosphate-responsive candidates. Analysis of co-regulation enabled the determination of primary versus redundant members of closely related gene families with respect to phosphate-starvation. Thus, among others, we show that PHO1 acts in shoot, whereas PHO1;H1 is likely the primary regulator in root. Conclusion: Our results uncover a much larger, staged responses to phosphate-starvation than previously described. To our knowledge, this work describes the highest resolution of genome-wide data on plant nutrient stress to date.
Project description:Coordinated distribution of Pi between roots and shoots is an important process that plants use to maintain Pi homeostasis. SHR (SHORT-ROOT) is well-characterized for its function in root radial patterning1-3. Here, we demonstrate a new role of SHR in controlling phosphate (Pi) allocation from roots to shoots by regulating PHOSPHATE1 (PHO1) in the root differentiation zone. We recovered a weak mutant allele of SHR in Arabidopsis which accumulates much less Pi in the shoot and shows constitutive Pi starvation response (PSR) under Pi-sufficient condition. Besides, Pi starvation suppresses SHR protein accumulation and releases its inhibition on the HD-ZIP Ⅲ transcription factor PHB. PHB accumulates and directly binds the promoter of PHO2 to upregulate its transcription, resulting in PHO1 degradation in the xylem-pole pericycle cells. Our findings reveal a previously unrecognized mechanism of how plants repress Pi translocation from roots to shoots in response to Pi starvation.
Project description:In this study we investigated the transcriptional response of the yeast Saccharomyces cerevisiae to potassium starvation. To this end yeast cells were grown for 60 min in media without potassium or in media with a standard potassium concnetration (50 mM KCl). Using Serial Analysis of Gene Expression (SAGE)-tag sequencing the effect of potassium starvation on the transcriptome was determined. 4 samples of cells grown in media without potassium and 4 samples of cells grown in the presence of potassium were analyzed.