Project description:adt06-04_mirna_nitrogen - mirna_nitrogen - Nitrogen starvation and re-supply. - To discover miRNA implied following a deficiency out of nitrogen and after reinduction.
Project description:adt06-04_mirna_nitrogen - mirna_nitrogen - Nitrogen starvation and re-supply. - To discover miRNA implied following a deficiency out of nitrogen and after reinduction. 6 dye-swap - time course
Project description:gnp3-b4_nitrogen_starvation - nitrogen starvation and re-supply - What are the transcriptomic short- and long-term plant responses to nitrogen starvation and nitrogen re-supply? - WS Arabidopsis ecotype were grown on 6mM nitrate as sole nitrogen source during 35 days under short days . At T0, plants were then starved for nitrate for 10 days and root and shoot samples were harvested separately 2 and 10 days after treatment (T2, T10). Then, nitrate (6 mM) was re-supplied for 1 and 24 hours (T+1, T+24). Keywords: time course
Project description:Plants aquire nitrogen from the soil, most commonly in the form of either nitrate or ammonium. Unlike ammonium, nitrate must be reduced (with NADH and ferredoxin as electron donors) prior to assimilation. Thus, nitrate nutrition imposes a substantially greater energetic cost than ammonium nutrition. Our goal was to compare the transcriptomes of nitrate-supplied and ammonium-supplied plants, with a particular interest in characterizing the differences in redox metabolism elicited by different forms of inorganic nitrogen. We used microarrays to compare the short-term transcriptional response to either nitrogen supply or ammonium supply in Arabidopsis roots. Genes upregulated or downregulated by nitrate only, ammonium only, or both ammonium and nitrate were identified and analyzed.
Project description:Plants aquire nitrogen from the soil, most commonly in the form of either nitrate or ammonium. Unlike ammonium, nitrate must be reduced (with NADH and ferredoxin as electron donors) prior to assimilation. Thus, nitrate nutrition imposes a substantially greater energetic cost than ammonium nutrition. Our goal was to compare the transcriptomes of nitrate-supplied and ammonium-supplied plants, with a particular interest in characterizing the differences in redox metabolism elicited by different forms of inorganic nitrogen. We used microarrays to compare the short-term transcriptional response to either nitrogen supply or ammonium supply in Arabidopsis roots. Genes upregulated or downregulated by nitrate only, ammonium only, or both ammonium and nitrate were identified and analyzed. Arabidopsis thaliana (Col-0) plants were grown hydroponically until they reached growth stage 5.10. They were then transferred to a nitrogen-free medium for 26 hr and then supplied with 1 mM nitrate or 1 mM ammonium. RNA isolation (and subsequent microarray analysis) was performed on root tissue isolated just before nitrogen supply (time 0) and at 1.5 hr and 8 hr after nitrogen supply (1.5 hr nitrate, 8 hr nitrate, 1.5 hr ammonium, 8 hr ammonium).
Project description:In comparison with provision of either ammonium or nitrate alone, simultaneously supplying both forms of N results in superior growth and yield for the majority of plants including rice. Using a rice 22K oligo-array, we performed transcriptome analysis to identify genes of rice (Oryza sativa L. ssp. japonica) responsive to change of N-supply forms and N-starvation. Using the supply of ammonium nitrate (one to one molar ratio) as control, the total number of root genes that were equal or more than two fold up- or down- regulated was 445, 324, and 781 by upon supply of either ammonium or nitrate or continuous N starvation, respectively for 96 h. In the shoot the equivalent numbers were much smaller only 32, 58, and 165, respectively. Clustering of the rice genes associated with different environmental stresses revealed substantial organ specificity of the root and shoot to N starvation, and also to the N supply form. Genes encoding transporters for ammonium and nitrate, nitrate reductase, glutamate dehydrogenase, and aspartate amino transferase, showed great response to change of the N supply form, especially to N starvation. Some of the genes involved in chlorophyll metabolism, carbon fixation and assimilation, were enhanced by ammonium supply only, but significantly suppressed by N-starvation. In the shoot there was increased expression of more general stress genes under nitrate when compared to ammonium nutrition. In the root the reverse situation was true with more apparent stress under ammonium nutrition. The microarray approach has revealed new levels of complexity in the response of rice to the form of N supply. Keywords: Rice; root; shoot; nitrogen starvation; nitrogen form; ammonium; nitrate; gene expression
