Project description:To find out the genotype specific differentially expressed genes in response to N source Two contrasting Indica rice genotypes namely, Nidhi and Panvel 1 were used. Arnon Hoagland medium with either nitrate or urea were used as fertilizer sources. Two N doses, normal (15 mM of N) was used as control while low (1.5mM of N) was used as test.
Project description:Although urea is the most used nitrogen fertilizer worldwide, little is known on the capacity of crop plants to use urea per se as a nitrogen source for development and growth. To date, the molecular and physiological bases of its transport have been investigated only in a limited number of species. In particular, up to date only one study reported the transcriptomic modulation induced by urea treatment in the model plant Arabidopsis (MM-CM-)rigout et al., 2008 doi: 10.1104/pp.108.119339). In maize, one of crops using huge amount of urea, only a physiological characterization of uptake and assimilation of the N-source has been conducted. General aim of the present work was the comprehension of the molecular basis of urea uptake and assimilation in maize plants, using a transcriptomic approach. In addition, the work focused on the possible interactions between the two main N-sources, conceivably occurring concomitantly in the soil, urea and nitrate. 5 dd-old maize plants were treated for 8 hours with nutrient solution containing nitrogen in form of urea; nitrate; urea and nitrate; or not exposed to any form of nitrogen. Three different biological replicates were used for each sample repeating the experiment three times. All samples were obtained pooling roots of six plants.
Project description:Purpose: RNA-seq technology was used to profile the transcriptome of a Chinese strain of A. anophagefferens that was grown on urea, nitrate, and a mixture of urea and nitrate, and that was under N-replete, limited and recovery conditions to understand the molecular mechanisms that underlie nitrate and urea utilization. Methods: mRNA profiles of Aureococcus anophagefferens that was grown on urea, nitrate, and a mixture of urea and nitrate, and that was under N-replete, limited and recovery conditions were generated by deep sequencing using Illumina HiSeq 2000. The sequence reads that passed quality filters were analyzed by aligning to reference genome and transcript using SOAPaligner/SOAP2 (version 2.21). Results: Deconvolution and filtering of raw reads yielded a mean of 6,938,798 reads (range: 6,539,842 to 7,242,083 reads) per individual RNA-seq library (Table 1). Subsequent alignment of the clean reads to the A. anophagefferens reference genome yielded a mean of 5,852,408 reads (84.3%) for each sample that mapped to at least one location in the A. anophagefferens genome. However, of these mapped reads, only 47.4 to 50.9% of the total reads were mapped to the reference transcript for each sample (Table 2). In A. anophagefferens grown on three different N sources, 9148 to 9526 genes were detected for each sample. A comparison of gene expression among the three N sources was performed. 322 differentially expressed genes were detected between nitrate-grown and urea-grown cells, 237 between nitrate-grown and mixture N-grown cells and 29 between urea-grown and mixture N-grown cells. Fewer differentially expressed genes between urea-grown and mixture N-grown cells were identified, which further suggested the preferred utilization of cells for urea in media with mixture N. For nitrogen-limited and recovery experiments, 707 genes were up-regulated significantly, and 766 were down-regulated significantly in N-depleted cells relative to N-replete cells. N-depleted cells exhibited a broad transcriptional response to nitrogen re-addition, with 681 genes up-regulated and 874 genes down-regulated in urea recovery cells, and 312 genes up-regulated and 688 genes down-regulated in nitrate recovery cells. Conclusions: We noted that transcripts upregulated by nitrate and N-limitation included those encoding proteins involved in amino acid, nucleotide and aminosugar transport, degradation of amides and cyanates, and nitrate assimilation pathway. The data suggest that A. anophagefferens possesses an ability to utilize a variety of dissolved organic nitrogen. Moreover, transcripts for synthesis of proteins, glutamate-derived amino acids, spermines and sterols were upregulated by urea. Transcripts encoding key enzymes that are involved in the ornithine-urea and TCA cycles were differentially regulated by urea and nitrogen concentration, which suggests that the OUC may be linked to the TCA cycle and involved in reallocation of intracellular carbon and nitrogen. These genes regulated by urea may be crucial for the rapid proliferation of A. anophagefferens when urea is provided as the N source.
Project description:Purpose: RNA-seq technology was used to profile the transcriptome of a Chinese strain of A. anophagefferens that was grown on urea, nitrate, and a mixture of urea and nitrate, and that was under N-replete, limited and recovery conditions to understand the molecular mechanisms that underlie nitrate and urea utilization. Methods: mRNA profiles of Aureococcus anophagefferens that was grown on urea, nitrate, and a mixture of urea and nitrate, and that was under N-replete, limited and recovery conditions were generated by deep sequencing using Illumina HiSeq 2000. The sequence reads that passed quality filters were analyzed by aligning to reference genome and transcript using SOAPaligner/SOAP2 (version 2.21). Results: Deconvolution and filtering of raw reads yielded a mean of 6,938,798 reads (range: 6,539,842 to 7,242,083 reads) per individual RNA-seq library (Table 1). Subsequent alignment of the clean reads to the A. anophagefferens reference genome yielded a mean of 5,852,408 reads (84.3%) for each sample that mapped to at least one location in the A. anophagefferens genome. However, of these mapped reads, only 47.4 to 50.9% of the total reads were mapped to the reference transcript for each sample (Table 2). In A. anophagefferens grown on three different N sources, 9148 to 9526 genes were detected for each sample. A comparison of gene expression among the three N sources was performed. 322 differentially expressed genes were detected between nitrate-grown and urea-grown cells, 237 between nitrate-grown and mixture N-grown cells and 29 between urea-grown and mixture N-grown cells. Fewer differentially expressed genes between urea-grown and mixture N-grown cells were identified, which further suggested the preferred utilization of cells for urea in media with mixture N. For nitrogen-limited and recovery experiments, 707 genes were up-regulated significantly, and 766 were down-regulated significantly in N-depleted cells relative to N-replete cells. N-depleted cells exhibited a broad transcriptional response to nitrogen re-addition, with 681 genes up-regulated and 874 genes down-regulated in urea recovery cells, and 312 genes up-regulated and 688 genes down-regulated in nitrate recovery cells. Conclusions: We noted that transcripts upregulated by nitrate and N-limitation included those encoding proteins involved in amino acid, nucleotide and aminosugar transport, degradation of amides and cyanates, and nitrate assimilation pathway. The data suggest that A. anophagefferens possesses an ability to utilize a variety of dissolved organic nitrogen. Moreover, transcripts for synthesis of proteins, glutamate-derived amino acids, spermines and sterols were upregulated by urea. Transcripts encoding key enzymes that are involved in the ornithine-urea and TCA cycles were differentially regulated by urea and nitrogen concentration, which suggests that the OUC may be linked to the TCA cycle and involved in reallocation of intracellular carbon and nitrogen. These genes regulated by urea may be crucial for the rapid proliferation of A. anophagefferens when urea is provided as the N source. Seven mRNA samples for Aureococcus anophagefferens were sequencd using Illumina HiSeqTM 2000, including three samples that was grown on urea, nitrate, and a mixture of urea and nitrate, and four samples that was under N-replete, limited and recovery conditions
Project description:Although urea is the most used nitrogen fertilizer worldwide, little is known on the capacity of crop plants to use urea per se as a nitrogen source for development and growth. To date, the molecular and physiological bases of its transport have been investigated only in a limited number of species. In particular, up to date only one study reported the transcriptomic modulation induced by urea treatment in the model plant Arabidopsis (Mérigout et al., 2008 doi: 10.1104/pp.108.119339). In maize, one of crops using huge amount of urea, only a physiological characterization of uptake and assimilation of the N-source has been conducted. General aim of the present work was the comprehension of the molecular basis of urea uptake and assimilation in maize plants, using a transcriptomic approach. In addition, the work focused on the possible interactions between the two main N-sources, conceivably occurring concomitantly in the soil, urea and nitrate.
Project description:PII signal transduction proteins are widely spread among all domains of life where they regulate a multitude of carbon and nitrogen metabolism related processes. Non-diazotrophic cyanobacteria can utilize a high variety of organic and inorganic nitrogen sources. In recent years, several physiological studies indicated an involvement of the cyanobacterial PII protein in regulation of ammonium, nitrate/nitrite and cyanate uptake. However, direct interaction of PII has not been demonstrated so far. In this study, we used biochemical, molecular genetic and physiological approaches to demonstrate that PII regulates all relevant nitrogen uptake systems in Synechocystis sp. strain PCC 6803: PII controls ammonium uptake by interacting with the Amt1 ammonium permease, probably similar to the known regulation of E. coli ammonium permease AmtB by the PII homologue GlnK. We could further clarify that PII mediates the ammonium- and dark-induced inhibition of nitrate uptake by interacting with the NrtC and NrtD subunits of the nitrate/nitrite transporter NrtABCD. We further identified the ABC-type urea transporter UrtABCDE as novel PII target. PII interacts with the UrtE subunit without involving the standard interaction surface of PII interactions. The deregulation of urea uptake in a PII deletion mutant causes ammonium excretion when urea is provided as nitrogen source. Furthermore, the urea hydrolyzing urease enzyme complex appears to be coupled to urea uptake. Overall, this study underlines the great importance of the PII signal transduction protein in the regulation of nitrogen utilization in cyanobacteria.
Project description:To identify the differetially expressed genes under nitrate stress, RNA-seq was performed using total RNA extracted from root and seedling tissues from plants were grown in both low (0 mM) and high (100 mM) nitrate conditions. The analysis was performed in duplicates and the reads were mapped to rice (IRGSP-1) genome.
Project description:To identify the differetially expressed sRNAs under nitrate stress, sRNA-seq was performed using total RNA extracted from root and seedling tissues from plants were grown in both low (0 mM) and high (100 mM) nitrate conditions. The analysis was performed in duplicates and the reads were processed and analysed using UEA sRNA workbench.
Project description:MADS27 was differetially expressed during nitrate stress in roots of rice plant. In order to further verify the effect of MADS27 overexpression in rice root development, RNA-seq analysis was performed on plants overexpressing MADS27.
Project description:Nitrate and other nitrogen metabolites can act as signals that regulate global gene expression in plants. Adaptive changes in plant morphology and physiology triggered by changes in nitrate availability are partly explained by these changes in gene expression. Despite several genome-wide efforts to identify nitrate-regulated genes, no comprehensive study of the Arabidopsis root transcriptome under contrasting nitrate conditions has been carried out. In this work, we employed the Illumina high throughput sequencing technology to perform an integrated analysis of the poly-A+ enriched and the small RNA fractions of the Arabidopsis thaliana root transcriptome in response to nitrate treatments. Our sequencing strategy identified new nitrate-regulated genes including 40 genes not represented in the ATH1 Affymetrix GeneChip, a novel nitrate-responsive antisense transcript and a new nitrate responsive miRNA/TARGET module consisting of a novel microRNA, miR5640 and its target, AtPPC3. This nitrate-responsive miRNA/target module might be involved in controlling carbon flux to assimilate nitrate into amino acids, suggesting that microRNAs can have both developmental and metabolic functions in the nitrate response of Arabidopsis roots.