Project description:To gain insights into molecular mechanisms of tolerance to heat stress, we conducted a transcript profiling experiment to identify heat-responsive genes in contrasting peanut mini core accessions, either un-acclimated or acclimated to heat stress. Plants at reproductive stage were exposed to 28 °C (control), 45 °C for 15 d (un-acclimated) or 45 °C for 1 d followed by 7 d recovery and 15 d stress (acclimated). Two contrasting genotypes showing diverse response to stress were selected based on a bioassay involving chlorophyll fluorescence yield under elevated respiratory demand and membrane thermostability. Transcript profiling was performed using 8 x 15k custom oligo microarrays containing 15k peanut EST sequences. Gene enrichment analysis was performed using Blast2GO program and genes with homology to known proteins were categorized into detailed molecular functional groups. Majority of stress-responsive genes assigned to KEGG pathways belonged to starch, sucrose and galactose metabolism followed by aminoacid metabolism, and secondary metabolite biosynthesis. Differentially expressed transcripts from samples were validated in the samples from second year by quantitative real-time PCR. Transcripts of eight genes involved in terpenoid and flavanoid biosynthesis were induced after second and seventh day, respectively in leaves under heat stress. Metabolite analysis confirmed increases in metabolites of selected pathways under heat stress. The heat up-regulated genes in tolerant COC041 mini-core accession are potential candidate genes for engineering stress-tolerant peanuts and unraveling molecular mechanisms of peanut adaptation to heat stress. We used Agilent peanut microarrays to identify putative heat stress-responsive genes. Acclimated leaf tissues of the peanut genotypes COC041 (tolerant) and COC166 (susceptible) were used in the study. Three replications of microarray experiments were carried out by hybridizing the cRNA from different time points and stress conditions in a loop design on 8 x 15k microarray.

Project description:To gain insights into molecular mechanisms of tolerance to heat stress, we conducted a transcript profiling experiment to identify heat-responsive genes in contrasting peanut mini core accessions, either un-acclimated or acclimated to heat stress. Plants at reproductive stage were exposed to 28 °C (control), 45 °C for 15 d (un-acclimated) or 45 °C for 1 d followed by 7 d recovery and 15 d stress (acclimated). Two contrasting genotypes showing diverse response to stress were selected based on a bioassay involving chlorophyll fluorescence yield under elevated respiratory demand and membrane thermostability. Transcript profiling was performed using 4 x 44k custom oligo microarrays containing 22k peanut EST sequences. The microarray analysis identified 710 stress-induced and 770 stress-repressed putative heat-responsive transcripts in the tolerant genotype. Gene enrichment analysis was performed using Blast2GO program and genes with homology to known proteins were categorized into detailed molecular functional groups. Majority of stress-responsive genes assigned to KEGG pathways belonged to starch, sucrose and galactose metabolism followed by amino acid metabolism, and secondary metabolite biosynthesis. Differentially expressed transcripts from samples obtained from first year’s experiment were validated in the samples from second year by quantitative real-time PCR. Transcripts of eight genes involved in terpenoid and flavanoid biosynthesis were induced after second and seventh day, respectively, in leaves under heat stress. Metabolite analysis confirmed increases in metabolites of selected pathways under heat stress. The heat up-regulated genes in tolerant COC041 mini-core accession are potential candidate genes for engineering stress-tolerant peanuts and unraveling molecular mechanisms of peanut adaptation to heat stress. We used Agilent peanut microarrays to identify putative heat stress-responsive genes. Directly heat-stressed leaf tissues of the peanut genotypes COC041 (tolerant) and COC166 (susceptible) were used in the study. Three replications of microarray experiments were carried out by hybridizing the cRNA from different time points and stress conditions in a loop design on 4 x 44k microarray.

Project description:Abiotic stress causes disturbances in the cellular homeostasis. Re-adjustment of balance in carbon, nitrogen and phosphorus metabolism therefore plays a central role in stress adaptation. However, it is currently unknown which parts of the primary cell metabolism follow common patterns under different stress conditions and which represent specific responses. To address these questions, changes in transcriptome, metabolome and ionome were analyzed in maize source leaves from plants suffering low temperature, low nitrogen (N) and low phosphorus (P) stress. The selection of maize as study object provided data directly from an important crop species and the so far underexplored C4 metabolism. Growth retardation was comparable under all tested stress conditions. The only primary metabolic pathway responding similar to all stresses was nitrate assimilation, which was down-regulated. The largest group of commonly regulated transcripts followed the expression pattern: down under low temperature and low N, but up under low P. Several members of this transcript cluster could be connected to P metabolism and correlated negatively to different phosphate concentration in the leaf tissue. Accumulation of starch under low temperature and low N stress, but decrease in starch levels under low under low P conditions indicated that only low P treated leaves suffered carbon starvation. In conclusion, maize employs very different strategies for management of nitrogen and phosphorus metabolism under stress. While nitrate assimilation was regulated depending on demand by growth processes, phosphate concentrations changed depending on availability, thus building up reserves under excess conditions. Carbon and energy metabolism of the C4 maize leaves were particularly sensitive to P starvation. Responses of maize source leaves to low temperature, low nitrogen and low phosphorus conditions were tested in independent single-stress experiments. Seedlings were cultivated in pots containing nutrient-poor peat soil under the controlled conditions of a growth chamber. The plants were fertilized with modified Hoagland solutions, containing 15mM KNO3 and 0.5mM KH2PO4 for control conditions; for low N and low P treatment, the nutrient concentrations were reduced to 0.15mM KNO3 and 0.1mM KH2PO4, respectively. Low temperature treated plants were always supplied with control nutrient solution. Plants from the nitrogen and phosphorus experiment as well as the control temperature plants were exposed to 28Â°C during the day and 20Â°C during the night. Low temperature treatment was limited to the night period and was reduced to 4Â°C for the 10h dark period. Source leaf lamina were harvested at day 20 (low temperature experiment) or day 30 after start of germination (low nitrogen and low phosphorus experiment) for parallel analysis of transcriptome, metabolome and ion profiles. The molecular data is further supplemented by phenotypic characterization of the maize seedlings under investigation.

Dataset Information

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets