Project description:Transcriptional profiling of 4 maize varieties comparing genetic root response under control temperature conditions with genetic root response under low temperature conditions
Project description:Flavonoid biosynthesis in grape berry skin is affected by environmental factors such as light and temperature. However, the components of the light-signaling and low-temperature-induced ABA signaling networks related to flavonoid accumulation in grape berry skin have not been fully elucidated. To clarify details of the possible light- and ABA-related signal transduction networks, we performed comprehensive transcriptome analysis using grape berries cultured under different light and temperature conditions. We identified 40 light-inducible genes, 55 low-temperature-inducible genes, and 34 genes induced by light plus low temperature.
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.
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 28°C during the day and 20°C during the night. Low temperature treatment was limited to the night period and was reduced to 4°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.