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.
Project description:We found that primary root (PR) is more resistant to salt stress compared with crown roots (CR) and seminal roots (SR). To understand better salt stress responses in maize roots, six RNA libraries were generated and sequenced from primary root (PR), primary roots under salt stress (PR-salt) , seminal roots (SR), seminal roots under salt stress (SR-salt), crown roots (CR), and crown roots under salt stress (CR-salt). Through integrative analysis, we identified 444 genes regulated by salt stress in maize roots, and found that the expression patterns of some genes and enzymes involved in important pathway under salt stress, such as reactive oxygen species scavenging, plant hormone signal perception and transduction, and compatible solutes synthesis differed dramatically in different maize roots. 16 of differentially expressed genes were selected for further validation with quantitative real time RT-PCR (qRT-PCR).We demonstrate that the expression patterns of differentially expressed genes are highly diversified in different maize roots. The differentially expressed genes are correlated with the differential growth responses to salt stress in maize roots. Our studies provide deeper insight into the molecular mechanisms about the differential growth responses of different root types in response to environmental stimuli in planta.
Project description:NILs were created for the detailed genetic mapping of a QTL (gFW9.1) in tomato. Residual heterozygocity in recombinant inbred lines from the cross S. lycopersicum var. cerasiforme (parental accession E9) × S. pimpinellifolium line (parental accession L5) was used for the generation of a pair of NILs of which line E9 had DNA from parent E9 on a large section of chromosome 9 (5-56 Mb), whereas line L5 had parent L5 DNA. These two lines were tested as rootstocks grafted to a common scion (cv. Boludo) in multi-stress conditions - low phosphorus and drought stress compared to high phosphorus and well-watered conditions. RNA for transcriptomic analysis was prepared from root tissues. Secondary use of data: In a study aiming to identify genes that respond to multiple abiotic stresses, microarray data obtained from different plant species and under different stresses was analysed. A number of conserved stress-responsive genes were identified whose expression was differentially regulated in tomato roots in response to one or several stresses. 10 of these genes were validated as reliable biomarkers whose expression levels are related to different signalling pathways involved in adaptive stress responses. This dataset comprises part of the full stress dataset and is for plant roots harvested after growth under low phosphorus and drought conditions, compared to plant roots harvested after growth under sufficient phosphorus and well watered conditions.
Project description:Purpose: The goal of this analysis is that to reveal the different expression pattern in chilling-tolerant and chilling susceptible lines under chilling stress.Chilling is a major stress to plants of subtropical and tropical origins including maize. To reveal molecular mechanisms underlying chilling tolerance and chilling survival, we investigated maize transcriptome responses to chilling stress in differentiated leaves and roots as well as in crowns with meristem activity for survival. Chilling stress on maize shoots and roots is found to each contribute to seedling lethality in maize. Comparison of maize lines with different chilling tolerance capacity reveals that chilling survival in maize is highly associated with upregulation in leaves and crowns of abscisic acid response pathway, transcriptional regulators and metal ion transporters as well as downregulation of heat response in crowns. Comparison of chilling treatment on whole and part of the plants reveals that response to distal-chilling is very distinct from, and sometimes opposite to, response to local- or whole-plant chilling in both leaves and roots, suggesting a communication between shoots and roots in environmental perception. In sum, this study details chilling responses in leaves, roots and crowns and reveals potential chilling survival mechanism in maize, which lays ground for further understanding survival and tolerance mechanisms under low but non-freezing temperatures in tropical and subtropical plants.
Project description:We found that primary root (PR) is more resistant to salt stress compared with crown roots (CR) and seminal roots (SR). To understand better salt stress responses in maize roots, six RNA libraries were generated and sequenced from primary root (PR), primary roots under salt stress (PR-salt) , seminal roots (SR), seminal roots under salt stress (SR-salt), crown roots (CR), and crown roots under salt stress (CR-salt). Through integrative analysis, we identified 444 genes regulated by salt stress in maize roots, and found that the expression patterns of some genes and enzymes involved in important pathway under salt stress, such as reactive oxygen species scavenging, plant hormone signal perception and transduction, and compatible solutes synthesis differed dramatically in different maize roots. 16 of differentially expressed genes were selected for further validation with quantitative real time RT-PCR (qRT-PCR).We demonstrate that the expression patterns of differentially expressed genes are highly diversified in different maize roots. The differentially expressed genes are correlated with the differential growth responses to salt stress in maize roots. Our studies provide deeper insight into the molecular mechanisms about the differential growth responses of different root types in response to environmental stimuli in planta. Examination of three root types of maize under salt treatment for understanding the different responding mechenism to salt stress.
Project description:Chilling is a major stress to plants of subtropical and tropical origins including maize. To reveal molecular mechanisms underlying chilling tolerance and chilling survival, we investigated maize transcriptome responses to chilling stress in differentiated leaves and roots as well as in crowns with meristem activity for survival. Chilling stress on maize shoots and roots is found to each contribute to seedling lethality in maize. Comparison of maize lines with different chilling tolerance capacity reveals that chilling survival in maize is highly associated with upregulation in leaves and crowns of abscisic acid response pathway, transcriptional regulators and cold response as well as downregulation of heat response in crowns. Comparison of chilling treatment on whole and part of the plants reveals that response to distal-chilling is very distinct from, and sometimes opposite to, response to local- or whole-plant chilling in both leaves and roots, suggesting a communication between shoots and roots in environmental perception. In sum, this study details chilling responses in leaves, roots and crowns and reveals potential chilling survival mechanism in maize, which lays ground for further understanding survival and tolerance mechanisms under low but non-freezing temperatures in tropical and subtropical plants.
Project description:ngs2021_19_rhizophagus-responses of maize to the arbuscular fungus rhizophagus irregularis mitigate n deficiency stress-What is the impact of Rhizophagus irregularis on maize transcriptome under different N nutrition conditions, what is the impact of N on R. irregularis transcriptome in maize roots.-After 4 days of germination, maize seeds were sown in pots filled with sterile mix 1:1 clay beads:unfertilized peat. Inoculation performed in 3 times with Rhizohphagus irregularis spores purchased at Agronutrition. First inoculation perfomed with 500 spores/plant at sowing. Two other incoulations performed the following week and 2 weeks later with 100 spore per plant each.