Project description:Maize and rice are the two most economically important grass crops and utilize distinct forms of photosynthesis to fix carbon: C4 and C3 respectively. Relative to C3 photosynthesis, C4 photosynthesis reduces photorespiration and affords higher water and nitrogen use efficiencies under hot arid conditions. To define key innovations in C4 photosynthesis, we profiled metabolites and gene expression along a developing leaf gradient. A novel statistical method was implemented to compare transcriptomes from these two species along a unified leaf developmental gradient and define candidate cis-regulatory elements and transcription factors driving photosynthetic gene expression. We also present comparative primary and secondary metabolic profiles along the gradients that provide new insight into nitrogen and carbon metabolism in C3 and C4 grasses. These resources, including community viewers to access and mine these datasets, will enable the elucidation and engineering of C4 photosynthetic networks to improve the photosynthetic capacity of C3 and C4 grasses.
2014-10-12 | GSE54274 | GEO
Project description:Linking bacterial community composition to water salinity along environmental gradients
Project description:the transcriptome changes in long-term different salinity gradients were determined to investigate the related gene responsible for the molecular involvements to M. nipponense after long-term salinity exposure.
Project description:Maize and rice are the two most economically important grass crops and utilize distinct forms of photosynthesis to fix carbon: C4 and C3 respectively. Relative to C3 photosynthesis, C4 photosynthesis reduces photorespiration and affords higher water and nitrogen use efficiencies under hot arid conditions. To define key innovations in C4 photosynthesis, we profiled metabolites and gene expression along a developing leaf gradient. A novel statistical method was implemented to compare transcriptomes from these two species along a unified leaf developmental gradient and define candidate cis-regulatory elements and transcription factors driving photosynthetic gene expression. We also present comparative primary and secondary metabolic profiles along the gradients that provide new insight into nitrogen and carbon metabolism in C3 and C4 grasses. These resources, including community viewers to access and mine these datasets, will enable the elucidation and engineering of C4 photosynthetic networks to improve the photosynthetic capacity of C3 and C4 grasses. [Maize] Nine day old third leaves of maize were cut into fifteen 1 cm segments; samples were pooled from an average of seven plants per biological replicate and six biological replicates in total were collected on different dates. [Rice] 14 day old third leaves of rice were cut into eleven 2 cm segments, samples were pooled from an average of 15 plants per biological replicate and four replicates in total were collected.
Project description:Quantitative RNA sequencing (RNA-seq) and the complementary phenotypic assays were implemented to investigate the transcriptional responses of Chromohalobacter salexigens to osmotic and heat stress. These conditions trigger the synthesis of ectoine and hydroxyectoine, two compatible solutes of biotechnological interest. Our findings revealed that both stresses make a significant impact on C. salexigens global physiology. Apart from compatible solute metabolism, the most relevant adaptation mechanisms were related to “oxidative- and protein-folding- stress responses”, “modulation of respiratory chain and related components”, and “ion homeostasis”. A general salt-dependent induction of genes related to the metabolism of ectoines, as well as repression of ectoine degradation genes by temperature, was observed. Different oxidative stress response mechanisms, secondary or primary, were induced at low and high salinity respectively, and repressed by temperature. A higher sensitivity to H2O2 was observed at high salinity, regardless of temperature. Low salinity induced genes involved in “protein-folding-stress response”, suggesting disturbance of protein homeostasis. Transcriptional shift of genes encoding three types of respiratory NADH dehydrogenases, ATP synthase, quinone pool, Na+/H+ antiporters, and sodium-solute symporters, was observed depending on salinity and temperature, suggesting modulation of the components of the respiratory chain and additional systems involved in the generation of H+ and/or Na+ gradients. Remarkably, the Na+ intracellular content remained constant regardless of salinity and temperature. Disturbance of Na+- and H+-gradients with specific ionophores suggested that both gradients influence ectoine production, but with differences depending on the solute, salinity, and temperature conditions. Flagellum genes were strongly induced by salinity, and further induced by temperature. However, salt-induced cell motility was reduced at high temperature, possibly caused by an alteration of Na+ permeability by temperature, as dependence of motility on Na+-gradient was observed. The transcriptional induction of genes related to the synthesis and transport of siderophores correlated with a higher siderophore production and intracellular iron content only at low salinity. In addition, compared to low salinity external iron increased hydroxyectoine accumulation by 20% at high salinity, but reduced the intracellular content of ectoines by 50% at high salinity plus high temperature. These findings support the relevance of iron homeostasis for osmoadaptation, thermoadaptation and accumulation of ectoines, in C. salexigens
Project description:The Atlantic cod (Gadus morhua L.) is one of the most important species in the Baltic Sea with high ecological and economical value. To explore the differences in adaptation to salinity between Baltic cod from different regions, western (Kiel Bight) and eastern (Gdańsk Bay) samples were analyzed through oligonucleotide microarray.
Project description:The Atlantic cod (Gadus morhua L.) is one of the most important species in the Baltic Sea with high ecological and economical value. To explore the differences in adaptation to salinity between Baltic cod subpopulation: western (Kiel Bight) and eastern (Gdańsk Bay) samples were analyzed through genome-wide oligonucleotide microarray.
Project description:In the present study, we compared transcriptional response to salinity between male and female individuals of Populus yunnanensis. We found that several functional groups of genes involved in important pathways were differentially expressed, including photosynthesis-related genes which were mainly up-regulated in males but down-regulated in females. This gene expression pattern is consistent with physiological observation that salinity inhibited photosynthetic capacity more in females than in males. In conclusion, our study provided molecular evidence of sexual differences in poplar salinity tolerance. Identified sex-related genes in salinity tolerance and their functional groups will enhance our understanding of sexual differences to salinity stress at the transcription level.