Project description:To study whether and how soil nitrogen conditions affect the ecological effects of long-term elevated CO2 on microbial community and soil ecoprocess, here we investigated soil microbial community in a grassland ecosystem subjected to ambient CO2 (aCO2, 368 ppm), elevated CO2 (eCO2, 560 ppm), ambient nitrogen deposition (aN) or elevated nitrogen deposition (eN) treatments for a decade. Under the aN condition, a majority of microbial function genes, as measured by GeoChip 4.0, were increased in relative abundance or remained unchanged by eCO2. Under the eN condition, most of functional genes associated with carbon, nitrogen and sulfur cycling, energy processes, organic remediation and stress responses were decreased or remained unchanged by eCO2, while genes associated with antibiotics and metal resistance were increased. The eCO2 effects on fungi and archaea were largely similar under both nitrogen conditions, but differed substantially for bacteria. Coupling of microbial carbon or nitrogen cycling genes, represented by positive percentage and density of gene interaction in association networks, was higher under the aN condition. In accordance, changes of soil CO2 flux, net N mineralization, ammonification and nitrification was higher under the aN condition. Collectively, these results demonstrated that eCO2 effects are contingent on nitrogen conditions, underscoring the difficulty toward predictive modeling of soil ecosystem and ecoprocesses under future climate scenarios and necessitating more detailed studies.
Project description:A3_Microorganisms under Elevated CO2 along with elevated temperature (550 ppm along with 2 degree higher temperature compared to control chamber) Metagenome
Project description:To study long-term elevated CO2 and enriched N deposition interactive effects on microbial community and soil ecoprocess, here we investigated soil microbial community in a grassland ecosystem subjected to ambient CO2 (aCO2, 368 ppm), elevated CO2 (eCO2, 560 ppm), ambient nitrogen deposition (aN) or elevated nitrogen deposition (eN) treatments for a decade. There exist antagonistic CO2×N interactions on microbial functional genes associated with C, N, P S cycling processes. More strong antagonistic CO2×N interactions are observed on C degradation genes than other genes. Remarkably antagonistic CO2×N interactions on soil microbial communities could enhance soil C accumulation.
2018-05-01 | GSE98512 | GEO
Project description:Transcriptome of eggplant under elevated CO2
Project description:In the present study, we sought genes that are involved in the variation of the enhancement of plant growth rate among the Arabidopsis thaliana ecotypes in elevated CO2 condition. We performed a combination analysis of a genome wide association study (GWAS), and a transcriptome study to seek the candidate genes. GWAS was performed using the growth analysis data obtained at Oguchi et al. and the whole genome data from 31 ecotypes. The transcriptome analysis was performed for 6 ecotypes that had contrasting CO2 responses in the growth rate. We analyzed not only annotated coding genes but also small coding genes (30–100 amino acids) identified by Hanada et al., most of which were shown to play roles in cell-to-cell signaling, because it has been shown that a number of small coding genes play significant roles in environmental responses. We also studied the effect of the altered expression of the candidate genes on the plant growth rate in elevated CO2 condition using over-expression (OX) transgenics and RNA interference (RNAi) transgenics. We show that transgenic plants of three genes had significantly higher growth rate under the elevated CO2 condition.
Project description:This work aims to study the effect of the elevated CO2 concentration on the tomato plant response to the toxicity provoked by ammonium nutrition. Tomato plants (Solanum lycopersicum L. cv. Agora Hybrid F1, Vilmorin®) were grown for 4 week with 15 mM of nitrogen, supplied as nitrate or ammonium, at ambient or elevated CO2 conditions (400 ppm or 800 ppm). Transcription profiling by array was carried out in roots for the four growth conditions assayed and gene expression comparisons were done between N sources and CO2 conditions: i) genes differentially expressed in response to the atmospheric CO2 concentration (800 ppm vs 400 ppm CO2) under nitrate or ammonium nutrition; ii) genes differentially expressed in response to the N source (ammonium vs nitrate) under ambient or elevated condition. 3 biological replicates for each growth condition were analysed.CO2).
Project description:Elevated atmospheric CO2 can influence the structure and function of rhizosphere microorganisms by altering root growth and the quality and quantity of compounds released into the rhizosphere via root exudation. In these studies we investigated the transcriptional responses of Bradyrhizobium japonicum cells growing in the rhizosphere of soybean plants exposed to elevated atmospheric CO2. The results of microarray analyses indicated that atmospheric elevated CO2 concentration indirectly influences on expression of large number of Bradyrhizobium genes through soybean roots. In addition, genes involved in C1 metabolism, denitrification and FixK2-associated genes, including those involved in nitrogen fixation, microanaerobic respiration, respiratory nitrite reductase, and heme biosynthesis, were significantly up-regulated under conditions of elevated CO2 in the rhizosphere, relative to plants and bacteria grown under ambient CO2 growth conditions. The expression profile of genes involved in lipochitinoligosaccharide Nod factor biosynthesis and negative transcriptional regulators of nodulation genes, nolA and nodD2, were also influenced by plant growth under conditions of elevated CO2. Taken together, results of these studies indicate that growth of soybeans under conditions of elevated atmospheric CO2 influences gene expressions in B. japonicum in the soybean rhizosphere, resulting in changes to carbon/nitrogen metabolism, respiration, and nodulation efficiency.