Project description:Many trees form ectomycorrhizal symbiosis with fungi. During symbiosis, the tree roots supply sugar to the fungi in exchange for nitrogen, and this process is critical for the nitrogen and carbon cycles in forest ecosystems. However, the extents to which ectomycorrhizal fungi can liberate nitrogen and modify the soil organic matter and the mechanisms by which they do so remain unclear since they have lost many enzymes for litter decomposition that were present in their free-living, saprotrophic ancestors. Using time-series spectroscopy and transcriptomics, we examined the ability of two ectomycorrhizal fungi from two independently evolved ectomycorrhizal lineages to mobilize soil organic nitrogen. Both species oxidized the organic matter and accessed the organic nitrogen. The expression of those events was controlled by the availability of glucose and inorganic nitrogen. Despite those similarities, the decomposition mechanisms, including the type of genes involved as well as the patterns of their expression, differed markedly between the two species. Our results suggest that in agreement with their diverse evolutionary origins, ectomycorrhizal fungi use different decomposition mechanisms to access organic nitrogen entrapped in soil organic matter. The timing and magnitude of the expression of the decomposition activity can be controlled by the below-ground nitrogen quality and the above-ground carbon supply.
Project description:The carbonate leaching of scandium from the landfilled bauxite residue (red mud) of the Bogoslovsky Aluminum Plant (Russia) and samples of red mud (RM) after alkaline pretreatment has been investigated. The results of kinetic studies allowing to compare and evaluate the effectiveness of different conditions and intensification factors in the process of scandium leaching from RM in carbonate/bicarbonate media are presented. It was determined that for 2.0 mol L-1 Na2CO3 leaching solution ultrasonic treatment under gas (CO2) carbonation conditions in the pH range of 9.5-10.0 allows reducing the scandium leaching time by two times and reaching 40-45% scandium extraction. Leaching of RM in carbonate/bicarbonate media is accompanied by secondary processes (adsorption, hydrolysis, and coprecipitation) leading to a decrease in scandium extraction. The obtained results allow improving understanding of scandium chemical behavior in complex aqueous carbonate/bicarbonate systems and can be used for the optimization of the alternative carbonate process for scandium extraction from RM.
Project description:Purpose:The mud crab Scylla paramamosain is an economically important marine crab in China suffering from severe outbreaks of infectious disease caused by marine bacteria such as Vibrio Parahaemolyticus, resulting in great economic losses. However, the mechanisms involved in the immune response of this crab to bacterial infection are not fully understood. To understand the molecular mechanisms underlying the immune response to such pathogenic bacteria, we used high-throughput deep sequencing technology to investigate the transcriptome and comparative expression profiles of the mud crab S.paramamosain infected with V.parahaemolyticus. Methods: The hemocytes sampled at 0-24h after infection with V.parahaemolyticus were used for transcriptome analysis. The hemocytes sampled at 24 h after injections with V.parahaemolyticus and no injected 0h(as control) were used for gene expression profiling analysis. Results: A total of 52,934,042 reads were obtained and assembled into 186,193 contigs in transcriptional responses of the V.parahaemolyticus-infected mud crab. Via annotation to the NCBI database and the Swissprot database, we obtained 48,934 identified unigenes. In total, 10,139(20.7%) unigenes were classified into Gene Ontology, and 25,349 unigenes were found in 20 KEGG categories. These genes included representatives from almost all functional categories. By using Solexa/Illumina's DeepSAGE, 1213 differentially expressed genes (P value < 0.05) were detected in comparative analysis of the expression profiles between V.parahaemolyticus-infected crabs and control crabs, including 538 remarkably upregulated genes and 675 remarkably downregulated genes. Conclusions: Based on our results, we conclude that the inflammatory response may play an important role in the early stages of infection. The signaling cascades such as the chemokine, JAK-STAT, and MAPK pathways are regulated by V.parahaemolyticus infection. These results revealed changes of multiple signaling pathways involved in immunity during V.parahaemolyticus infection, which will facilitate our comprehensive understanding of the mechanisms involved in the immune response to bacterial infection in the mud crab.