Project description:Nitrogen (N) and phosphorus (P) are pivotal element for proper plant growth and development. We performed microarray analysis of rice shoot and root after nitrogen deficiency (-N) treatment under phosphorus deficiency (-P) condition to obtain a global view of gene regulations associated with plant response to -N under -P condition.
2019-10-06 | GSE73775 | GEO
Project description:Eastern Tropical South Pacific Oxygen Deficient Zone metagenomes
Project description:In agroecosystems, a plant-usable form of nitrogen is mainly generated by legume-based biological nitrogen fixation, a process that requires phosphorus (P) as an essential nutrient. To investigate the physiological mechanism whereby phosphorus influences soybean nodule nitrogen fixation, soybean root nodules were exposed to four phosphate levels: 1 mg/L (P stress), 11 mg/L (P stress), 31 mg/L (Normal P), 61 mg/L (High P) then proteome analysis of nodules was conducted to identify phosphorus-associated proteome changes. We found that phosphorus stress-induced ribosomal protein structural changes were associated with altered key root nodule protein synthesis profiles. Importantly, up-regulated expression of peroxidase was observed as an important phosphorus stress-induced nitrogen fixation-associated adaptation that supported two nodule-associated activities: scavenging of reactive oxygen species (ROS) and cell wall growth. In addition, phosphorus transporter (PT) and purple acid phosphatase (PAPs) were up-regulated that regulated phosphorus transport and utilisation to maintain phosphorus balance and nitrogen fixation function in phosphorus-stressed root nodules.
Project description:Cells arrest growth and enter a quiescent state upon nutrient deprivation. However, the molecular processes by which cells respond to different starvation signals to regulate exit from the cell division cycle and initiation of quiescence remains poorly understood. To study the role of protein expression and signaling in quiescence we combined temporal profiling of the proteome and phosphoproteome using stable isotope labeling with amino acids in cell culture (SILAC) in Saccharomyces cerevisiae (budding yeast). We find that carbon and phosphorus starvation signals activate quiescence through largely distinct proteome and phosphoproteome remodeling. However, increased expression of mitochondrial proteins is essential for quiescence establishment in response to both starvation signals. Whereas the quiescent proteome is established within 6 hours of starvation the quiescent phosphoproteome undergoes continuous changes for at least 30 hours following initial starvation. Deletion of the putative quiescence regulator RIM15, which encodes a serine-threonine kinase, results in reduced survival of cells starved for phosphorus and nitrogen, but not carbon. However, we identified common protein phosphorylation roles for RIM15 in quiescence that are enriched for RNA metabolism and translation. We also find evidence for RIM15-mediated phosphorylation of some targets, including IGO1, prior to starvation consistent with a functional role for RIM15 beyond quiescence regulation. Finally, we find evidence for widespread catabolism of amino acids in response to nitrogen starvation, indicating widespread amino acid recycling via salvage pathways in conditions lacking environmental nitrogen. Our study defines an expanded quiescent proteome and phosphoproteome in yeast, and highlights the multiple coordinated molecular processes at the level of protein expression that are required for quiescence.
Project description:Untargeted proteomics from a 5,000 km+ transect across the central Pacific Ocean from Hawaii to Tahiti. The expedition crossed multiple biogeochemical provinces, inlcuding the oligotrophic North Pacific Subtropical Gyre, the extremety of the Eastern Tropical North Pacific Oxygen Deficient Zone, and the relatively productive equatorial region associated with upwelling. This dataset focuses on the microbial fraction (0.2-3.0 micrometer filter size) and the microbial community dynamics across these biogeochemical provinces, from the surface oceance to the mesopelagic (1,250 m depth maximum).
Project description:Particulate Organic Matter from filter samples (0.2um Supor, 3um Supor, 52 Nitex) in the oxygen deficient zone of the Eastern tropical Northern Pacific.
Project description:<p>Four species of phytoplankton representing important bloom-forming species from three globally important phyla (Bacillariophyta, Haptophyta, and Ochrophyte) were cultured in this study. These species include the cosmopolitan diatom <em>Chaetoceros affinis</em> CCMP159 (isolated from Great South Bay, NY, USA, 1958), the haptophytes<em> Chrysochromulina polylepis </em>CCMP1757 (isolated from the North Sea 1988) and <em>Gephyrocapsa oceanica</em> RCC1303 (isolated from Arachon Bay, France, Jan 1999), and the raphidophyte <em>Heterosigma akashiwo </em>strain CCMP 2393 (isolated from Rehoboth Bay, Delaware, USA). Cultures were grown under three conditions: nitrogen-stress, phosphorus-stress, and replete conditions. Intracellular metabolites were extracted from cultures and analyzed with targeted and untargeted mass spectrometry-based metabolomics methods.</p>