Gene Expression Patterns in Potato Roots Associated with Greater Plant Growth at Low Phosphate Concentrations in the Rhizosphere
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ABSTRACT: There are both financial and environmental reasons for optimising the use of phosphorus (P) fertilisers in potato production. One strategy to effect this is to develop genotypes with greater P use efficiency (PUE), which is generally defined as yield divided by the P available to the crop. In this article we report that potato (Solanum tuberosum L.) genotypes differ in their PUE, expressed both as yield in the field and as shoot biomass when grown hydroponically. When grown hydroponically, PUE was strongly correlated with P uptake efficiency (PUpE, defined as shoot P content), but not with physiological P utilisation efficiency (PUtE, defined as shoot biomass divided by shoot P content). Gene expression in roots differed between potato genotypes, and changed with P supply. A common transcriptional response to reduced P supply was determined in roots of four potato genotypes. This response comprised genes encoding enzymes involved in increasing rhizosphere P availability, phosphate transport, P-sparing metabolism, replacement of phospholipids in cell membranes, and various transcription factors. A specific transcriptional response associated only with roots of genotypes with high yields in the absence of P-fertiliser application in the field (Maris Piper and Stirling) was also identified. Genes involved in this response encoded various transcription factors, proteins facilitating water, solute and auxin transport, and enzymes involved in polyamine metabolism and the biosynthesis of tropane alkaloids.
Project description:Martian regolith (unconsolidated surface material) is a potential medium for plant growth in bioregenerative life support systems during manned missions on Mars. However, hydrated magnesium sulfate mineral levels in the regolith of Mars can reach as high as 10 wt%, and would be expected to be highly inhibitory to plant growth. A global approach was used to identify novel genes with potential to enhance tolerance to high MgSO4 stress. The early Arabidopsis root transcriptome response to elevated concentrations of magnesium sulfate was characterized in col-0, and also between col-0 and the mutant line cax1-1 – a mutant relatively tolerant of high levels of MgSO4•7H2O in soil solution. After 3 weeks of growth under hydroponic conditions, Arabidopsis thaliana col-0 roots were exposed to a basic nutrient solution (0.25 g/L MES, 1/16x MS, pH 5.7) with an additional 2.08 mM magnesium sulfate (total Ca:Mg ratio = 1:15) for 45 min., 90 min., or 180 min., while a col-0 control set was exposed to the basic nutrient solution without additional magnesium sulfate for 45 minutes. Arabidopsis thaliana cax1-1 roots were exposed to the basic nutrient solution with additional magnesium sulfate for 180 min. only. Four replicate containers were harvested for the control and each of the treatment sets, resulting in a total of 20 samples. Gene expression of the col-0 sets exposed to magnesium sulfate treatment for 45 min., 90 min., or 180 min. was compared to gene expression of the col-0 control set. Gene expression of the cax1-1 set exposed to magnesium sulfate treatment for 180 min. was compared to gene expression of the col-0 set exposed to magnesium sulfate treatment for 180 minutes.
Project description:Hydrogen cyanide (HCN) is coproduced with ethylene in plant cells and primarily enzymatically detoxified by the mitochondrial ß-cyanoalanine synthase (CAS-C1). Permanent or transient depletion of CAS-C1 activity in Arabidopsis results in physiological alterations in the plant that suggest that the function of HCN is a gasotransmitter molecule. Label-free quantitative proteomic analysis of enriched mitochondrial samples isolated from the wild type and cas-c1 mutant revealed significant changes in protein content, identifying 451 proteins that are absent or less abundant in cas-c1 and 353 proteins that are only present or more abundant in the mutant background. Gene ontology classification of these proteins highlights proteomic changes that explains the root hairless phenotype and the altered immune response observed in the cas-c1 mutant. The mechanism of action of cyanide as a signaling molecule has been addressed using two proteomic approaches focused on identifying the S-cyanylation of cysteine as a posttranslational modification of proteins. Both the 2-imino-thiazolidine chemical method and the direct untargeted analysis of proteins using LC-MS/MS identified a set of 163 proteins susceptible to S-cyanylation that included sedoheptulose 1, 7-bisphosphatase (SBPase), the peptidyl-prolyl cis-trans isomerase (CYP20-3) and enolase 2 (ENO2). In vitro analysis of these proteins identified that this modification in the SBPase Cys74, CYP20-3 Cys259 and ENO2 Cys346 residues affected the enzymatic activity of the enzymes. GO classification and protein-protein interaction cluster analysis revealed the function of S-cyanylation in the regulation of primary metabolic pathways, such as glycolysis, and the Calvin and S-adenosylmethionine cycles.
Project description:affy_agro-bi_medicago - Identification of genes from the model legume Medicago truncatula whose expression is affected by the plant nitrogen status, with or without inoculation with the symbiotic bacteria Sinorhizobium meliloti. - Comparison of the supernodulant, nitrogen-insensitive, sunn-2 mutant with the A17 wild type genotype.-The plant root systems of plants were split into two parts, each one being installed in a separate compartment. For the â??Sâ?? treatment, one part was supplied with 10 mM NH4NO3 while the other part was supplied with a nitrogen-free nutrient solution. For the â??Lâ?? treatment, one part was supplied 0.5mM NO3- and the other part was supplied with the nitrogen free solution. Eight biological materials (designated AL, AS, SL, SS, IL, IS, NIL, NIS), with three biological repeats for each, were collected and analyzed. The effects of the S and L conditions were investigated on wild-type A17 (AL vs. AS) and sunn-2 mutant plants (SL vs. SS); one set of A17 plants was inoculated with Sinorhizobium meliloti (IL vs. IS), harvested at four days post inoculation and compared to non-inoculated plants (NIL vs. NIS). Keywords: growth in nitrogen-sufficient (s) vs. nitrogen-limited (l) conditions 18 arrays - Medicago
Project description:21 days old (after germination) vegetative wild emmer wheat plants with different drought stress response were grown in hydroponics and shock-drought stressed for 4 and 8 hours. Affymetrix GeneChip Wheat Genome Array was used for transcription profiling.
Project description:Low phosphate concentrations are frequently a constraint for maize growth and development, and therefore, enormous quantities of phosphate fertilizer are expended in maize cultivation, which increases the cost of planting. Low phosphate stress not only increases root biomass but can also cause significant changes in root morphology. Low phosphate availability has been found to favor lateral root growth over primary root growth by dramatically reducing primary root length and increasing lateral root elongation and lateral root density in Arabdopsis. While in our assay when inbred line Q319 subjected to phosphate starvation, The numbers of lateral roots and lateral root primordia were decreased after 6 days of culture in a low phosphate solution (LP) compared to plants grown under normal conditions (sufficient phosphate, SP), and these differences were increased associated with the stress caused by phosphate starvation. However, the growth of primary roots appeared not to be sensitive to low phosphate levels. This is very different to Arabidopsis. To elucidate how low phosphate levels regulate root modifications, especially lateral root development, a transcriptomic analysis of the 1.0-1.5 cm lateral root primordium zone (LRZ) of maize Q319 treated after 2 and 8 days by low phosphate was completed respectively. The present work utilized an Arizona Maize Oligonucleotide array 46K version slides, which contained 46,000 maize 70-mer oligonucleotides designated by TIGR ID, and the sequence information is available at the website of the Maize Oligonucleotide Array Project as the search item representing the >30,000 identifiable unique maize genes (details at http://www.maizearray.org). Keywords: low phosphate, Lateral Root Primordium Zone, maize Two-condition experiment, low phosphate treated lateral root primordium zone of maize root vs. normal cultrued lateral root primordium zone. Biological replicates: 9 control, 9 treated, independently grown and harvested. One replicate per array.
Project description:Alpha-synuclein (aSyn) is a central player in the pathogenesis of synucleinopathies due to its accumulation in typical protein aggregates in the brain. However, it is still unclear how it contributes to neurodegeneration. Type-2 diabetes mellitus is a risk factor for Parkinson’s disease (PD) and, interestingly, a common molecular alteration among these disorders is the age-associated increase in protein glycation. We hypothesized that glycation-induced neuronal dysfunction might be a contributing factor in synucleinopathies. Here, we dissected the specific impact of methylglyoxal (MGO, a glycating agent) in mice overexpressing aSyn in the brain. We found that MGO-glycation potentiates motor, cognitive, olfactory, and colonic dysfunction in aSyn transgenic (Thy1-aSyn) mice that received a single dose of MGO via intracerebroventricular (ICV) injection. aSyn accumulates in the midbrain, striatum, and prefrontal cortex, and protein glycation is increased in the cerebellum and midbrain. SWATH mass spectrometry analysis, used to quantify changes in the brain proteome, revealed that MGO mainly increase glutamatergic-associated proteins in the midbrain (NMDA, AMPA, glutaminase, VGLUT and EAAT1), but not in the prefrontal cortex, where it mainly affects the electron transport chain. Notably, the glycated proteins in the midbrain of Thy1-aSyn mice that received MGO strongly correlate with PD and dopaminergic pathways. Overall, we demonstrated that MGO-induced glycation accelerates PD-like sensorimotor and cognitive alterations and suggest that the increase of glutamatergic signaling may underly these events. Our study sheds new light into the enhanced vulnerability of the midbrain in PD-related synaptic dysfunction and suggests that glycation suppressors and anti-glutamatergic drugs may hold promise as disease-modifying therapies for synucleinopathies.
Project description:Cattle primary cultured hepatocytes (CHs) have been used as a useful in vitro model for drug metabolism studies. However, they suffer some limitations, when compared with the ex vivo liver tissue, such as difficult adhesion to the substrate following isolation, a limited viability and a rapid loss of differentiated characteristics. Therefore, a reliable hepatic in vitro model is actually needed for cattle. As established bovine hepatic cell lines are not available, we characterized the cattle primary CHs' transcriptome by using a cDNA microarray approach and compared it with ex vivo cattle liver tissue as well as with the Madin-Darby Bovine Kidney (MDBK) cells (as an established cell line for transfection purposes).<br>This part of the study compares the primary CHs vs. liver tissue. The comparison of MDBK cells vs. the primary CHs is found under E-MTAB-4430.
Project description:Patient-derived bone tumor (osteosarcoma and giant cell tumor of bone) cells, and the normal mesenchymal stem cells and osteoblasts were cultured and subjected to UV crosslinking (UV) at 254 nm or without crosslinking (noUV) as negative controls. Subsequently, RNA-binding proteins (RBPs) were identified by eRIC.