RESUMO
We have functionally characterized the high-affinity phosphate transporter (PiPT) from the root endophyte fungus Piriformospora indica. PiPT belongs to the major facilitator superfamily (MFS). PiPT protein was purified by affinity chromatography (Ni-NTA) and Size Exclusion Chromatography (SEC). The functionality of solubilized PiPT was determined in detergent-solubilized state by fluorescence quenching and in proteoliposomes. In the fluorescence quenching assay, PiPT exhibited a saturation concentration of approximately 2 µM, at a pH of 4.5. Proteoliposomes of size 121.6 nm radius, showed transportation of radioactive phosphate. Vmax was measured to be 232.2 ± 11 pmol/min/mg protein. We have found Km to be 45.8 ± 6.2 µM suggesting high affinity towards phosphate.
Assuntos
Basidiomycota , Proteínas de Transporte de Fosfato , Basidiomycota/metabolismo , Basidiomycota/química , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/química , Proteínas Fúngicas/química , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Endófitos/metabolismo , Endófitos/química , Raízes de Plantas/microbiologia , Raízes de Plantas/química , Fosfatos/metabolismo , Fosfatos/químicaRESUMO
Sulfur is one of the essential nutrients that is required for the adequate growth and development of plants. Sulfur is a structural component of protein disulfide bonds, amino acids, vitamins, and cofactors. Most of the sulfur in soil is present in organic matter and hence not accessible to the plants. Anionic form of sulfur (SO42-) is the primary source of sulfur for plants that are generally present in minimal amounts in the soil. It is water-soluble, so readily leaches out of the soil. Sulfur and sulfur-containing compounds act as signaling molecules in stress management as well as normal metabolic processes. They also take part in crosstalk of complex signaling network as a mediator molecule. Plants uptake sulfate directly from the soil by using their dedicated sulfate transporters. In addition, plants also use the sulfur transporter of a symbiotically associated organism like bacteria and fungi to uptake sulfur from the soil especially under sulfur depleted conditions. So, sulfur is a very important component of plant metabolism and its analysis with different dimensions is highly required to improve the overall well-being of plants, and dependent animals as well as human beings. The deficiency of sulfur leads to stunted growth of plants and ultimately loss of yield. In this review, we have focused on sulfur nutrition, uptake, transport, and inter-organismic transfer to host plants. Given the strong potential for agricultural use of sulfur sources and their applications, we cover what is known about sulfur impact on the plant health. We identify opportunities to expand our understanding of how the application of soil microbes like AMF or other root endophytic fungi affects plant sulfur uptake and in turn plant growth and development.
RESUMO
OBJECTIVES: Patients with cirrhosis have a high rate of 30-day hospital readmission that affects their quality of life and contributes to increased healthcare-related costs. The aim of our study was to identify frequency, predictors, and preventable causes of hospital readmissions among patients with decompensated cirrhosis. METHODS: We retrospectively reviewed electronic medical records of all patients with a confirmed diagnosis of decompensated cirrhosis admitted to Dayton VA Medical Center between 2009 and 2013. Demographics, clinical factors, laboratory values, and outcomes were recorded. Univariate analysis was performed using independent samples t tests and Wilcoxon rank sums tests for continuous variables and χ(2) or Fisher exact tests for categorical variables. A multiple logistic regression analysis was performed for variables found to be significant by univariate analysis to predict the risk factors for 30-day readmission. A detailed chart review was conducted for all patients readmitted within 30 days by a single gastroenterologist to identify the reason for readmission and to decide whether any of these readmissions were preventable. RESULTS: The 30-day readmission rate for decompensated cirrhotic patients was 27.03%. The risk factors for 30-day readmission were higher body mass index (BMI), lower body temperature, higher blood urea nitrogen, higher creatinine, more cirrhosis-related complications, and more readmissions per year per univariate analysis. Multivariable analysis revealed only BMI as a significant predictor of 30-day readmission (P = 0.023). A total of 36.7% of 30-day readmissions were possibly preventable. CONCLUSIONS: The independent variable that predicted 30-day readmission in patients with decompensated cirrhosis was higher BMI. Approximately one-third of 30-day readmissions were possibly preventable. These findings support the need to develop specific interventions for disease management to improve patient care and save on extraneous healthcare costs.