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1.
In Vivo Modulation of Arbuscular Mycorrhizal Symbiosis and Soil Quality by Fungal P Solubilizers.
Della Mónica, IF, Godeas, AM, Scervino, JM
Microbial ecology. 2020;(1):21-29
Abstract
Phosphorus (P) is an essential nutrient with low bioavailability in soils for plant growth. The use of P solubilization fungi (PSF) has arisen as an eco-friendly strategy to increase this nutrient's bioavailability. The effect of PSF inoculation and its combination with P-transporting organisms (arbuscular mycorrhizal fungi, AMF) on plant growth has been previously studied. However, these studies did not evaluate the combined effect of PSF and AMF inoculation on plant growth, symbiosis, and soil quality. Therefore, the aim of this study is to assess the impact of PSF on the AMF-wheat symbiosis establishment and efficiency, considering the effect on plant growth and soil quality. We performed a greenhouse experiment with wheat under different treatments (+/-AMF: Rhizophagus irregularis; +/-PSF strains: Talaromyces flavus, T. helicus L7B, T. helicus N24, and T. diversus) and measured plant growth, AMF root colonization, symbiotic efficiency, and soil quality indicators. No interaction between PSF and R. irregularis was found in wheat growth, showcasing that their combination is not better than single inoculation. T. helicus strains did not interfere with the AMF-wheat symbiosis establishment, while T. diversus and T. flavus decreased it. The symbiotic efficiency was increased by T. flavus and T. helicus N24, and unchanged with T. helicus L7B and T. diversus inoculation. The soil quality indicators were higher with microbial co-inoculation, particularly the alkaline phosphatases parameter, showing the beneficial role of fungi in soil. This work highlights the importance of microbial interactions in the rhizosphere for crop sustainability and soil quality improvement, assessing the effects of PSF on AMF-wheat symbiosis.
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2.
Origin of the 31 P MR signal at 5.3 ppm in patients with critical limb ischemia.
Sedivy, P, Dezortova, M, Drobny, M, Dubsky, M, Dusilova, T, Kovar, J, Hajek, M
NMR in biomedicine. 2020;(6):e4295
Abstract
An unknown intense signal (Pun ) with a mean chemical shift of 5.3 ppm was observed in 31 P MR spectra from the calf muscles of patients with the diabetic foot syndrome. The aim of the study was to identify the origin of this signal and its potential as a biomarker of muscle injury. Calf muscles of 68 diabetic patients (66.3 ± 8.6 years; body mass index = 28.2 ± 4.3 kg/m2 ) and 12 age-matched healthy controls were examined by (dynamic) 31 P MRS (3 T system, 31 P/1 H coil). Phantoms (glucose-1-phosphate, Pi and PCr) were measured at pH values of 7.05 and 7.51. At rest, Pun signals with intensities higher than 50% of the Pi intensity were observed in 10 of the 68 examined diabetic subjects. We tested two hypothetical origins of the Pun signal: (1) phosphorus from phosphoesters and (2) phosphorus from extra- and intracellular alkaline phosphate pools. 2,3-diphosphoglycerate and glucose-1-phosphate are the only phosphoesters with signals in the chemical shift region close to 5.3 ppm. Both compounds can be excluded: 2,3-diphosphoglycerate due to the missing second signal component at 6.31 ppm; glucose-1-phosphate because its chemical shifts are about 0.2 ppm downfield from the Pi signal (4.9 ppm). If the Pun signal is from phosphate, it represents a pH value of 7.54 ± 0.05. Therefore, it could correspond to signals of Pi in mitochondria. However, patients with critical limb ischemia have rather few mitochondria and so the Pun signal probably originates from interstitia. Our data suggest that the increased Pun signal observed in patients with the diabetic foot syndrome is a biomarker of severe muscular damage.
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3.
Behavior of Calcium, Phosphorus, and Parathormone Before Transplantation and in Months 1, 3, 6, 9, and 12 After Transplantation.
Pérez, RE, Santiago, JC, López, MC, Rosales Morales, KB, Zavalza Camberos, PA, Olayo, RB, Gómez, RR, Cancino López, JD, Morinelli Astorquizaga, MA, Díaz, ER, et al
Transplantation proceedings. 2020;(4):1152-1156
Abstract
BACKGROUND Bone mineral disease after transplantation persists and is an issue that must be addressed owing to the cardiovascular impact it presents. The objective of this study is to present the behavior of calcium, phosphorus, and parathormone (PTH) before renal transplantation (RT) and throughout the 12 months after transplant surgery. METHODS A longitudinal observational study of RT patients was performed from 2013 to 2017 in 2 renal transplant units in Mexico. In total, 1009 records of patients with RT were analyzed. Calcium, phosphorus, and PTH levels were studied before transplantation and for 12 months after. Central tendency and dispersion were measured, the difference of means was established with chi square or student t tests, and the significant value of P was set at <.05. We also used the SPSS statistical package, version 25. RESULTS Phosphorus had a median pre-RT of 5.73, which decreased to 2.8 in the first month post-transplant and then increased to 3.41 at 12 months post-RT. The median PTH, on the other hand, started at 420.60 and decreased to 67.45. Calcium began at 9.04 and hit a plateau of 9.58 during month 12 after the surgical event. CONCLUSIONS Of the 3 biochemical parameters evaluated, phosphorus was the one that most corrected itself after transplantation. Despite a tendency toward hypophosphatemia in the first month after transplantation, it began to normalize from month 6 on. Meanwhile, calcium was the biochemical value that changed the least after transplantation.
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4.
Binding patterns and dynamics of double-stranded DNA on the phosphorene surface.
Li, B, Xie, X, Duan, G, Chen, SH, Meng, XY, Zhou, R
Nanoscale. 2020;(17):9430-9439
Abstract
Phosphorene, a monolayer of black phosphorus, has emerged as one of the most promising two-dimensional (2D) nanomaterials for various applications in the post-graphene-discovery period due to its highly anisotropic structure and novel properties. In order to apply phosphorene in biomedical fields, it is crucial to understand how it interacts with biomolecules. Herein, we use both molecular dynamics (MD) simulations and experimental techniques to investigate the interactions of phosphorene with a dsDNA segment. Our results reveal that dsDNA can form a stable binding on the phosphorene surface through the terminal base pairs and adopt an upright orientation regardless of its initial configurations. Moreover, the binding strength of dsDNA with phosphorene is found to be mild and does not cause significant distortion in the internal structure of dsDNA. This phenomenon is attributed to the weaker dispersion interaction between dsDNA and phosphorene. Further analysis of the free energy profile calculated by the umbrella sampling technique suggests that the puckered surface morphology significantly reduces the adsorption free energy of DNA bases to phosphorene. Compared to graphene, phosphorene is found to show a milder attraction to DNA, which is confirmed by our electrophoresis experiments. We believe that these findings provide valuable insight into the molecular interactions between phosphorene and dsDNA which may prompt further investigation of phosphorene for future biomedical applications.
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5.
Nitrogen-phosphorus interplay: old story with molecular tale.
Hu, B, Chu, C
The New phytologist. 2020;(4):1455-1460
Abstract
Nitrogen (N) and phosphorus (P) are the two most abundant mineral nutrients used by plants, and are also the mostly widely used fertilizer elements driving crop yield improvement in agricultural production. The coordinated utilization of N and P is essential to maintain optimal plant growth and achieve maximal crop yield. The signaling pathways of N and P are generally studied separately, so our understanding of N-P interactions is very limited. A series of recent studies have revealed the critical components regulating N-P interactions in both Arabidopsis thaliana and rice (Oryza sativa), and have shed light on our in-depth understanding of the network integrating N and P signaling pathways. Here, we summarize recent progress on N-P interaction and propose possible working mechanisms integrating these N-P interactive regulation pathways. We further discuss future work that might reveal the N-P interactive regulation network in plants.
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6.
Dynamics in plant roots and shoots minimize stress, save energy and maintain water and nutrient uptake.
Arsova, B, Foster, KJ, Shelden, MC, Bramley, H, Watt, M
The New phytologist. 2020;(3):1111-1119
Abstract
Plants are inherently dynamic. Dynamics minimize stress while enabling plants to flexibly acquire resources. Three examples are presented for plants tolerating saline soil: transport of sodium chloride (NaCl), water and macronutrients is nonuniform along a branched root; water and NaCl redistribute between shoot and soil at night-time; and ATP for salt exclusion is much lower in thinner branch roots than main roots, quantified using a biophysical model and geometry from anatomy. Noninvasive phenotyping and precision agriculture technologies can be used together to harness plant dynamics, but analytical methods are needed. A plant advancing in time through a soil and atmosphere space is proposed as a framework for dynamic data and their relationship to crop improvement.
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7.
Strength and size of phosphorus-rich patches determine the foraging strategy of Neyraudia reynaudiana.
Cai, L, Wang, Y, Tigabu, M, Hou, X, Wu, P, Zhou, C, Ma, X
BMC plant biology. 2020;(1):545
Abstract
BACKGROUND Under natural conditions, soil nutrients are heterogeneously distributed, and plants have developed adaptation strategies to efficiently forage patchily distributed nutrient. Most previous studies examined either patch strength or patch size separately and focused mainly on root morphological plasticity (increased root proliferation in nutrient-rich patch), thus the effects of both patch strength and size on morphological and physiological plasticity are not well understood. In this study, we examined the foraging strategy of Neyraudia reynaudiana (Kunth) Keng ex Hithc, a pioneer grass colonizing degraded sites, with respect to patch strength and size in heterogeneously distributed phosphorus (P), and how foraging patchily distributed P affects total plant biomass production. Plants were grown in sand-culture pots divided into ½, ¼, 1/6 compartments and full size and supplied with 0 + 0/30, 0 + 7.5/30 and 7.5 + 0/30 mg P/kg dry soil as KH2PO4 or 0 + 15/15, 0 + 18.5/ 18.5, 7.5 + 15/15 mg kg - 1 in the homogenous treatment. The first amount was the P concentration in the central region, and that the second amount was the P concentration in the outer parts of the pot. RESULTS After 3 months of growth under experimental conditions, significantly (p < 0.05) high root elongation, root surface area, root volume and average root diameter was observed in large patches with high patch strength. Roots absorbed significantly more P in P-replete than P-deficient patches. Whole plant biomass production was significantly higher in larger patches with high patch strength than small patches and homogeneous P distribution. CONCLUSION The result demonstrates that root morphological and physiological plasticity are important adaptive strategies for foraging patchily distributed P and the former is largely determined by patch strength and size. The results also establish that foraging patchily distributed P resulted in increased total plant biomass production compared to homogeneous P distribution.
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8.
Norfloxacin-induced effect on enhanced biological phosphorus removal from wastewater after long-term exposure.
Xu, Q, Liu, X, Yang, G, Wang, D, Wu, Y, Li, Y, Huang, X, Fu, Q, Wang, Q, Liu, Y, et al
Journal of hazardous materials. 2020;:122336
Abstract
In this study, long-term experiments were performed under synthetic wastewater conditions to evaluated the potential impacts of norfloxacin (NOR) (10, 100 and 500 μg/L) on enhanced biological phosphorus removal (EBPR). Experimental result showed that long-term exposure to 10 μg/L NOR induced negligible effects on phosphorus removal. The presence of 100 μg/L NOR slightly decreased phosphorus removal efficiency to 94.41 ± 1.59 %. However, when NOR level further increased to 500 μg/L, phosphorus removal efficiency was significantly decreased from 97.96 ± 0.8 5% (control) to 82.33 ± 3.07 %. The mechanism study revealed that the presence of 500 μg/L NOR inhibited anaerobic phosphorus release and acetate uptake as well as aerobic phosphorus uptake during long-term exposure. It was also found that 500 μg/L NOR exposure suppressed the activity of key enzymes related to phosphorus removal but promoted the transformations of intracellular polyhydroxyalkanoate and glycogen. Microbial analysis revealed that that the presence of 500 μg/L NOR reduced the abundances of polyphosphate accumulating organisms but increased glycogen accumulating organisms, as compared the control.
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9.
Comparing levels of vitamin D, calcium and phosphorus in normotensive pregnant women and pregnant women with preeclampsia.
Abbasalizadeh, S, Abam, F, Mirghafourvand, M, Abbasalizadeh, F, Taghavi, S, Hajizadeh, K
Journal of obstetrics and gynaecology : the journal of the Institute of Obstetrics and Gynaecology. 2020;(8):1069-1073
Abstract
Vitamin D and calcium deficiency have been reported as one of the causes of preeclampsia. In this study, levels of vitamin D, calcium and phosphorus were evaluated in 51 normotensive pregnant women and 52 women with preeclampsia at the gestational age between 28 and 36 weeks in Tabriz. Logistic regression and general linear models were used for comparing levels and means of vitamin D, calcium and phosphorus between the two groups adjusting for education and Body Mass Index (BMI). The results showed that mean serum vitamin D (p = .73), calcium (p = .12) and phosphorus (p = .60) levels were not significantly different between the groups after adjusting for education and BMI. Based on this study, no relationship was observed between vitamin D deficiency and preeclampsia; however, it was seen that the hypocalcaemia could increase the risk of preeclampsia up to 8.5 times. Based on our results and the literature, it seems that further studies need to be done to provide more insights into this area.Impact statementWhat is already known on this subject? Preeclampsia is one of the three leading causes of maternal morbidity and mortality worldwide. Despite the importance of preeclampsia, the causes and methods of prevention of this disease are still unknown. Deficiency of vitamin D affects the calcium balance of mothers and fetuses and has also been reported as one of the causes of preeclampsia disease. Reducing serum calcium can lead to increased blood pressure in preeclamptic women. Changes in calcium metabolism during pregnancy could be one of the potential causes of preeclampsia. Although the association of vitamin D, calcium and phosphorus with preeclampsia have been discussed previously, the results are not consistent.What do the results of this study add? The results showed that mean serum vitamin D, calcium and phosphorus levels were not significantly different between the groups.What are the implications of these findings for clinical practice and/or future research? Based on this study, no relationship was observed between vitamin D deficiency and preeclampsia; however, it was seen that the hypocalcaemia could increase the risk of preeclampsia by up to 8.5 times. Based on our results and the literature, it seems that further studies need to be done to provide more insights into this area.
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10.
Characteristics of Patients Who Achieve Serum Phosphorus Control on Sucroferric Oxyhydroxide or Sevelamer Carbonate: A post hoc Analysis of a Phase 3 Study.
Covic, AC, Sprague, SM, Rastogi, A, Ketteler, M, Walpen, S, Perrin, A, Floege, J
Nephron. 2020;(9):428-439
Abstract
INTRODUCTION Control of hyperphosphatemia in patients on dialysis remains a major challenge. OBJECTIVE This study evaluated predictors of serum phosphorus (sP) control among dialysis patients treated with noncalcium, oral phosphate binder therapy in a phase 3 clinical trial. METHODS Post hoc analyses were performed using data for patients with hyperphosphatemia who received 52 weeks of treatment with sucroferric oxyhydroxide (SFOH) or sevelamer carbonate (sevelamer). Patients were categorized into those who achieved sP control (n = 302; defined as sP ≤ 5.5 mg/dL at week 52), and those with uncontrolled sP (n = 195; sP >5.5 mg/dL at week 52). Because SFOH and sevelamer have previously demonstrated similar effects on chronic kidney disease-mineral-bone disorder parameters in this study, the treatment groups were pooled. RESULTS Average age at baseline was higher among sP-controlled versus sP-uncontrolled patients (56.9 vs. 53.4 years; p = 0.005). Baseline sP levels were significantly lower among sP-controlled versus sP-uncontrolled patients (7.30 vs. 7.85 mg/dL; p < 0.001), and sP reductions from baseline were significantly greater in the sP-controlled group (-2.89 vs. -0.99 mg/dL at week 52; p < 0.001). Logistic regression analysis identified higher baseline sP levels (odds ratio [OR] = 0.86, 95% confidence interval [CI]: 0.765-0.960), no concomitant active vitamin D therapy use (OR = 0.51, 95% CI: 0.328-0.804), and higher body mass index at baseline (OR = 0.96, 95% CI: 0.937-0.992) as significant predictors of uncontrolled sP. CONCLUSION This analysis indicates that sP control may be more challenging in younger patients with high sP levels. Closer monitoring and management of serum phosphorus levels may be required in this population.