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Biological Chemistry Nov 2020Phosphorus (P) is a crucial element and diatoms, unicellular phototrophic organisms, evolved efficient strategies to handle limiting phosphorus concentrations in the... (Review)
Review
Phosphorus (P) is a crucial element and diatoms, unicellular phototrophic organisms, evolved efficient strategies to handle limiting phosphorus concentrations in the oceans. In the last decade, several groups investigated the model diatom Phaeodactylum tricornutum concerning phosphate homeostasis mechanisms. Here, we summarize the actual status of knowledge by linking the available data sets, thereby indicating experimental limits but also future research directions.
Topics: Acclimatization; Diatoms; Models, Biological; Phosphorus; Stress, Physiological
PubMed: 32845857
DOI: 10.1515/hsz-2020-0197 -
Proceedings of the National Academy of... Jun 2019The supply of nutrients is a fundamental regulator of ocean productivity and carbon sequestration. Nutrient sources, sinks, residence times, and elemental ratios vary...
The supply of nutrients is a fundamental regulator of ocean productivity and carbon sequestration. Nutrient sources, sinks, residence times, and elemental ratios vary over broad scales, including those resulting from climate-driven changes in upper water column stratification, advection, and the deposition of atmospheric dust. These changes can alter the proximate elemental control of ecosystem productivity with cascading ecological effects and impacts on carbon sequestration. Here, we report multidecadal observations revealing that the ecosystem in the eastern region of the North Pacific Subtropical Gyre (NPSG) oscillates on subdecadal scales between inorganic phosphorus (P ) sufficiency and limitation, when P concentration in surface waters decreases below 50-60 nmol⋅kg In situ observations and model simulations suggest that sea-level pressure changes over the northwest Pacific may induce basin-scale variations in the atmospheric transport and deposition of Asian dust-associated iron (Fe), causing the eastern portion of the NPSG ecosystem to shift between states of Fe and P limitation. Our results highlight the critical need to include both atmospheric and ocean circulation variability when modeling the response of open ocean pelagic ecosystems under future climate change scenarios.
Topics: Aquatic Organisms; Carbon Cycle; Ecosystem; Iron; Iron Deficiencies; Microbiota; Pacific Ocean; Periodicity; Phosphorus; Tropical Climate
PubMed: 31182581
DOI: 10.1073/pnas.1900789116 -
Journal of the American Society of... Feb 2009Although hyperphosphatemia is a risk factor for mortality, there are limited data on whether therapy with phosphorus binders affects survival. We analyzed a prospective...
Although hyperphosphatemia is a risk factor for mortality, there are limited data on whether therapy with phosphorus binders affects survival. We analyzed a prospective cohort study of 10,044 incident hemodialysis patients using Cox proportional hazards analyses to compare 1-yr all-cause mortality among patients who were or were not treated with phosphorus binders. We performed intention-to-treat analyses to compare patients who began treatment with phosphorus binders during the first 90 d after initiating hemodialysis (n = 3555) with those who remained untreated during that period (n = 5055). We also performed as-treated analyses that modeled phosphorus binder treatment as a time-dependent exposure. We compared survival in a subcohort of treated (n = 3186) and untreated (n = 3186) patients matched by their baseline serum phosphate levels and propensity score of receiving phosphorus binders during the first 90 d. One-year mortality was 191 deaths/1000 patient-years at risk. Treatment with phosphorus binders was independently associated with decreased mortality compared with no treatment in the intention-to-treat, as-treated, and matched analyses. The results were independent of baseline and follow-up serum phosphate levels and persisted in analyses that excluded deaths during the first 90 d of hemodialysis. In summary, treatment with phosphorus binders is independently associated with improved survival among incident hemodialysis patients. Although confirmatory studies are needed in the dialysis setting, future placebo-controlled, randomized trials of phosphorus binders might focus on predialysis patients with chronic kidney disease and normal serum phosphate levels.
Topics: Aged; Cohort Studies; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Phosphorus; Prospective Studies; Renal Dialysis; Research Design; Time Factors; Treatment Outcome
PubMed: 19092121
DOI: 10.1681/ASN.2008060609 -
Revue Scientifique Et Technique... Sep 1991Despite some variability in the data, the author has been able to establish the average characteristics of animal wastes, and to formulate an overall view of nitrogen... (Review)
Review
Despite some variability in the data, the author has been able to establish the average characteristics of animal wastes, and to formulate an overall view of nitrogen and phosphorus wastes originating from livestock, in order to compare them with other wastes. Nitrogen is originally present mainly in the form of dissolved ammonia, whereas phosphorus is present in inorganic particles. Ammonium nitrogen is toxic for the aquatic fauna and, in favourable conditions, can be oxidised into nitrates and nitrites, which are undesirable constituents, capable of affecting the health of consumers. Phosphorus and nitrogen compounds in excess of the requirements for soil fertilisation are responsible, among other things, for degrading the quality of surface water, leading to eutrophication.
Topics: Animals; Animals, Domestic; Feces; Humans; Nitrogen; Phosphorus; Soil Pollutants; Water Pollution
PubMed: 1782421
DOI: No ID Found -
Oecologia Oct 2017Plant growth in northern forest ecosystems is considered to be primarily nitrogen limited. Nitrogen deposition is predicted to change this towards...
Plant growth in northern forest ecosystems is considered to be primarily nitrogen limited. Nitrogen deposition is predicted to change this towards co-limitation/limitation by other nutrients (e.g., phosphorus), although evidence of such stoichiometric effects is scarce. We utilized two forest fertilization experiments in southern Sweden to analyze single and combined effects of nitrogen and phosphorus on the productivity, composition, and diversity of the ground vegetation. Our results indicate that the productivity of forest ground vegetation in southern Sweden is co-limited by nitrogen and phosphorus. Additionally, the combined effect of nitrogen and phosphorus on the productivity was larger than when applied solely. No effects on species richness of any of these two nutrients were observed when applied separately, while applied in combination, they increased species richness and changed species composition, mainly by promoting more mesotrophic species. All these effects, however, occurred only for the vascular plants and not for bryophytes. The tree layer in a forest has a profound impact on the productivity and diversity of the ground vegetation by competing for both light and nutrients. This was confirmed in our study where a combination of nitrogen and high tree basal area reduced cover of the ground vegetation compared to all the other treatments where basal area was lower after stand thinning. During the past decades, nitrogen deposition may have further increased this competition from the trees for phosphorus and gradually reduced ground vegetation diversity. Phosphorus limitation induced by nitrogen deposition may, thus, contribute to ongoing changes in forest ground vegetation.
Topics: Biodiversity; Environmental Pollutants; Forests; Human Activities; Nitrogen; Phosphorus; Sweden; Trees
PubMed: 28884383
DOI: 10.1007/s00442-017-3945-x -
Applied and Environmental Microbiology Aug 2016Phosphorus (P) plays a fundamental role in the physiology and biochemistry of all living things. Recent evidence indicates that organisms in the oceans can break down...
UNLABELLED
Phosphorus (P) plays a fundamental role in the physiology and biochemistry of all living things. Recent evidence indicates that organisms in the oceans can break down and use P forms in different oxidation states (e.g., +5, +3, +1, and -3); however, information is lacking for organisms from soil and sediment. The Cuatro Ciénegas Basin (CCB), Mexico, is an oligotrophic ecosystem with acute P limitation, providing a great opportunity to assess the various strategies that bacteria from soil and sediment use to obtain P. We measured the activities in sediment and soil of different exoenzymes involved in P recycling and evaluated 1,163 bacterial isolates (mainly Bacillus spp.) for their ability to use six different P substrates. DNA turned out to be a preferred substrate, comparable to a more bioavailable P source, potassium phosphate. Phosphodiesterase activity, required for DNA degradation, was observed consistently in the sampled-soil and sediment communities. A capability to use phosphite (PO3 (3-)) and calcium phosphate was observed mainly in sediment isolates. Phosphonates were used at a lower frequency by both soil and sediment isolates, and phosphonatase activity was detected only in soil communities. Our results revealed that soil and sediment bacteria are able to break down and use P forms in different oxidation states and contribute to ecosystem P cycling. Different strategies for P utilization were distributed between and within the different taxonomic lineages analyzed, suggesting a dynamic movement of P utilization traits among bacteria in microbial communities.
IMPORTANCE
Phosphorus (P) is an essential element for life found in molecules, such as DNA, cell walls, and in molecules for energy transfer, such as ATP. The Valley of Cuatro Ciénegas, Coahuila (Mexico), is a unique desert characterized by an extreme limitation of P and a great diversity of microbial life. How do bacteria in this valley manage to obtain P? We measured the availability of P and the enzymatic activity associated with P release in soil and sediment. Our results revealed that soil and sediment bacteria can break down and use P forms in different oxidation states and contribute to ecosystem P cycling. Even genetically related bacterial isolates exhibited different preferences for molecules, such as DNA, calcium phosphate, phosphite, and phosphonates, as substrates to obtain P, evidencing a distribution of roles for P utilization and suggesting a dynamic movement of P utilization traits among bacteria in microbial communities.
Topics: Bacteria; Biodiversity; Ecosystem; Geologic Sediments; Phosphorus; Phylogeny; Soil; Soil Microbiology
PubMed: 27235437
DOI: 10.1128/AEM.00160-16 -
BMC Plant Biology Dec 2013miR399 and miR827 are both involved in conserved phosphorus (P) deficiency signalling pathways. miR399 targets the PHO2 gene encoding E2 enzyme that negatively regulates...
BACKGROUND
miR399 and miR827 are both involved in conserved phosphorus (P) deficiency signalling pathways. miR399 targets the PHO2 gene encoding E2 enzyme that negatively regulates phosphate uptake and root-to-shoot allocation, while miR827 targets SPX-domain-containing genes that negatively regulate other P-responsive genes. However, the response of miR399 and miR827 to P conditions in barley has not been investigated.
RESULTS
In this study, we investigated the expression profiles of miR399 and miR827 in barley (Hordeum vulagre L.) under P-deficient and P-sufficient conditions. We identified 10 members of the miR399 family and one miR827 gene in barley, all of which were significantly up-regulated under deficient P. In addition, we found many isomirs of the miR399 family and miR827, most of which were also significantly up-regulated under deficient P. Several isomirs of miR399 members were found to be able to cleave their predicted targets in vivo. Surprisingly, a few small RNAs (sRNAs) derived from the single-stranded loops of the hairpin structures of MIR399b and MIR399e-1 were also found to be able to cleave their predicted targets in vivo. Many antisense sRNAs of miR399 and a few for miR827 were also detected, but they did not seem to be regulated by P. Intriguingly, the lowest expressed member, hvu-miR399k, had four-fold more antisense sRNAs than sense sRNAs, and furthermore under P sufficiency, the antisense sRNAs are more frequent than the sense sRNAs. We identified a potential regulatory network among miR399, its target HvPHO2 and target mimics HvIPS1 and HvIPS2 in barley under P-deficient and P-sufficient conditions.
CONCLUSIONS
Our data provide an important insight into the mechanistic regulation and function of miR399, miR827 and their isomirs in barley under different P conditions.
Topics: Gene Expression Regulation, Plant; Hordeum; MicroRNAs; Phosphorus; RNA, Plant
PubMed: 24330740
DOI: 10.1186/1471-2229-13-214 -
Journal of Renal Nutrition : the... Sep 2007Phosphorus-containing additives are increasingly being added to food products. We sought to determine the potential impact of these additives. We focused on chicken...
OBJECTIVE
Phosphorus-containing additives are increasingly being added to food products. We sought to determine the potential impact of these additives. We focused on chicken products as an example.
METHODS
We purchased a variety of chicken products, prepared them according to package directions, and performed laboratory analyses to determine their actual phosphorus content. We used ESHA Food Processor SQL Software (version 9.8, ESHA Research, Salem, OR) to determine the expected phosphorus content of each product.
RESULTS
Of 38 chicken products, 35 (92%) had phosphorus-containing additives listed among their ingredients. For every category of chicken products containing additives, the actual phosphorus content was greater than the content expected from nutrient database. For example, actual phosphorus content exceeded expected phosphorus content by an average of 84 mg/100 g for breaded breast strips. There was also a great deal of variation within each category. For example, the difference between actual and expected phosphorus content ranged from 59-165 mg/100 g for breast patties. Two 100-g servings of additive-containing products contained, on average, 440 mg of phosphorus, or about half the total daily recommended intake for dialysis patients.
CONCLUSIONS
Phosphorus-containing additives significantly increase the amount of phosphorus in chicken products. Available nutrient databases do not reflect this higher phosphorus content, and the variation between similar products makes it impossible for patients and dietitians to accurately estimate phosphorus content. We recommend that dialysis patients limit their intake of additive-containing products, and that the phosphorus content of food products be included on nutrition facts labels.
Topics: Animals; Chickens; Databases, Factual; Food Additives; Food Analysis; Humans; Nutritional Physiological Phenomena; Phosphorus; Poultry Products; Renal Dialysis; Renal Insufficiency
PubMed: 17720105
DOI: 10.1053/j.jrn.2007.05.008 -
Giornale Italiano Di Nefrologia :... Feb 2016Phosphorus has been shown to be a predictor of cardiovascular mortality in kidney disease subjects. Phosphorus was discovered in 1669 and was considered a philosophers...
Phosphorus has been shown to be a predictor of cardiovascular mortality in kidney disease subjects. Phosphorus was discovered in 1669 and was considered a philosophers stone, it was used as medicament but there were reported deaths after its use. High serum levels of phosphorus are associated with increased risk for cardiovascular disease in the general population in subjects free from chronic kidney disease. Phosphorus can be defined as a useful and hazardous element for public health.
Topics: History, 15th Century; History, 16th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; History, Ancient; History, Medieval; Phosphorus
PubMed: 26913899
DOI: No ID Found -
PloS One 2015The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P...
The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P fertilization rate. A study of the relationship between the soil Olsen P concentration and the P balance (P input minus P output) and their variations among different fertilization patterns will help to provide useful information for proper management of P fertilization. In this paper, the two investigated long-term experiments were established on black soils in the northeast region of China. Six fertilization treatments were selected: (1) unfertilized (CK); (2) nitrogen only (N); (3) nitrogen and potassium (NK); (4) nitrogen and phosphorus (NP); (5) nitrogen, phosphorus, and potassium (NPK); and (6) nitrogen, phosphorus, potassium and manure (NPKM). The results showed that the average Olsen P concentrations in the black soils at Gongzhuling and Harbin (16- and 31-year study periods, respectively), decreased by 0.49 and 0.56 mg kg-1 a-1, respectively, without P addition and increased by 3.17 and 1.78 mg kg-1 a-1, respectively, with P fertilization. The changes in soil Olsen P concentrations were significantly (P<0.05) correlated with the P balances at both sites except for the NP and NPK treatments at Gongzhuling. Under an average deficit of 100 kg ha-1 P, the soil Olsen P concentration at both sites decreased by 1.36~3.35 mg kg-1 in the treatments without P addition and increased by 4.80~16.04 mg kg-1 in the treatments with 100 kg ha-1 of P accumulation. In addition, the changes in Olsen P concentrations in the soil with 100 kg ha-1of P balance were significantly correlated with the P activation coefficient (PAC, percentage of Olsen P to total P, r=0.99, P<0.01) and soil organic matter content (r=0.91, P<0.01). A low pH was related to large changes of Olsen P by 1 kg ha-1 of P balance. These results indicated that soil organic matter and pH have important effects on the change in soil Olsen P by 1 kg ha-1 of P balance.
Topics: Agriculture; Fertilizers; Hydrogen-Ion Concentration; Manure; Nitrogen; Phosphorus; Plants; Potassium; Soil; Time Factors
PubMed: 26177293
DOI: 10.1371/journal.pone.0131713