Phosphate Uptake by Spirodela and Lemna during Early Phosphorus Deficiency

1987 ◽  
Vol 14 (5) ◽  
pp. 561
Author(s):  
I.R McPharlin ◽  
R.L Bieleski
Keyword(s):  
Phosphorus Deficiency ◽  
Fold Increase ◽  
P Fractions ◽  
P Deficiency ◽  
First Order ◽  
Phosphate Ion ◽  
P Concentration ◽  
Uptake Rates ◽  
Spirodela Oligorrhiza

Growth, internal P concentration and Pi uptake was investigated in sterile cultures of Spirodela oligorrhiza (Kurz) Hegelm. and Lemna major L. plants during early P-deficiency. Within 12 h of transfer to a P-deficient medium, Pi uptake rates by P-deficient (- P) plants were enhanced 30-120% compared with P adequate (+ P) controls at 1-1000 �M external [Pi]. The enhancement in Pi uptake rates with P-deficiency normally preceded, and was more pronounced than, other effects of P-deficiency such as reduced growth, reduced internal [P] and appearance of visual symptoms. Enhanced Pi uptake rates in - P compared with +P plants resupplied with Pi was more closely correlated with a fall in the internal [Pi] (r = -0.93 to -0.98) than with a fall in the concentration of three other P fractions (i.e. ester P, lipid P, and residual P). The role of tissue [Pi] in Spirodela and Lemna plants as a possible determinant of Pi uptake rates is discussed. Kinetic analysis showed that enhanced Pi uptake in -P compared with + P plants resupplied with Pi was the result of a 2-4-fold increase in V*max of two first- order systems and not by an increased affinity (i.e. reduced K*m) of the carrier for the phosphate ion.

scholarly journals The External Location of Phosphatase Activity in Phosphorus-Deficient Spirodela Oligorrhiza

1972 ◽  
Vol 25 (4) ◽  
pp. 707 ◽  
Author(s):  
RL Bieleski ◽  
PN Johnson
Keyword(s):  
Phosphatase Activity ◽  
External Medium ◽  
Phosphorus Deficiency ◽  
Fold Increase ◽  
Particle Fraction ◽  
Specific Staining ◽  
P Deficiency ◽  
Intact Plants ◽  
Spirodela Oligorrhiza

Phosphorus deficiency (P deficiency) caused a 10-20�fold increase in phos-phatase activity of S. oligorrhiza homogenates. Specific staining showed that phosphatase in control plants was located primarily in and around the vascular strands, and in P�deficient plants it was located in the epidermis of the root and undersurface of the frond. Dissection experiments showed that roots of P�deficient plants contained a disproportionately high phosphatase activity. When plant and root homogenates were fractionated, phosphatase activity was recovered in the supernatant rather than in any cell particle fraction. However, intact plants released very little phosphatase to the external medium.

scholarly journals An R2R3-type myeloblastosis transcription factor MYB103 is involved in phosphorus remobilization

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Fangwei Yu ◽  
Shenyun Wang ◽  
Wei Zhang ◽  
Hong Wang ◽  
Li Yu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Abiotic Stresses ◽  
Myb Transcription Factor ◽  
Ethylene Signaling ◽  
Biotic And Abiotic Stresses ◽  
P Deficiency ◽  
P Concentration ◽  
Increased Sensitivity

Abstract The members of myeloblastosis transcription factor (MYB TF) family are involved in the regulation of biotic and abiotic stresses in plants. However, the role of MYB TF in phosphorus remobilization remains largely unexplored. In the present study, we show that an R2R3 type MYB transcription factor, MYB103, is involved in phosphorus (P) remobilization. MYB103 was remarkably induced by P deficiency in cabbage (Brassica oleracea var. capitata L.). As cabbage lacks the proper mutant for elucidating the mechanism of MYB103 in P deficiency, another member of the crucifer family, Arabidopsis thaliana was chosen for further study. The transcript of its homologue AtMYB103 was also elevated in response to P deficiency in A. thaliana, while disruption of AtMYB103 (myb103) exhibited increased sensitivity to P deficiency, accompanied with decreased tissue biomass and soluble P concentration. Furthermore, AtMYB103 was involved in the P reutilization from cell wall, as less P was released from the cell wall in myb103 than in wildtype, coinciding with the reduction of ethylene production. Taken together, our results uncover an important role of MYB103 in the P remobilization, presumably through ethylene signaling.

scholarly journals Monopotassium phosphate (KH2PO4) and salicylic acid (SA) as seed priming in Vicia faba L. and Vicia sativa L.

2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Wissal M'Sehli ◽  
Nadia Kallala ◽  
Karima Jaleli ◽  
Amal Bouallegue ◽  
Haythem Mhadhbi
Keyword(s):  
Vicia Faba ◽  
Seedling Establishment ◽  
Plant Biomass ◽  
Phosphorus Deficiency ◽  
Seed Priming ◽  
Vicia Sativa ◽  
P Deficiency ◽  
Exogenous Application ◽  
P Concentration ◽  
The Impact

The first experiment was conducted to evaluate the impact of seed priming on germination behavior and seedling establishment in Vicia faba and Vicia sativa, for that, seeds priming was done using SA (100 µM) and KH2PO4. In order to determine the optimal concentration of KH2PO4 for improving germination, different concentrations were used: 25 µM, 50 µM, and 100 µM. The best germination behavior and seedling establishment were obtained with 25 and 50 µM KH2PO4, respectively for Vicia faba and Vicia sativa. Moreover, data showed that 100 µM of SA improved seed germination as well as the seedling establishment for both species. The second experiment was carried out to investigate the influence of seed priming for improving phosphorous (P) deficiency tolerance. To do, seedling obtained from primed and nonprimed seeds were grown in a hydroponic culture system with three different treatments: control (C, medium containing sufficient P concentration: 360 µM KH2PO4), direct phosphorus-deficient (DD, medium containing only 10 µM KH2PO4), and induced P deficiency by bicarbonate (ID, medium containing sufficient P concentration: 360 µM KH2PO4 + 0.5 g L-1 CaCO3 + 10 mM NaHCO3). Furthermore, the role of exogenous SA applied to P deficiency tolerance enhancement was explored. Seed priming or the exogenous application of SA significantly reduced the severity effect of P deficiency. In fact, the pretreated plants were observed more tolerant to P deficiency as reflected from the significant increase in plant biomass, P uptake, and an efficient antioxidant system. Overall, this paper highlights the beneficial effect of seeds priming or the exogenous application of SA in the improvement of plant tolerance to phosphorus deficiency.

scholarly journals Blood Phosphorus Concentration as an Indicator of Phosphorus Deficiency in Growing Cattle

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 136
Author(s):  
Rob Dixon ◽  
Stephen Anderson ◽  
Lisa Kidd ◽  
Mary Fletcher
Keyword(s):  
Diet Quality ◽  
Rainy Season ◽  
Phosphorus Deficiency ◽  
Cattle Grazing ◽  
Phosphorus Concentration ◽  
Threshold Values ◽  
P Deficiency ◽  
Inorganic P ◽  
P Concentration ◽  
Young Cattle

Inadequate intakes of phosphorus (P) by cattle can cause P deficiency and severely reduce productivity. Blood inorganic P concentration (Pi) is often used as an indicator of P deficiency. Results from two experiments (E1 and E2) with young cattle grazing tropical P-deficient rainy season pastures without or with additional P, or fed in pens on higher energy pelleted diets ranging in P concentration (E3), were used to examine the relationships between Pi and liveweight (LW) gain. When Pi was >2.0 mmol/L average LW gains were 0.71, 0.85 and 1.04 kg/day in E1, E2 and E3, respectively. These differences between experiments were most likely associated with diet limitations other than P. LW gain was related curvilinearly in E1 and E2, and linearly in E3, with Pi. The Pi ranged from ca. 1.0 mmol/L through to 2.5–3.0 mmol/L in each experiment. The reductions in LW gains from the maximum at Pi > 2.0 mmol/L for several lower Pi concentrations were calculated from these relationships. At Pi = 1.0 mmol/L the LW gains were 36–60% of the maximum, at Pi = 1.5 mmol/L LW gains were 59–84% of the maximum, and at Pi = 2.0 mmol/L the LW gains were 82–98% of the maximum. The reductions in LW gain at each Pi were substantially greater for E3 than for E1 and E2. It is concluded that the Pi threshold indicative of P deficiency varies with the diet quality and that the threshold values are substantially higher with higher diet quality.

scholarly journals Response of Soybean Root to Phosphorus Deficiency under Sucrose Feeding: Insight from Morphological and Metabolome Characterizations

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ahui Yang ◽  
Lingjian Kong ◽  
Hui Wang ◽  
Xingdong Yao ◽  
Futi Xie ◽  
...  
Keyword(s):  
Phosphorus Deficiency ◽  
Lateral Roots ◽  
Root Surface ◽  
Root Surface Area ◽  
P Availability ◽  
P Efficiency ◽  
Morphological Response ◽  
P Deficiency ◽  
Soybean Genotypes

Phosphorus (P) is one the least available essential plant macronutrients in soils that is a major constraint on plant growth. Soybean (Glycine max L.) production is often limited due to low P availability. The better management of P deficiency requires improvement of soybean’s P use efficiency. Sugars are implicated in P starvation responses, and a complete understanding of the role of sucrose together with P in coordinating P starvation responses is missing in soybean. This study explored global metabolomic changes in previously screened low-P-tolerant (Liaodou, L13) and low-P-sensitive (Tiefeng 3, T3) soybean genotypes by liquid chromatography coupled mass spectrometry. We also studied the root morphological response to sucrose application (1%) in P-starved soybean genotypes against normal P supply. Root morphology in L13 genotype has significantly improved P starvation responses as compared to the T3 genotype. Exogenous sucrose application greatly affected root length, root volume, and root surface area in L13 genotype while low-P-sensitive genotype, i.e., T3, only responded by increasing number of lateral roots. Root : shoot ratio increased after sucrose treatment regardless of P conditions, in both genotypes. T3 showed a relatively higher number of differentially accumulated metabolites between P-starved and normal P conditions as compared to L13 genotype. Common metabolites accumulated under the influence of sucrose were 5-O-methylembelin, D-glucuronic acid, and N-acetyl-L-phenylalanine. We have discussed the possible roles of the pathways associated with these metabolites. The differentially accumulated metabolites between both genotypes under the influence of sucrose are also discussed. These results are important to further explore the role of sucrose in the observed pathways. Especially, our results are relevant to formulate strategies for improving P efficiency of soybean genotypes with different P efficiencies.

Origin of the phosphorus deficiency observed in declining sugar maple stands in the Quebec Appalachians

1989 ◽  
Vol 19 (1) ◽  
pp. 24-34 ◽  
Author(s):  
D. Paré ◽  
B. Bernier
Keyword(s):  
Sugar Maple ◽  
Phosphorus Deficiency ◽  
Available P ◽  
Major Influence ◽  
P Fractions ◽  
Root Tips ◽  
P Nutrition ◽  
P Deficiency ◽  
Inorganic P ◽  
P Pools

To investigate the origin of the phosphorus (P) deficiency previously observed in declining sugar maple (Acersaccharum Marsh.) in several sites of the Quebec Appalachians, soils originating from 10 maple stands with foliar P concentrations ranging from 0.85 to 2.36 mg • g−1 were subjected to the following analyses: the chemical composition and P pools of L and F horizons, as well as pH, total nitrogen (N), exchangeable cations, total organic and inorganic P, P reserves fractionated according to their availability, and extractable iron (Fe) and aluminum (Al) of Ah (or H) and B horizons. The number of root tips per unit volume of soil was measured at 0–15 cm depth. Foliar P concentrations were positively correlated with P concentrations and P pools of L and F horizons, with the contents of readily available P fractions of the Ah or H horizon, and with the number of root tips to 15 cm depth. In contrast, foliar P concentrations and the available P fractions of the Ah or H horizon were negatively correlated with pH, with total P reserves, and with the concentrations of extractable Fe and Al and amorphous inorganic Fe of this horizon. The characteristics of the B horizon had little effect on P nutrition. It is concluded that under the conditions now prevailing in the Quebec Appalachians, the nature of the humus form may have a major influence on P nutrition of trees. Stands growing on soils with a moderately acid Ah horizon (mull) exhibited low foliar P concentrations, while those growing on soils associated with a mor humus had adequate P nutrition. A hypothesis is presented that may explain these unusual observations.

Phosphorus Deficiency and its Variation among Lakes

1990 ◽  
Vol 47 (6) ◽  
pp. 1077-1084 ◽  
Author(s):  
David J. Currie
Keyword(s):  
United States ◽  
Seasonal Variation ◽  
Water Chemistry ◽  
Rate Constant ◽  
Seasonal Variability ◽  
Bacterial Abundance ◽  
Phosphorus Deficiency ◽  
Northeastern United States ◽  
P Deficiency ◽  
P Concentration

The severity of phosphorus deficiency varies greatly among lakes. Is this variation related to particular morphological, chemical, or biological characteristics of lakes? These questions were addressed by sampling 49 lakes in Quebec, Ontario, and the northeastern United States. The rate constant of orthophosphate uptake (k1), a measure of orthophosphate demand:supply, proved to be only weakly related to watershed area and to the total phosphorus (P) concentration of the water (R2 = 0.210). Abundance of the biota and other aspects of water chemistry were all unrelated to the intensity of P-deficiency as it varies among lakes. In contrast, within-lake seasonal variability of the rate constant of orthophosphate turnover (kt, which is approximately equal to k1) is strongly related to temperature and bacterial abundance (R2 = 0.575 to 0.828). The results indicate that the seasonal variation in phosphorus deficiency depends strongly on bacterioplankton activity, whereas inter-lake variability in phosphorus deficiency is determined mainly by factors other than morphometry, plankton abundance, or trophic richness.

Plasminogen Activation In Vivo upon Intravenous Infusion of DDAVP

1992 ◽  
Vol 67 (01) ◽  
pp. 111-116 ◽  
Author(s):  
Marcel Levi ◽  
Jan Paul de Boer ◽  
Dorina Roem ◽  
Jan Wouter ten Cate ◽  
C Erik Hack
Keyword(s):  
Monoclonal Antibodies ◽  
Plasminogen Activator ◽  
Plasma Levels ◽  
Fold Increase ◽  
Fibrinolytic System ◽  
Plasminogen Activation ◽  
Plasminogen Activator Activity ◽  
Insight Into

SummaryInfusion of desamino-d-arginine vasopressin (DDAVP) results in an increase in plasma plasminogen activator activity. Whether this increase results in the generation of plasmin in vivo has never been established.A novel sensitive radioimmunoassay (RIA) for the measurement of the complex between plasmin and its main inhibitor α2 antiplasmin (PAP complex) was developed using monoclonal antibodies preferentially reacting with complexed and inactivated α2-antiplasmin and monoclonal antibodies against plasmin. The assay was validated in healthy volunteers and in patients with an activated fibrinolytic system.Infusion of DDAVP in a randomized placebo controlled crossover study resulted in all volunteers in a 6.6-fold increase in PAP complex, which was maximal between 15 and 30 min after the start of the infusion. Hereafter, plasma levels of PAP complex decreased with an apparent half-life of disappearance of about 120 min. Infusion of DDAVP did not induce generation of thrombin, as measured by plasma levels of prothrombin fragment F1+2 and thrombin-antithrombin III (TAT) complex.We conclude that the increase in plasminogen activator activity upon the infusion of DDAVP results in the in vivo generation of plasmin, in the absence of coagulation activation. Studying the DDAVP induced increase in PAP complex of patients with thromboembolic disease and a defective plasminogen activator response upon DDAVP may provide more insight into the role of the fibrinolytic system in the pathogenesis of thrombosis.

Exploring Baryon Rich Matter with Heavy-Ion Collisions

2019 ◽  
Vol 64 (7) ◽  
pp. 583 ◽  
Author(s):  
S. Harabasz
Keyword(s):  
Center Of Mass ◽  
Heavy Ion ◽  
State Density ◽  
Heavy Nuclei ◽  
First Order ◽  
Center Of Mass Energy ◽  
Ion Collisions ◽  
Deconfinement Phase Transition ◽  
Ground State Density

Collisions of heavy nuclei at (ultra-)relativistic energies provide a fascinating opportunity to re-create various forms of matter in the laboratory. For a short extent of time (10-22 s), matter under extreme conditions of temperature and density can exist. In dedicated experiments, one explores the microscopic structure of strongly interacting matter and its phase diagram. In heavy-ion reactions at SIS18 collision energies, matter is substantially compressed (2–3 times ground-state density), while moderate temperatures are reached (T < 70 MeV). The conditions closely resemble those that prevail, e.g., in neutron star mergers. Matter under such conditions is currently being studied at the High Acceptance DiElecton Spectrometer (HADES). Important topics of the research program are the mechanisms of strangeness production, the emissivity of matter, and the role of baryonic resonances herein. In this contribution, we will focus on the important experimental results obtained by HADES in Au+Au collisions at 2.4 GeV center-of-mass energy. We will also present perspectives for future experiments with HADES and CBM at SIS100, where higher beam energies and intensities will allow for the studies of the first-order deconfinement phase transition and its critical endpoint.

scholarly journals The SOS Error-Prone DNA Polymerase V Mutasome and β-Sliding Clamp Acting in Concert on Undamaged DNA and during Translesion Synthesis

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1083
Author(s):  
Adhirath Sikand ◽  
Malgorzata Jaszczur ◽  
Linda B. Bloom ◽  
Roger Woodgate ◽  
Michael M. Cox ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Pathogenic Bacteria ◽  
Fold Increase ◽  
Translesion Dna Synthesis ◽  
Sliding Clamp ◽  
Pol V ◽  
Dna Polymerase V ◽  
Acting In Concert

In the mid 1970s, Miroslav Radman and Evelyn Witkin proposed that Escherichia coli must encode a specialized error-prone DNA polymerase (pol) to account for the 100-fold increase in mutations accompanying induction of the SOS regulon. By the late 1980s, genetic studies showed that SOS mutagenesis required the presence of two “UV mutagenesis” genes, umuC and umuD, along with recA. Guided by the genetics, decades of biochemical studies have defined the predicted error-prone DNA polymerase as an activated complex of these three gene products, assembled as a mutasome, pol V Mut = UmuD’2C-RecA-ATP. Here, we explore the role of the β-sliding processivity clamp on the efficiency of pol V Mut-catalyzed DNA synthesis on undamaged DNA and during translesion DNA synthesis (TLS). Primer elongation efficiencies and TLS were strongly enhanced in the presence of β. The results suggest that β may have two stabilizing roles: its canonical role in tethering the pol at a primer-3’-terminus, and a possible second role in inhibiting pol V Mut’s ATPase to reduce the rate of mutasome-DNA dissociation. The identification of umuC, umuD, and recA homologs in numerous strains of pathogenic bacteria and plasmids will ensure the long and productive continuation of the genetic and biochemical journey initiated by Radman and Witkin.

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