Comparison of the transport properties of three plant sucrose carriers expressed in Xenopus oocytes

2000 ◽  
Vol 27 (9) ◽  
pp. 725 ◽  
Author(s):  
Jing-Jiang Zhou ◽  
Anthony J. Miller
Keyword(s):  
Xenopus Oocytes ◽  
Sugar Transport ◽  
Chloride Ions ◽  
Assimilate Transport ◽  
In Planta ◽  
Ph Values ◽  
Sucrose Transporters ◽  
Inward Currents ◽  
High Concentrations ◽  
External Ph

This paper originates from a presentation at the International Conference on Assimilate Transport and Partitioning, Newcastle, NSW, August 1999 Previous work has shown different patterns of expression for the three plant sucrose transporters PmSUC1, PmSUC2 and AtSUC1. Each carrier may therefore have different properties appropriate for the transport function at each location in the plant. To test this hypothesis, a detailed characterisation of each carrier was performed by expressing the protein in Xenopus oocytes. All three carriers were functionally active in oocytes and transported both sucrose and maltose with the sugars eliciting inward currents, which increased at more negative membrane voltages. This effect was greater for AtSUC1 and PmSUC1 than for PmSUC2. The affinities of the carriers for each sugar were different, with PmSUC2 having a 10-fold higher Km for sucrose compared to AtSUC1 and PmSUC1. However, these values for all three carriers were dependent on the external pH and membrane voltage. For both PmSUC1 and PmSUC2 the maximal sugar transport was achieved at external pH values of 6.5–7.5, values which do not appear to be consistent with a proton-coupled mechanism of transport. However, the normal saline used for oocyte experiments contains relatively high concentrations of NaCl that could interfere with the function of the carrier protein. To test this idea the sucrose-elicited currents were measured in saline containing lower concentrations of these ions. Sodium, but not chloride, ions modified the sugar transport activities of the carriers and these effects were different for each carrier, inhibiting AtSUC1 and PmSUC1, but stimulating PmSUC2. The properties of each carrier are discussed in relation to their expression in oocytes and what is known about their pattern of expression in planta.

scholarly journals Proteomic Analysis Reveals the Participation of Energy- and Stress-Related Proteins in the Response of Pseudomonas putida DOT-T1E to Toluene

2005 ◽  
Vol 187 (17) ◽  
pp. 5937-5945 ◽  
Author(s):  
Ana Segura ◽  
Patricia Godoy ◽  
Pieter van Dillewijn ◽  
Ana Hurtado ◽  
Nuria Arroyo ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Energy Demand ◽  
Cell Metabolism ◽  
Sugar Transport ◽  
Krebs Cycle ◽  
High Energy ◽  
Solvent Tolerance ◽  
Flight Mass Spectrometry ◽  
High Concentrations ◽  
Related Proteins

ABSTRACT Pseudomonas putida DOT-T1E is tolerant to toluene and other toxic hydrocarbons through extrusion of the toxic compounds from the cell by means of three efflux pumps, TtgABC, TtgDEF, and TtgGHI. To identify other cellular factors that allow the growth of P. putida DOT-T1E in the presence of high concentrations of toluene, we performed two-dimensional gel analyses of proteins extracted from cultures grown on glucose in the presence and in the absence of the organic solvent. From a total of 531 spots, 134 proteins were observed to be toluene specific. In the absence of toluene, 525 spots were clearly separated and 117 proteins were only present in this condition. Moreover, 35 proteins were induced by at least twofold in the presence of toluene whereas 26 were repressed by at least twofold under these conditions. We reasoned that proteins that were highly induced could play a role in toluene tolerance. These proteins, identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry, were classified into four categories: 1, proteins involved in the catabolism of toluene; 2, proteins involved in the channeling of metabolic intermediates to the Krebs cycle and activation of purine biosynthesis; 3, proteins involved in sugar transport; 4, stress-related proteins. The set of proteins in groups 2 and 3 suggests that the high energy demand required for solvent tolerance is achieved via activation of cell metabolism. The role of chaperones that facilitate the proper folding of newly synthesized proteins under toluene stress conditions was analyzed in further detail. Knockout mutants revealed that CspA, XenA, and Tuf-1 play a role in solvent tolerance in Pseudomonas, although this role is probably not specific to toluene, as indicated by the fact that all mutants grew more slowly than the wild type without toluene.

scholarly journals CHEMICAL AND BIOLOGICAL INDICATORS FOR EVALUATION OF ARCTIC SOIL DEGRADATION AND ITS POTENTIAL TO REMEDIATION

2021 ◽  
Vol 29 (1) ◽  
pp. 33-39
Author(s):  
Tatiana S. Smirnova ◽  
Elena A. Mazlova ◽  
Olga A. Kulikova ◽  
Ilya M. Ostrovkin ◽  
Adam M. Gonopolsky ◽  
...  
Keyword(s):  
Biological Indicators ◽  
Climatic Conditions ◽  
Chloride Ions ◽  
The Arctic ◽  
Environmental Damage ◽  
Arctic Zone ◽  
Arctic Soils ◽  
Arctic Soil ◽  
Restoration Ability ◽  
High Concentrations

In recent years, significant efforts have been made to accelerate the economic development of the Arctic zone, leading to intense environmental pollution of this region, accompanied by the significant impact of accumulated environmental damage in the region. The solution to these problems is difficult due to the remoteness of these areas and severe climatic conditions. Therefore, it is important to evaluate the potential for restoration of arctic soils. For this purpose, various indicators are used, including biological ones. In the analyzed arctic soil samples, high concentrations of petroleum hydrocarbons (up to 47,000 mg/kg) and chloride-ions (0.10–0.14 wt %) were established. Microbioassay demonstrated a presence of hydrocarbon-oxidizing microorganisms: Penicillium, Azotobacter chroococcum, Bacillus subtilis, Pseudomonas oleovorans. A low enzymatic activity and specific Arctic climate point out a low self-restoration ability of the soil, demonstrated the need for its remediation. The microbioassay with microbial strains identification and soil remediation methods suitable for the Arctic zone were recommended.

scholarly journals Role of the SUT1 and SUT2 sugar transporters during stolbur phytoplasma infection in tomato

2020 ◽  
Author(s):  
Federica De Marco ◽  
Brigitte Batailler ◽  
Michael R. Thorpe ◽  
Frédérique Razan ◽  
Rozenn Le Hir ◽  
...  
Keyword(s):  
Redox Homeostasis ◽  
Sugar Transport ◽  
Transcriptional Analysis ◽  
Starch Accumulation ◽  
Metabolic Switch ◽  
Sieve Elements ◽  
Sugar Transporters ◽  
Abnormal Growth ◽  
Sucrose Transporters ◽  
Phytoplasma Infection

SummaryPhytoplasmas inhabit phloem sieve elements and cause abnormal growth and altered sugar partitioning. But how they interact with phloem functions is not clearly known. The phloem responses were investigated in tomato infected by ‘Candidatus Phytoplasma solani’, at the beginning of the symptomatic stage of infection, both in symptomatic and asymptomatic leaves, the first symptoms appearing in the sink top leaf at the stem apex. Antisense lines impaired in the phloem sucrose transporters SUT1 and SUT2 were included. The infection in source leaves was not associated with symptoms. In the symptomatic, sink leaf, yellowing and leaf curling was associated with higher starch accumulation and expression of defense genes. The transcriptional analysis of symptomatic leaf midribs indicated that transcript levels for genes acting in the glycolysis and peroxisome metabolism in infected plants differed from these in non-infected plants. Phytoplasma multiplied actively in at least three additional lower leaves although they were symptomless, with no sign of activation of defense markers, although the rate of exudation of sucrose from these symptomless, source leaves was lower for infected plants. A few metabolites in phloem-enriched exudate were affected by the infection, such as glycolate and aspartate, and some of them were also affected in the control SUT1- and SUT2- antisense lines, in which sucrose retrieval or release in the sieve elements are impaired. A metabolic switch could explain the delivery of more glycolate into the sieve elements of infected plants. The findings suggest a link between sugar transport and redox homeostasis.One sentence summaryAn impairment of sucrose retrieval and release in the sieve elements occurs during phytoplasma infection, associated with changes in sugar and peroxisome metabolism

A Micropuncture Study of Kidney Function in the River Lamprey Lampetra Fluviatilis Adapted to Sea Water

1980 ◽  
Vol 88 (1) ◽  
pp. 239-248
Author(s):  
A. G. LOGAN ◽  
R. MORRIS ◽  
J. C. RANKIN
Keyword(s):  
Fresh Water ◽  
Kidney Function ◽  
Sea Water ◽  
Chloride Ions ◽  
Water Reabsorption ◽  
Plasma Electrolyte ◽  
River Lamprey ◽  
Micropuncture Study ◽  
Urine Composition ◽  
High Concentrations

Micropuncture techniques have been used to investigate kidney function in lampreys adapted to hyperosmotic media. Plasma electrolyte concentrations were maintained well below corresponding concentrations in the external environment. Urine composition was variable, but generally showed high concentrations of magnesium, sulphate and chloride ions. Lampreys in 50% sea water produced urine which was hypo or iso-osmotic to plasma, whereas those in 100% sea water produced hyperosmotic urine. Urine flow rate in 50% sea water was one tenth of that in fresh water, due to a reduction in filtration rate and an increase in water reabsorption by the kidney. As in fresh water, little if any filtered water was reabsorbed by the proximal segment. Almost 90% of filtered water was reabsorbed by the kidney of 100% sea water lampreys and most of this must have occurred in the distal and collecting segments.

Specific Action of Chloride Ions at High Concentrations on Thermoluminescence of Chloroplasts

1998 ◽  
pp. 1223-1225
Author(s):  
M. K. Solntsev ◽  
V. Tashish ◽  
V. A. Karavaev ◽  
A. M. Kuznetsov
Keyword(s):  
Chloride Ions ◽  
High Concentrations

The chemical stability of mendipite, diaboleïte, chloroxiphite, and cumengéite, and their relationships to other secondary lead(II) minerals

1980 ◽  
Vol 43 (331) ◽  
pp. 901-904 ◽  
Author(s):  
D. Alun Humphreys ◽  
John H. Thomas ◽  
Peter A. Williams ◽  
Robert F. Symes
Keyword(s):  
Chloride Ion ◽  
Stability Diagram ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Stability Field ◽  
Cupric Ion ◽  
Free Energy Of Formation ◽  
High Concentrations ◽  
The Stability ◽  
Ph Range

SummaryThe chemical stabilities of mendipite, Pb3O2Cl2, diaboleïte, Pb2CuCl2(OH)4, chloroxiphite, Pb3CuCl2O2(OH)2, and cumengéite, Pb19Cu24Cl42 (OH)44, have been determined in aqueous solution at 298.2 K. Values of standard Gibbs free energy of formation, ΔGf°, for the four minerals are −740, −1160, −1129, and −15163±20 kJ mol−1 respectively. These values have been used to construct the stability diagram shown in fig. I which illustrates their relationships to each other and to the minerals cotunnite, PbCl2, paralaurionite, PbOHCl, and litharge, PbO. This diagram shows that mendipite occupies a large stability field and should readily form from cold, aqueous, mineralizing solutions containing variable amounts of lead and chloride ions, and over a broad pH range. The formation of paralaurionite and of cotunnite requires a considerable increase in chloride ion concentration, although paralaurionite can crystallize under much less extreme conditions than cotunnite. The encroachment of the copper minerals on to the stability fields of those mineral phases containing lead(II) only is significant even at very low relative activities of cupric ion. Chloroxiphite has a large stability field, and at given concentrations of cupric ion, diaboleïte is stable at relatively high aCl−. Cumengéite will only form at high concentrations of chloride ion.

scholarly journals Tropane Alkaloids: Chemistry, Pharmacology, Biosynthesis and Production

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 796 ◽  
Author(s):  
Kathrin Kohnen-Johannsen ◽  
Oliver Kayser
Keyword(s):  
Tropane Alkaloids ◽  
Structural Diversity ◽  
Basic Structure ◽  
In Planta ◽  
Plant Metabolites ◽  
Comprehensive Overview ◽  
Secondary Plant Metabolites ◽  
Pharmaceutical Therapy ◽  
High Concentrations ◽  
Microbial Biosynthesis

Tropane alkaloids (TA) are valuable secondary plant metabolites which are mostly found in high concentrations in the Solanaceae and Erythroxylaceae families. The TAs, which are characterized by their unique bicyclic tropane ring system, can be divided into three major groups: hyoscyamine and scopolamine, cocaine and calystegines. Although all TAs have the same basic structure, they differ immensely in their biological, chemical and pharmacological properties. Scopolamine, also known as hyoscine, has the largest legitimate market as a pharmacological agent due to its treatment of nausea, vomiting, motion sickness, as well as smooth muscle spasms while cocaine is the 2nd most frequently consumed illicit drug globally. This review provides a comprehensive overview of TAs, highlighting their structural diversity, use in pharmaceutical therapy from both historical and modern perspectives, natural biosynthesis in planta and emerging production possibilities using tissue culture and microbial biosynthesis of these compounds.

Preliminary Study on the Removal of Hexavalent Chromium in Wastewater with Reduction of Sulfur Dioxide

2013 ◽  
Vol 864-867 ◽  
pp. 1699-1703
Author(s):  
Ji Ming Wu ◽  
Sheng Gao Cheng
Keyword(s):  
Reaction Time ◽  
Sulfur Dioxide ◽  
Hexavalent Chromium ◽  
Reduction Reaction ◽  
High Concentration ◽  
Reaction Conditions ◽  
Ph Values ◽  
Different Temperatures ◽  
Preliminary Study ◽  
High Concentrations

The paper focused on a self-developed methodology through using sulfur dioxide to deal with high concentration of chromium-containing wastewater. It studied the effects of different pH values, different reaction time, different temperatures and different amounts of sulfur with sulfur dioxide reduction reaction on the chromium-containing wastewater. The results showed that: when the reaction conditions were controlled as follows: the pH values ranged from 2 to 4, the reaction temperature was controlled 40~60°C, the amount of sulfur in theoretical was 1.2 times and the reaction time was 40 min, the hexavalent chromium in the high concentrations of chromium-containing wastewater could be effectively removed.

scholarly journals Antifungal Activity of Silver Ions and Nanoparticles on Phytopathogenic Fungi

Plant Disease ◽  
2009 ◽  
Vol 93 (10) ◽  
pp. 1037-1043 ◽  
Author(s):  
Young-Ki Jo ◽  
Byung H. Kim ◽  
Geunhwa Jung
Keyword(s):  
Antifungal Activity ◽  
Colony Formation ◽  
Magnaporthe Grisea ◽  
Silver Ions ◽  
Pathogenic Fungi ◽  
Chloride Ions ◽  
Plant Diseases ◽  
Plant Pathogenic Fungi ◽  
In Planta

Silver in ionic or nanoparticle forms has a high antimicrobial activity and is therefore widely used for various sterilization purposes including materials of medical devices and water sanitization. There have been relatively few studies on the applicability of silver to control plant diseases. Various forms of silver ions and nanoparticles were tested in the current study to examine the antifungal activity on two plant-pathogenic fungi, Bipolaris sorokiniana and Magnaporthe grisea. In vitro petri dish assays indicated that silver ions and nanoparticles had a significant effect on the colony formation of these two pathogens. Effective concentrations of the silver compounds inhibiting colony formation by 50% (EC50) were higher for B. sorokiniana than for M. grisea. The inhibitory effect on colony formation significantly diminished after silver cations were neutralized with chloride ions. Growth chamber inoculation assays further confirmed that both ionic and nanoparticle silver significantly reduced these two fungal diseases on perennial ryegrass (Lolium perenne). Particularly, silver ions and nanoparticles effectively reduced disease severity with an application at 3 h before spore inoculation, but their efficacy significantly diminished when applied at 24 h after inoculation. The in vitro and in planta evaluations of silver indicated that both silver ions and nanoparticles influence colony formation of spores and disease progress of plant-pathogenic fungi. In planta efficacy of silver ions and nanoparticles is much greater with preventative application, which may promote the direct contact of silver with spores and germ tubes, and inhibit their viability.

scholarly journals Copper Supplementation in Watering Solution Reaches the Xylem But Does Not Protect Tobacco Plants Against Xylella fastidiosa Infection

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 724-730 ◽  
Author(s):  
Qing Ge ◽  
Paul A. Cobine ◽  
Leonardo De La Fuente
Keyword(s):  
Biofilm Formation ◽  
Inductively Coupled Plasma ◽  
Tap Water ◽  
Xylella Fastidiosa ◽  
In Vitro Study ◽  
Optical Emission ◽  
In Planta ◽  
Inductively Coupled ◽  
High Concentrations

Xylella fastidiosa is a xylem-limited plant pathogenic bacterium that causes disease in many crops worldwide. Copper (Cu) is an antimicrobial agent widely used on X. fastidiosa hosts to control other diseases. Although the effects of Cu for control of foliar pathogens are well known, it is less studied on xylem-colonizing pathogens. Previous results from our group showed that low concentrations of CuSO4 increased biofilm formation, whereas high concentrations inhibited biofilm formation and growth in vitro. In this study, we conducted in planta experiments to determine the influence of Cu in X. fastidiosa infection using tobacco as a model. X. fastidiosa-infected and noninfected plants were watered with tap water or with water supplemented with 4 mM or 8 mM of CuSO4. Symptom progression was assessed, and sap and leaf ionome analysis was performed by inductively coupled plasma with optical emission spectroscopy. Cu uptake was confirmed by increased concentrations of Cu in the sap of plants treated with CuSO4-amended water. Leaf scorch symptoms in Cu-supplemented plants showed a trend toward more severe at later time points. Quantification of total and viable X. fastidiosa in planta indicated that CuSO4-amended treatments did not inhibit but slightly increased the growth of X. fastidiosa. Cu in sap was in the range of concentrations that promote X. fastidiosa biofilm formation according to our previous in vitro study. Based on these results, we proposed that the plant Cu homeostasis machinery controls the level of Cu in the xylem, preventing it from becoming elevated to a level that would lead to bacterial inhibition.

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