scholarly journals Physiological Responses to Fe Deficiency in Split-Root Tomato Plants: Possible Roles of Auxin and Ethylene?

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1000
Author(s):  
Silvia Celletti ◽  
Youry Pii ◽  
Fabio Valentinuzzi ◽  
Raphael Tiziani ◽  
Maria Chiara Fontanella ◽  
...  
Keyword(s):  
Ethylene Biosynthesis ◽  
Physiological Adaptation ◽  
Fe Deficiency ◽  
Homogeneous Distribution ◽  
Ethylene Signaling ◽  
Ferric Reductase ◽  
Heterogeneous Distribution ◽  
Solanum Lycopersicum L ◽  
Systemic Signaling ◽  
Split Root

Iron (Fe) bioavailability in soils is often limited and can be further exacerbated by a non- homogeneous distribution in the soil profile, which has been demonstrated to vary both in space and time. Consequently, plants respond with morphological and physiological modifications at the root level involving a complex local and systemic signaling machinery. The present work unravels the role of two phytohormones (i.e., ethylene and auxin) and their integrated signaling in plant response to Fe deficiency. Inhibitors of auxin polar transport and of ethylene biosynthesis (N-1-naphthylphthalamic acid - NPA and aminoethoxyvinylglycine - AVG, respectively) were applied on tomato (Solanum lycopersicum L.) plants grown by the split-root technique, which allows to simulate condition of Fe heterogeneous distribution. Results showed that plants, exposed to an uneven Fe supply, triggered a complex auxin-ethylene signaling. A systemic action of auxin on FERRIC REDUCTASE OXIDASE 1 (SlFRO1) expression was revealed, while ethylene signaling was effective both locally and systemically. In addition, the investigation of Fe concentration in tissues showed that when leaves overcame Fe deficiency a Fe “steady state” was maintained. Therefore, physiological adaptation to this heterogeneous Fe supply could be mediated by the integration of the complex signaling pathways prompted by both auxin and ethylene activities.

scholarly journals Influence of Ethylene Signaling in the Crosstalk Between Fe, S, and P Deficiency Responses in Arabidopsis thaliana

2021 ◽  
Vol 12 ◽  
Author(s):  
María José García ◽  
Macarena Angulo ◽  
Carlos García ◽  
Carlos Lucena ◽  
Esteban Alcántara ◽  
...  
Keyword(s):  
Plant Hormone ◽  
Reductase Activity ◽  
Nutrient Deficiency ◽  
Fe Deficiency ◽  
Energy Costs ◽  
Ethylene Signaling ◽  
Ferric Reductase ◽  
Wild Type ◽  
P Deficiency ◽  
Specific Manner

To cope with P, S, or Fe deficiency, dicot plants, like Arabidopsis, develop several responses (mainly in their roots) aimed to facilitate the mobilization and uptake of the deficient nutrient. Within these responses are the modification of root morphology, an increased number of transporters, augmented synthesis-release of nutrient solubilizing compounds and the enhancement of some enzymatic activities, like ferric reductase activity (FRA) or phosphatase activity (PA). Once a nutrient has been acquired in enough quantity, these responses should be switched off to minimize energy costs and toxicity. This implies that they are tightly regulated. Although the responses to each deficiency are induced in a rather specific manner, crosstalk between them is frequent and in such a way that P, S, or Fe deficiency can induce responses related to the other two nutrients. The regulation of the responses is not totally known but some hormones and signaling substances have been involved, either as activators [ethylene (ET), auxin, nitric oxide (NO)], or repressors [cytokinins (CKs)]. The plant hormone ET is involved in the regulation of responses to P, S, or Fe deficiency, and this could partly explain the crosstalk between them. In spite of these crosslinks, it can be hypothesized that, to confer the maximum specificity to the responses of each deficiency, ET should act in conjunction with other signals and/or through different transduction pathways. To study this latter possibility, several responses to P, S, or Fe deficiency have been studied in the Arabidopis wild-type cultivar (WT) Columbia and in some of its ethylene signaling mutants (ctr1, ein2-1, ein3eil1) subjected to the three deficiencies. Results show that key elements of the ET transduction pathway, like CTR1, EIN2, and EIN3/EIL1, can play a role in the crosstalk among nutrient deficiency responses.

scholarly journals The effect of sediment thermal conductivity on vertical groundwater flux estimates

2018 ◽  
Author(s):  
Eva Sebok ◽  
Sascha Müller
Keyword(s):  
Thermal Conductivity ◽  
Homogeneous Distribution ◽  
Temperature Profiles ◽  
High Flux ◽  
Water Interface ◽  
Heterogeneous Distribution ◽  
Groundwater Flux ◽  
Sediment Temperature ◽  
Spatially Distributed ◽  
Lagoon Environment

Abstract. Vertical sediment temperature profiles are frequently used to estimate vertical fluid fluxes. In these applications using heat as a tracer of groundwater flow, the thermal conductivity of saturated sediments (ke) is often given as a standard literature value and assumed to have a homogeneous distribution in the vertical space. In this study vertical sediment temperature profiles were collected both in a high-flux stream and a low-flux lagoon environment in a sand-, and peat-covered area. ke was measured at the location of each temperature profile at several depths below the sediment-water interface up to 0.5 m with a measurement spacing of 0.1 m. In general ke values measured in this study ranged between 0.55 and 2.96 W m−1 °C−1 with an increase with depth from the sediment-water interface. The effect of using a vertically homogeneous or heterogeneous distribution of measured ke values on vertical flux estimates was studied with a steady-state HydroGeoSphere model. In the high-flux stream environment estimated fluxes varied between 0.03 and 0.71 m d−1 and in the low-flux lagoon between 0.02 and 0.23 m d−1. It was found, that using a vertically heterogeneous distribution of sediment thermal conductivity did not considerably change the fit between observed and simulated temperature data compared to a homogeneous distribution of ke. However, depending on the choice of sediment thermal conductivities, flux estimates decreased by up to 64 % or increased by up to 75 % compared to using a standard ke sediment thermal conductivity for sand, frequently assumed by previous local studies. Hence, our study emphasizes the importance of using spatially distributed thermal properties in heat flux applications in order to obtain more precise flux estimates.

scholarly journals Distribution of complement receptors on human normal and malignant mononuclear cells

Blood ◽  
1980 ◽  
Vol 56 (5) ◽  
pp. 792-797
Author(s):  
RB Slease ◽  
JE Gadek ◽  
MM Frank ◽  
I Scher
Keyword(s):  
Fluorescence Intensity ◽  
Mononuclear Cells ◽  
Human Subjects ◽  
Normal Subjects ◽  
Cell Types ◽  
Lymphocytic Leukemia ◽  
Homogeneous Distribution ◽  
Cell Leukemia ◽  
Peripheral Blood Mononuclear ◽  
Heterogeneous Distribution

Mononuclear cells from normal human subjects and patients with chronic lymphocytic leukemia (CLL), chronic lymphosarcoma cell leukemia (LCL), and hairy cell leukemia (HCL) were labeled with fluoresceinated, purified human C3b (FI-C3b) and analyzed using the fluorescence- activated cell sorter (FACS). FI-C3b labeled 17.6% +/- 6.0% of peripheral blood mononuclear cells (PBM) from 20 normal subjects, which, when separated by the FACS, consisted of B lymphocytes and approximately 5% monocytes. Analyses in which either monocytes or B lymphcoytes were excluded from consideration demonstrated that both these cell types were labeled by the FI-C3b with a heterogeneous distribution of fluorescence intensity, indicating either heterogeneity of CR density or variable avidity of individual CR for the FI-C3b. FACS profiles of PBM ( < 5% monocytes) from 14 of 15 patients with CLL showed a homogeneous distribution of very low fluorescence intensity, with > 60% of the cells being slightly more fluorescent than unlabeled controls. This low, homogeneous distribution of fluorescence is strikingly similar to profiles of CLL cells labeled with anti-Ig reagents and suggests homogeneity of low CR density and/or avidity. Similarly, CR+ mononuclear cells from five patients with HCL and three patients with LCL displayed more homogeneous FI-C3b labeling than normal CR+ PBM. Homogeneity of FI-C3b binding to CLL, LCL, and HCL cells further supports the concept for a clonal origin for these disorders.

scholarly journals Several Yeast Species Induce Iron Deficiency Responses in Cucumber Plants (Cucumis sativus L.)

2021 ◽  
Vol 9 (12) ◽  
pp. 2603
Author(s):  
Carlos Lucena ◽  
María T. Alcalá-Jiménez ◽  
Francisco J. Romera ◽  
José Ramos
Keyword(s):  
Yeast Species ◽  
Reductase Activity ◽  
Hansenula Polymorpha ◽  
Debaryomyces Hansenii ◽  
Root Hairs ◽  
Fe Deficiency ◽  
Ferric Reductase ◽  
Cucumis Sativus L ◽  
Growth System ◽  
Promising Line

Iron (Fe) deficiency is a first-order agronomic problem that causes a significant decrease in crop yield and quality. Paradoxically, Fe is very abundant in most soils, mainly in its oxidized form, but is poorly soluble and with low availability for plants. In order to alleviate this situation, plants develop different morphological and physiological Fe-deficiency responses, mainly in their roots, to facilitate Fe mobilization and acquisition. Even so, Fe fertilizers, mainly Fe chelates, are widely used in modern agriculture, causing environmental problems and increasing the costs of production, due to the high prices of these products. One of the most sustainable and promising alternatives to the use of agrochemicals is the better management of the rhizosphere and the beneficial microbial communities presented there. The main objective of this research has been to evaluate the ability of several yeast species, such as Debaryomyces hansenii, Saccharomyces cerevisiae and Hansenula polymorpha, to induce Fe-deficiency responses in cucumber plants. To date, there are no studies on the roles played by yeasts on the Fe nutrition of plants. Experiments were carried out with cucumber plants grown in a hydroponic growth system. The effects of the three yeast species on some of the most important Fe-deficiency responses developed by dicot (Strategy I) plants, such as enhanced ferric reductase activity and Fe2+ transport, acidification of the rhizosphere, and proliferation of subapical root hairs, were evaluated. The results obtained show the inductive character of the three yeast species, mainly of Debaryomyces hansenii and Hansenula polymorpha, on the Fe-deficiency responses evaluated in this study. This opens a promising line of study on the use of these microorganisms as Fe biofertilizers in a more sustainable and environmentally friendly agriculture.

scholarly journals Intracellular Hemoglobin S Polymerization and the Clinical Severity of Sickle Cell Anemia

Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1777-1783 ◽  
Author(s):  
William N. Poillon ◽  
Bak C. Kim ◽  
Oswaldo Castro
Keyword(s):  
Hemoglobin Concentration ◽  
Significant Negative Correlation ◽  
Clinical Severity ◽  
Homogeneous Distribution ◽  
Mean Corpuscular Hemoglobin ◽  
Heterogeneous Distribution ◽  
Sickle Erythrocytes ◽  
Hb S ◽  
2,3 Dpg

Abstract Recent work has enabled us to quantitate the four variables (2,3-DPG concentration, pHi, non-S hemoglobin composition, and O2 saturation) that modulate the equilibrium solubility (csat) of Hb S inside sickle erythrocytes (SS RBCs). Using measured values of mean corpuscular hemoglobin concentration (MCHC), 2,3-DPG concentration, and %Hb (F+A2), along with estimates of pHiand the Δcsat due to partial oxygenation of SS RBCs in the microcirculation, we calculated the mean polymer fraction (fp) in erythrocytes from 46 SS homozygotes. Values of fp derived from the conservation of mass equation ranged from 0.30 to 0.59. MCHC and %Hb F were major determinants of the magnitude of fp; 2,3-DPG concentration and pHialso contributed, but to a lesser extent. A clinical severity score (CSS) was assigned to each patient based on mean hospitalization rate. There was a weak, but statistically significant, negative correlation between fp and steady state hematocrit (P = .017), but none between fp and whole blood hemoglobin concentration (P = .218). Although there was no correlation between fp and mean number of hospitalization days per year, patients with the greatest number of admissions and hospitalization days were found only among those who had an fp > 0.45. All five patients who died during the follow-up period (median, 7 years; range, 3 to 10 years) had fp values ≥0.48. However, patients with few admissions, low hospitalization days, and long survivals occurred at all fp levels. These results suggest that the clinical course of homozygous SS disease cannot be predicted by mean fpcalculations, which assume a homogeneous distribution of the five variables that modulate intraerythrocytic polymerization. A heterogeneous distribution is more likely; so the amount of polymerized Hb S could vary considerably among cell populations. Factors such as membrane abnormalities and endothelial cell interactions may also contribute to clinical severity.

scholarly journals Ethylene signaling transcription factor promote grape growth induced by exogenous carbon

2019 ◽  
Author(s):  
Xin Zhao ◽  
Ying Wang ◽  
Wen-Fang Li ◽  
Meng-Fei Li ◽  
Zong-Huan Ma ◽  
...  
Keyword(s):  
Plant Growth ◽  
Signaling Pathway ◽  
Growth And Development ◽  
Acc Oxidase ◽  
Ethylene Biosynthesis ◽  
Differentially Expressed ◽  
Ethylene Signaling ◽  
Plant Growth And Development ◽  
Plant Signal Transduction ◽  
Ethylene Signaling Pathway

Abstract Background The carbon can be converted into sugar which is not only important for plant growth and development, but also for plant signal transduction, especially in plant hormone response. The objective of this work was to build available genomic and proteomic resource to investigate the molecular mechanisms of exogenous carbon regulating plant growth and development. Results Grape (Vitis vinifera L. cv. ‘Pinot Noir’) plantlets cultured with exogenous carbon (2% sucrose, 1000 μmol·mol-1 CO2 and with both 2% sucrose and 1000 μmol·mol-1 CO2 were designated as S1, C0 and Cs, respectively). We used S0 (without sucrose, ambient CO2) as CK to analyze the differential expression genes and proteins induced by exogenous carbon. Through the transcriptomic and proteomic analysis, with pooled data for Cs, C0 and S1 compared with CK, 70 differentially expressed genes (DEGs) and 65 differentially expressed proteins (DEPs) were identified. Based on biological functions and physiological characteristics, we identified 8 DEGs and 2 DEPs related to ethylene signaling process. Amongst the DEGs we focussed on ERF TFs, including ERF5 (LOC100244353, LOC100247763, LOC100254616 and LOC100261260), ERF105 (LOC100249507 and LOC100259725), ERF2 (LOC100254640) and CTr (CTr7). Also, there were 2 DEPs related to ethylene metabolism, such as S-adenosylmethionine synthase 5 (SAM synthase 5; XP_002280106.1) and 1-aminocyclopropane-1-carboxylic acid oxidase 2 (ACC oxidase 2; NP_001267871.1) were also identified. The transcriptome and proteome results suggested that exogenous carbon inhibits ethylene biosynthesis through ACC oxidase 2. Additionally, CTr7 and ERF5, which were up-regulated, are related to the ethylene signaling pathway. We speculate that exogenous carbon regulates plant growth through ethylene signaling pathways, but which inhibit ethylene biosynthesis. Conclusions Exogenous carbon regulates the expression of ethylene biosynthesis and signaling related genes, which may improve plant growth through the ethylene signaling pathway.

scholarly journals Intracellular Hemoglobin S Polymerization and the Clinical Severity of Sickle Cell Anemia

Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1777-1783 ◽  
Author(s):  
William N. Poillon ◽  
Bak C. Kim ◽  
Oswaldo Castro
Keyword(s):  
Hemoglobin Concentration ◽  
Significant Negative Correlation ◽  
Clinical Severity ◽  
Homogeneous Distribution ◽  
Mean Corpuscular Hemoglobin ◽  
Heterogeneous Distribution ◽  
Sickle Erythrocytes ◽  
Hb S ◽  
2,3 Dpg

Recent work has enabled us to quantitate the four variables (2,3-DPG concentration, pHi, non-S hemoglobin composition, and O2 saturation) that modulate the equilibrium solubility (csat) of Hb S inside sickle erythrocytes (SS RBCs). Using measured values of mean corpuscular hemoglobin concentration (MCHC), 2,3-DPG concentration, and %Hb (F+A2), along with estimates of pHiand the Δcsat due to partial oxygenation of SS RBCs in the microcirculation, we calculated the mean polymer fraction (fp) in erythrocytes from 46 SS homozygotes. Values of fp derived from the conservation of mass equation ranged from 0.30 to 0.59. MCHC and %Hb F were major determinants of the magnitude of fp; 2,3-DPG concentration and pHialso contributed, but to a lesser extent. A clinical severity score (CSS) was assigned to each patient based on mean hospitalization rate. There was a weak, but statistically significant, negative correlation between fp and steady state hematocrit (P = .017), but none between fp and whole blood hemoglobin concentration (P = .218). Although there was no correlation between fp and mean number of hospitalization days per year, patients with the greatest number of admissions and hospitalization days were found only among those who had an fp > 0.45. All five patients who died during the follow-up period (median, 7 years; range, 3 to 10 years) had fp values ≥0.48. However, patients with few admissions, low hospitalization days, and long survivals occurred at all fp levels. These results suggest that the clinical course of homozygous SS disease cannot be predicted by mean fpcalculations, which assume a homogeneous distribution of the five variables that modulate intraerythrocytic polymerization. A heterogeneous distribution is more likely; so the amount of polymerized Hb S could vary considerably among cell populations. Factors such as membrane abnormalities and endothelial cell interactions may also contribute to clinical severity.

scholarly journals Frequency scaling of seismic attenuation in rocks saturated with two fluid phases

2016 ◽  
Vol 208 (1) ◽  
pp. 221-225 ◽  
Author(s):  
Samuel Chapman ◽  
Beatriz Quintal ◽  
Nicola Tisato ◽  
Klaus Holliger
Keyword(s):  
High Frequency ◽  
Seismic Attenuation ◽  
Fluid Distribution ◽  
Homogeneous Distribution ◽  
Pore Scale ◽  
Frequency Scaling ◽  
Heterogeneous Distribution ◽  
Wave Induced ◽  
Two Fluid ◽  
Fluid Phases

Seismic wave attenuation is frequency dependent in rocks saturated by two fluid phases and the corresponding scaling behaviour is controlled primarily by the spatial fluid distribution. We experimentally investigate the frequency scaling of seismic attenuation in Berea sandstone saturated with two fluid phases: a liquid phase, water, and a gas phase, air, carbon dioxide or nitrogen. By changing from a heterogeneous distribution of mesoscopic gas patches to a homogeneous distribution of pore scale gas bubbles, we observe a significant steepening of the high-frequency asymptote of the attenuation. A transition from one dominant attenuation mechanism to another, from mesoscopic wave-induced fluid flow to wave-induced gas exsolution dissolution (WIGED), may explain this change in scaling. We observe that the high-frequency asymptote, for a homogenous pore scale gas bubble distribution, scales in accord with WIGED.

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