scholarly journals Rootstock influence on iron uptake responses inCitrusleaves and their regulation under the Fe paradox effect

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3553 ◽  
Author(s):  
Mary-Rus Martinez-Cuenca ◽  
Amparo Primo-Capella ◽  
Ana Quiñones ◽  
Almudena Bermejo ◽  
Maria Angeles Forner-Giner
Keyword(s):  
Stress Responses ◽  
Iron Uptake ◽  
Dry Weight ◽  
Poncirus Trifoliata ◽  
Activity Impairment ◽  
Area Basis ◽  
Increased Sensitivity ◽  
Citrus Leaves ◽  
Total Tissue ◽  
Fe Chlorosis

Background and aimsThis work evaluates the regulation of iron uptake responses in Citrus leaves and their involvement in the Fe paradox effect.MethodsExperiments were performed in field-grown ‘Navelina’ trees grafted onto two Cleopatra mandarin ×Poncirus trifoliata(L.) Raf. hybrids with different Fe-chlorosis symptoms: 030146 (non-chlorotic) and 030122 (chlorotic).ResultsChlorotic leaves were smaller than non-chlorotic ones for both dry weight (DW) and area basis, and exhibited marked photosynthetic state affection, but reduced catalase and peroxidase enzymatic activities. Although both samples had a similar total Fe concentration on DW, it was lower in chlorotic leaves when expressed on an area basis. A similar pattern was observed for the total Fe concentration in the apoplast and cell sap and in active Fe (Fe2+) concentration.FRO2gene expression and ferric chelate reductase (FC-R) activity were also lower in chlorotic samples, whileHA1andIRT1were more induced. Despite similar apoplasmic pH, K+/Ca2+was higher in chlorotic leaves, and both citrate and malate concentrations in total tissue and apoplast fluid were lower.Conclusion(1) The rootstock influences Fe acquisition system in the leaf; (2) the increased sensitivity to Fe-deficiency as revealed by chlorosis and decreased biomass, was correlated with lower FC-R activity and lower organic acid level in leaf cells, which could cause a decreased Fe mobility and trigger other Fe-stress responses in this organ to enhance acidification and Fe uptake inside cells; and (3) the chlorosis paradox phenomenon in citrus likely occurs as a combination of a marked FC-R activity impairment in the leaf and the strong growth inhibition in this organ.

scholarly journals Unexpected Link between Iron and Drug Resistance of Candida spp.: Iron Depletion Enhances Membrane Fluidity and Drug Diffusion, Leading to Drug-Susceptible Cells

2006 ◽  
Vol 50 (11) ◽  
pp. 3597-3606 ◽  
Author(s):  
Tulika Prasad ◽  
Aparna Chandra ◽  
Chinmay K. Mukhopadhyay ◽  
Rajendra Prasad
Keyword(s):  
Multidrug Resistance ◽  
Membrane Fluidity ◽  
Iron Uptake ◽  
Efflux Pump ◽  
Disulfonic Acid ◽  
Candida Spp ◽  
Copper Transporter ◽  
Iron Depletion ◽  
Cellular Iron ◽  
Increased Sensitivity

ABSTRACT Inthis study, we show that iron depletion in Candida albicans with bathophenanthrolene disulfonic acid and ferrozine as chelators enhanced its sensitivity to several drugs, including the most common antifungal, fluconazole (FLC). Several other species of Candida also displayed increased sensitivity to FLC because of iron restriction. Iron uptake mutations, namely,Δ ftr1 and Δftr2, as well as the copper transporter mutation Δccc2, which affects high-affinity iron uptake in Candida, produced increased sensitivity to FLC compared to that of the wild type. The effect of iron depletion on drug sensitivity appeared to be independent of the efflux pump proteins Cdr1p and Cdr2p. We found that iron deprivation led to lowering of membrane ergosterol by 15 to 30%. Subsequently, fluorescence polarization measurements also revealed that iron-restricted Candida cells displayed a 29 to 40% increase in membrane fluidity, resulting in enhanced passive diffusion of the drugs. Northern blot assays revealed that the ERG11 gene was considerably down regulated in iron-deprived cells, which might account for the lowered ergosterol content. Our results show a close relationship between cellular iron and drug susceptibilities of C. albicans. Considering that multidrug resistance is a manifestation of multifactorial phenomena, the influence of cellular iron on the drug susceptibilities of Candida suggests iron as yet another novel determinant of multidrug resistance.

scholarly journals MOS1 Osmosensor of Metarhizium anisopliae Is Required for Adaptation to Insect Host Hemolymph

2007 ◽  
Vol 7 (2) ◽  
pp. 302-309 ◽  
Author(s):  
Chengshu Wang ◽  
Zhibing Duan ◽  
Raymond J. St. Leger
Keyword(s):  
Osmotic Pressure ◽  
Stress Responses ◽  
Metarhizium Anisopliae ◽  
Turgor Pressure ◽  
Adaptor Proteins ◽  
Reverse Transcription Pcr ◽  
Oxidative Stresses ◽  
Hyphal Bodies ◽  
Increased Sensitivity ◽  
Src Homology

ABSTRACT Entomopathogenic fungi such as Metarhizium anisopliae infect insects by direct penetration of the cuticle, after which the fungus adapts to the high osmotic pressure of the hemolymph and multiplies. Here we characterize the M. anisopliae Mos1 gene and demonstrate that it encodes the osmosensor required for this process. MOS1 contains transmembrane regions and a C-terminal Src homology 3 domain similar to those of yeast osmotic adaptor proteins, and homologs of MOS1 are widely distributed in the fungal kingdom. Reverse transcription-PCR demonstrated that Mos1 is up-regulated in insect hemolymph as well as artificial media with high osmotic pressure. Transformants containing an antisense vector directed to the Mos1 mRNA depleted transcript levels by 80%. This produced selective alterations in regulation of genes involved in hyphal body formation, cell membrane stiffness, and generation of intracellular turgor pressure, suggesting that these processes are mediated by MOS1. Consistent with a role in stress responses, transcript depletion of Mos1 increased sensitivity to osmotic and oxidative stresses and to compounds that interfere with cell wall biosynthesis. It also disrupted developmental processes, including formation of appressoria and hyphal bodies. Insect bioassays confirmed that Mos1 knockdown significantly reduces virulence. Overall, our data show that M. anisopliae MOS1 mediates cellular responses to high osmotic pressure and subsequent adaptations to colonize host hemolymph.

scholarly journals Solvent Stress Response of the Denitrifying Bacterium “Aromatoleum aromaticum” Strain EbN1

2008 ◽  
Vol 74 (8) ◽  
pp. 2267-2274 ◽  
Author(s):  
Kathleen Trautwein ◽  
Simon Kühner ◽  
Lars Wöhlbrand ◽  
Thomas Halder ◽  
Kenny Kuchta ◽  
...  
Keyword(s):  
Stress Responses ◽  
Aromatic Compounds ◽  
Gel Electrophoresis ◽  
Physiological Responses ◽  
Dry Weight ◽  
Anaerobic Growth ◽  
Solvent Concentration ◽  
Denitrifying Bacterium ◽  
Aromatic Substrates ◽  
Difference Gel Electrophoresis

ABSTRACT The denitrifying betaproteobacterium “Aromatoleum aromaticum” strain EbN1 degrades several aromatic compounds, including ethylbenzene, toluene, p-cresol, and phenol, under anoxic conditions. The hydrophobicity of these aromatic solvents determines their toxic properties. Here, we investigated the response of strain EbN1 to aromatic substrates at semi-inhibitory (about 50% growth inhibition) concentrations under two different conditions: first, during anaerobic growth with ethylbenzene (0.32 mM) or toluene (0.74 mM); and second, when anaerobic succinate-utilizing cultures were shocked with ethylbenzene (0.5 mM), toluene (1.2 mM), p-cresol (3.0 mM), and phenol (6.5 mM) as single stressors or as a mixture (total solvent concentration, 2.7 mM). Under all tested conditions impaired growth was paralleled by decelerated nitrate-nitrite consumption. Additionally, alkylbenzene-utilizing cultures accumulated poly(3-hydroxybutyrate) (PHB) up to 10% of the cell dry weight. These physiological responses were also reflected on the proteomic level (as determined by two-dimensional difference gel electrophoresis), e.g., up-regulation of PHB granule-associated phasins, cytochrome cd1 nitrite reductase of denitrification, and several proteins involved in oxidative (e.g., SodB) and general (e.g., ClpB) stress responses.

Regulation of growth and differential tissue dry mass accumulation by Citrus grandis, Poncirus trifoliata and their F1 under salinized and non-salinized environments

2000 ◽  
Vol 27 (1) ◽  
pp. 27 ◽  
Author(s):  
Ilhami Tozlu ◽  
Gloria A. Moore ◽  
Charles L. Guy
Keyword(s):  
Salinity Tolerance ◽  
Mass Production ◽  
Fine Root ◽  
Dry Weight ◽  
Dry Mass ◽  
Poncirus Trifoliata ◽  
Initial Growth ◽  
Ion Content ◽  
Average Growth ◽  
Leaf Tissues

Salt stress responses of C. grandis L. (Osb.), P. trifoliata (L.) Raf. and their F 1 were investi-gated. Growth, growth rates, as well as leaf, stem, structural root (> 2 mm diameter), fine root (≤ 2mm diameter) and whole plant dry masses were determined for the three genotypes tested in 0, 40 and 80 mМ NaCl environments for 20 weeks. P. trifoliata and C. grandis were phenotypically distinct and their F1 had features that were a combination of both parents. The different growth habits resulted in significant differences between the net growth and growth ratios ([net growth / initial growth] × 100) of the three genotypes and between control and salinized plants within each genotype. The average growth and dry weights of nearly all tissues were reduced in salinized plants compared to those of control plants. The exceptions were the fine roots of P. trifoliata at both salinities and of the F1 plants at 40 mМ NaCl. The 40 mМ NaCl treatment stimulated fine root production in P. trifoliata plants, significantly increasing dry weight by 30% compared to control plants. Average shoot dry weight reduction was greatest in C. grandis and least in P. trifoliata in the 40 mМ NaCl treatment. While leaf tissues of P. trifoliata were the most sensitive to salinity, root tissues were the most sensitive in C. grandis. To avoid salt accumulation, P trifoliata plants increased root dry mass production while C. grandis plants increased leaf mass production. These traits appeared to be heritable, since the F1 plants displayed responses intermediate to its parents leading to increased salinity tolerance. We suggest that not only ion content of leaf tissues, but ion content and mass production of all tissues should be considered when the salinity tolerance of Citrus and related genera is characterized.

scholarly journals Enhancement of Drought Tolerance in Trifoliate Orange by Mycorrhiza: Changes in Root Sucrose and Proline Metabolisms

2018 ◽  
Vol 46 (1) ◽  
pp. 270-276 ◽  
Author(s):  
Fei ZHANG ◽  
Jia-Dong HE ◽  
Qiu-Dan NI ◽  
Qiang-Sheng WU ◽  
Ying-Ning ZOU
Keyword(s):  
Drought Tolerance ◽  
Mycorrhizal Fungi ◽  
Water Status ◽  
Lateral Roots ◽  
Arbuscular Mycorrhizal ◽  
Dry Weight ◽  
Sucrose Phosphate Synthase ◽  
Poncirus Trifoliata ◽  
Trifoliate Orange ◽  
Am Symbiosis

Sucrose and proline metabolisms are often associated with drought tolerance of plants. This study was conducted to investigate the effects of two arbuscular mycorrhizal fungi (AMF) species (Funneliformis mosseae and Paraglomus occultum) on root biomass, lateral root number, root sucrose and proline metabolisms in trifoliate orange (Poncirus trifoliata) seedlings under well-watered (WW) or drought stress (DS). All the AMF treatments significantly increased root dry weight, taproot length, and the number of lateral roots in 1st, 2nd, and 3rd class under WW and DS. Mycorrhizal seedlings conferred considerably higher fructose and glucose concentrations but lower sucrose accumulation, regardless of soil water status. Under DS, F. mosseae treatment significantly increased root sucrose synthase (SS, degradative direction) and sucrose phosphate synthase (SPS) activity but deceased root acid invertase (AI) and neutral invertase (NI) activity, and P. occultum inoculation markedly increased root AI, NI, SS, and SPS activities. AMF treatments led to a lower proline accumulation in roots, in company with lower activities of Δ1-pyrroline-5-carboxylate synthetase (P5CS), δ-ornithine aminotransferase (OAT), Δ1-pyrroline-5-carboxylate reductase (P5CR), and proline dehydrogenase (ProDH) in roots. It appears that the AM symbiosis induced greater root development and sucrose and proline metabolisms to adapt DS.

The ferric iron uptake regulator (Fur) from the extreme acidophile Acidithiobacillus ferrooxidans

Microbiology ◽  
2005 ◽  
Vol 151 (6) ◽  
pp. 2005-2015 ◽  
Author(s):  
R. Quatrini ◽  
C. Lefimil ◽  
D. S. Holmes ◽  
E. Jedlicki
Keyword(s):  
Gene Expression ◽  
Stress Responses ◽  
Acidithiobacillus Ferrooxidans ◽  
Iron Uptake ◽  
Ferric Iron ◽  
Sequence Similarity ◽  
Cross Reactivity ◽  
Mobility Shift ◽  
E Coli ◽  
Protein Levels

Acidithiobacillus ferrooxidans is a Gram-negative bacterium that lives at pH 2 in high concentrations of soluble ferrous and ferric iron, making it an interesting model for understanding the biological mechanisms of bacterial iron uptake and homeostasis in extremely acid conditions. A candidate fur AF (Ferric Uptake Regulator) gene was identified in the A. ferrooxidans ATCC 23270 genome. FurAF has significant sequence similarity, including conservation of functional motifs, to known Fur orthologues and exhibits cross-reactivity to Escherichia coli Fur antiserum. The fur AF gene is able to complement fur deficiency in E. coli in an iron-responsive manner. FurAF is also able to bind specifically to E. coli Fur regulatory regions (Fur boxes) and to a candidate Fur box from A. ferrooxidans, as judged by electrophoretic mobility shift assays. FurAF represses gene expression from E. coli Fur-responsive promoters fiu and fhuF when expressed at high protein levels. However, it increases gene expression from these promoters at low concentrations and possibly from other Fur-regulated promoters involved in iron-responsive oxidative stress responses.

Growth and development at cold-hardening temperatures. Pigment and benzoquinone accumulation in winter rye

1985 ◽  
Vol 63 (4) ◽  
pp. 716-721 ◽  
Author(s):  
Marianna Krol ◽  
Norman P. A. Huner
Keyword(s):  
Leaf Area ◽  
Fold Increase ◽  
Dry Weight ◽  
Cold Hardening ◽  
Carotenoid Content ◽  
Winter Rye ◽  
Warm Temperature ◽  
Leaf Ontogeny ◽  
Unit Leaf ◽  
Area Basis

Accumulation of chlorophyll, the carotenoids (β-carotene, lutein, violaxanthin, and neoxanthin), and the benzoquinones (plastoquinone A and α-tocopherol) were monitored in 'Puma' rye as a function of leaf ontogeny at warm and cold-hardening temperatures. Although the kinetics of accumulation differed among the leaves of warm-grown plants, the initial and maximum levels of the pigments and benzoquinones expressed on a leaf area basis did not differ significantly among the first four leaves of the main culm. In contrast, the third and fourth leaf of cold-grown plants, which developed completely at the low temperature, generally exhibited initial and maximum pigment and benzoquinone levels 60–300% greater than was observed for leaf 1 and 2 of cold-grown plants, which were completely or partially developed at the warm temperature regime. This resulted in pigment and benzoquinone levels which were 1.6- to 3-fold greater in the plants grown at cold-hardening temperatures than those grown at the warm temperature, when expressed on a per unit leaf area basis. However, when pigment accumulation was calculated on a chlorophyll basis, the benzoquinone content of leaves that developed solely at cold-hardening temperatures exhibited a 1.7-fold increase over the same leaves developed at warm temperatures. Carotenoids did not exhibit this trend. Calculations based on chlorophyll/carotenoid content and dry weight accumulation indicated that leaves that were developed at cold-hardening temperatures appeared to produce more dry matter per unit of photosynthetic pigments than the same leaves that were developed at nonhardening temperatures.

scholarly journals Pemberian Pupuk Silika Cair untuk Meningkatkan Pertumbuhan, Hasil, dan Toleransi Kekeringan Padi Sawah

2018 ◽  
Vol 46 (2) ◽  
pp. 153 ◽  
Author(s):  
Sugiyanta , ◽  
I Made Dharmika ◽  
Dan Dedeh Siti Mulyani
Keyword(s):  
Field Experiment ◽  
Soil Water ◽  
Stress Responses ◽  
Oryza Sativa L ◽  
Block Design ◽  
Dry Weight ◽  
Fertilizer Application ◽  
Greenhouse Experiment ◽  
Growth And Yield ◽  
Shoot Dry Weight

ABSTRACT<br />    <br />As one of the silica (Si) accumulator, rice (Oryza sativa L.) requires large amounts of silica for growth. This study aimed to determine the effect of liquid silica fertilizer application on lowland rice growth and yield, and its roles in drought stress responses. The experiments were conducted at Sawah Baru rice field and Cikabayan Greenhouse Experiment Station, IPB, Bogor during the period of January to May 2016. The field experiment was set up in a randomized complete block design with 7 treatments and three replications. The greenhouses experiment was arranged in a split-plot randomized block design with 3 replications. The main plots were 5 levels of liquid silica fertilizer application, while the subplot was 5 level of various soil water contents. The results of the field experiment showed that the application of liquid silica fertilizer increased rice shoot dry weight, total and productive tiller numbers, and yield per plant, but did not increase yield per hectare. Meanwhile at greenhouse experiment, it showed that the use of liquid silica fertilizer reduced the number of rice stomata, but did not increase cuticle thickness and grain yield per plant. Silica application was not effective to alter drought in rice.<br /><br />Keywords: IPB 3S, silica fertilizer, soil water content, water use efficiency   <br /><br />

scholarly journals Modification of Petunia seedling Carbohydrate Partitioning by Irradiance

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1073d-1073
Author(s):  
David F. Grarper ◽  
Will Healy
Keyword(s):  
Leaf Area ◽  
Oxygen Evolution ◽  
Petunia Hybrida ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Invertase Activity ◽  
Photon Flux ◽  
Total Carbohydrate ◽  
Leaf Stage ◽  
Area Basis

Petunia × hybrida Villm. `Red Flash' plants were irradiated for either 10 or 20 mol day1 photosynthetic photon flux (PPF) in growth chambers using one of the following treatments: 175 μmol m-2 s-1 for 16 h, 350 μmol m-2 s-1 for 8 or 16 h or 350 μmol m-2 s-1 for 8 h plus 8 h incandescent day extension (5 μmol m-2 s-1 PPF). These four treatments were designed to examine the effects of increased peak and total daily integrated PPF as well as increased photosynthetic (Pn) period and photoperiod resulting from supplemental irradiance treatment of seedlings. Previous seedling petunia research indicated a greater response to supplemental lighting during expansion of the second true leaf. Therefore, seedlings were sampled for analysis at the two leaf stage and also later at the four leaf stage to examine effects at a later stage of growth.Increasing total integrated PPF increased total carbohydrate production, seedling dry weight, rate of seedling growth, and acid invertase activity once the seedlings reached the two leaf stage. Increasing total PPF resulted in greater partitioning into ethanol soluble sugars rather than starch at the two leaf stage. Increasing the photoperiod only, with an incandescent day extension treatment, reduced total carbohydrate production at the two leaf stage.Maximal oxygen evolution was observed when seedlings received 350 μmolm-2s-1 for 8 h when expressed on a leaf area or dry weight basis. The use of an 8 h day extension treatment to extend the photoperiod from 8 to 16 h resulted in the lowest rates of oxygen evolution on a leaf area basis.

scholarly journals Nitrogen Nutrition of Containerized Citrus Nursery Plants

1994 ◽  
Vol 119 (2) ◽  
pp. 195-201 ◽  
Author(s):  
B.E. Maust ◽  
J.G. Williamson
Keyword(s):  
Citrus Sinensis ◽  
Dry Weight ◽  
Leaf Expansion ◽  
Poncirus Trifoliata ◽  
Growth Stages ◽  
The Third ◽  
N Concentration ◽  
Total Plant ◽  
Cleopatra Mandarin ◽  
Critical N Concentration

Experiments were conducted with `Hamlin' orange [Citrus sinensis (L.) Osb.] budded on Cleopatra mandarin (Citrus reticulata Blanco) or Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.] seedling rootstocks to determine minimum container solution N concentrations required for optimum growth and fertilizer uptake efficiency at various growth stages. Plants were fertigated daily with 1 liter of N solution at either 0, 12.5, 25, 50, 100, or 200 mg·liter-1 from NH4NO3 or 0, 3.13, 6.25, 12.5, 25, or 50 mg·liter-1 from NH4NO3 dissolved in a complete nutrient solution, respectively. Percentage of N in the mature plant tissues increased as N concentration in the medium solution increased. Shoot length and leaf area increased as N concentrations increased up to a critical concentration of 15 to 19 mg·liter-1. The critical N concentration for root, shoot, and total plant dry weight was ≈18 mg·liter-1 for `Hamlin'-Cleopatra mandarin nursery plants and 15 mg·liter-1 for `Hamlin'-Carrizo nursery plants. The critical N concentration for relative total plant dry weight accumulation (percentage) for the two experiments was 16.8 mg·liter-1. In a separate experiment, plants were given labeled fertilizer N (FN) (15NH415NO3) at one of five growth stages: A) in the middle of rapid shoot extension of the third flush, B) immediately following the cessation of the third flush shoot extension but during leaf expansion, C) immediately following leaf expansion, D) before the fourth flush, or E) in the middle of rapid shoot extension of the fourth flush. Labeled FN recovery increased during rapid shoot extension of the fourth scion flush compared to the other labeling periods. FN uptake per gram of total plant dry weight was greatest during rapid shoot extension (A and E) and lowest during the intermediate labeling periods (B-D). FN supplied 21% to 22% of the N required for new growth during rapid shoot extension.

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