scholarly journals Microbe-plant interactions between Streptomyces and model agricultural plants – Hordeum vulgare and Lycopersicon esculentum (Microtom)

2019 ◽  
Vol 25 ◽  
pp. 137-141
Author(s):  
H. V. Mutenko ◽  
B. O. Ostash ◽  
M. Rothballer ◽  
A. Weiss ◽  
M. Schmid ◽  
...  
Keyword(s):  
Hordeum Vulgare ◽  
Lycopersicon Esculentum ◽  
Positive Influence ◽  
Low Molecular Weight ◽  
Plant Interactions ◽  
Experimental Conditions ◽  
Streptomyces Ghanaensis ◽  
Root And Shoot Growth ◽  
Agricultural Plants ◽  
Different Strains

Aim. Microbe-plant interactions (MPI) constitute an important aspect of ecology because of their significant influence on plant’s ability to withstand abiotic stress and infection. In comparison to proteobacteria and bacilli, the roles of streptomycetes in MPI remain poorly studied. Here, we elucidate some aspects of MPI between two model plant species, Hordeum vulgare and Lycopersicon esculentum, and several strains of Streptomyces lividans 1326 and S. ghanaensis ATCC14672. Methods. Microbiology, microscopy and molecular genetics were combined to reveal the MPI. Results. We demonstrate the colonization of H. vulgare and L. esculentum roots by different strains of S. ghanaensis deficient in production of either the antibiotic moenomycin or signaling molecule of the γ-butyrolactone type. The treatment of H. vulgare seeds with S. lividans spores increased the root biomass. Plants treated with 1,4-butyrolactone had no positive influence on plants, at milimolar concentrations this compound inhibited the root and shoot growth of L. esculentum. Conclusions. Roots of two mono- and dicot plants are colonized by Streptomyces; reporter gene uidA is useful to monitor the colonization. Under our experimental conditions the ability to colonize plants by streptomycetes was not affected by the deficiency in antibiotic or butenolide production. Keywords: Streptomyces ghanaensis, moenomycinA, low-molecular weight signal compounds, root colonization.

scholarly journals Competition-free gaps are essential for the germination and recruitment of alpine species along an elevation gradient in the European Alps

Alpine Botany ◽  
2021 ◽  
Author(s):  
Vera Margreiter ◽  
Janette Walde ◽  
Brigitta Erschbamer
Keyword(s):  
Vegetation Cover ◽  
Seedling Recruitment ◽  
Environmental Control ◽  
Elevation Gradient ◽  
European Alps ◽  
Plant Interactions ◽  
Experimental Conditions ◽  
Positive Effects ◽  
Seed Sowing ◽  
Plant Plant

AbstractSeed germination and seedling recruitment are key processes in the life cycle of plants. They enable populations to grow, migrate, or persist. Both processes are under environmental control and influenced by site conditions and plant–plant interactions. Here, we present the results of a seed-sowing experiment performed along an elevation gradient (2000–2900 m a.s.l.) in the European eastern Alps. We monitored the germination of seeds and seedling recruitment for 2 years. Three effects were investigated: effects of sites and home sites (seed origin), effects of gaps, and plant–plant interactions. Seeds of eight species originating from two home sites were transplanted to four sites (home site and ± in elevation). Seed sowing was performed in experimentally created gaps. These gap types (‘gap + roots’, ‘neighbor + roots’, and ‘no-comp’) provided different plant–plant interactions and competition intensities. We observed decreasing germination with increasing elevation, independent of the species home sites. Competition-released gaps favored recruitment, pointing out the important role of belowground competition and soil components in recruitment. In gaps with one neighboring species, neutral plant–plant interactions occurred (with one exception). However, considering the relative vegetation cover of each experimental site, high vegetation cover resulted in positive effects on recruitment at higher sites and neutral effects at lower sites. All tested species showed intraspecific variability when responding to the experimental conditions. We discuss our findings considering novel site and climatic conditions.

scholarly journals The influence of temperature on the absorption of water by seeds of hordeum vulgare in relation to the temperature coefficient of chemical change

1912 ◽  
Vol 85 (582) ◽  
pp. 546-553 ◽  
Keyword(s):  
Hordeum Vulgare ◽  
Aqueous Solutions ◽  
Temperature Coefficient ◽  
Chemical Change ◽  
Experimental Conditions ◽  
Influence Of Temperature ◽  
Suitable Medium ◽  
Influence Of Temperature On

Attention has previously been directed by one of us to the existence of a differential septum enclosing the seeds of Hordeum (barley). When the seeds are immersed in aqueous solutions of most electrolytes, and of many non-electrolytes, this covering behaves as a very efficient differential septum, water alone entering the seeds under the attractive influence of the finely granulated contents. The rate at which the water enters is considerably affected if substances are dissolved in it, being increased by some and diminished by others; it is also markedly dependent on the temperature of the water or solution in which the seeds are immersed. Variations of the rate at which water enters with alterations of the experimental conditions are presumably due mainly to changes in the water, and the seeds of Hordeum would thus appear to be a very suitable medium for the investigation of the nature of the changes produced in water by the presence of dissolved substances or by alterations of temperature.

scholarly journals Utilization of Non-Living Microalgae Biomass from Two Different Strains for the Adsorptive Removal of Diclofenac from Water

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1401 ◽  
Author(s):  
Ricardo Coimbra ◽  
Carla Escapa ◽  
Nadyr Vázquez ◽  
Guillermo Noriega-Hevia ◽  
Marta Otero
Keyword(s):  
Activated Carbon ◽  
Experimental Conditions ◽  
Biomass Waste ◽  
Adsorptive Removal ◽  
Microalgae Biomass ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Equilibrium Concentrations ◽  
Different Strains ◽  
Synechocystis Sp

In the present work, the adsorptive removal of diclofenac from water by biosorption onto non-living microalgae biomass was assessed. Kinetic and equilibrium experiments were carried out using biomass of two different microalgae strains, namely Synechocystis sp. and Scenedesmus sp. Also, for comparison purposes, a commercial activated carbon was used under identical experimental conditions. The kinetics of the diclofenac adsorption fitted the pseudo-second order equation, and the corresponding kinetic constants indicating that adsorption was faster onto microalgae biomass than onto the activated carbon. Regarding the equilibrium results, which mostly fitted the Langmuir isotherm model, these pointed to significant differences between the adsorbent materials. The Langmuir maximum capacity (Qmax) of the activated carbon (232 mg∙g−1) was higher than that of Scenedesmus sp. (28 mg∙g−1) and of Synechocystis sp. (20 mg∙g−1). In any case, the Qmax values determined here were within the values published in the recent scientific literature on the utilization of different adsorbents for the removal of diclofenac from water. Still, Synechocystis sp. showed the largest KL fitted values, which points to the affinity of this strain for diclofenac at relative low equilibrium concentrations in solution. Overall, the results obtained point to the possible utilization of microalgae biomass waste in the treatment of water, namely for the adsorption of pharmaceuticals.

Effects of absence positioning of unknown product ingredients on consumer evaluations

2018 ◽  
Vol 52 (9/10) ◽  
pp. 2128-2150
Author(s):  
Timucin Ozcan ◽  
Ahmet M. Hattat ◽  
Michael Hair
Keyword(s):  
Regulatory Focus ◽  
Initial Study ◽  
Positive Influence ◽  
Mediation Effect ◽  
Amazon Mechanical Turk ◽  
Initial Attempt ◽  
Experimental Conditions ◽  
Consumer Evaluations ◽  
Content Type ◽  
Study Results

Purpose This paper aims to investigate the effectiveness of positioning unknown ingredients either with the presence or absence of framing; both are common in marketplace (e.g. Secret® deodorant visibly claims “aluminum chlorohydrate” while Crystal® promotes “no aluminum chlorohydrate”). Design/methodology/approach The authors used three scenario-based experiments. The participants were recruited through Amazon Mechanical Turk online panel and randomly assigned to a variety of experimental conditions. Findings Initial study results show that consumers have more positive evaluations and purchase intentions for absence positioning than presence positioning, because absence positioning induces greater perceptions of protection. In the second study, these results are extended using multiple ingredients, along with competitor products; they show that absence positioning leads to better evaluations than presence positioning and replicate the mediation effect that was found earlier. In the final study, through manipulating participants’ regulatory focus, the authors show that absence-positioned ingredients have a higher choice share when consumers are in the prevention mindset. Conversely, when customers are in promotion mindset and looking for better performance, presence positioning of ingredients seems to have higher choice shares. Research limitations/implications The research has implications for product development, promotions, labeling and packaging, showing the positive influence of absence positioning of unknown ingredients. Practical implications Marketers may emphasize the absence of unknown ingredients in their products instead of following a strategy that highlights the inclusion of them. Originality/value To the authors’ extant knowledge, this research is an initial attempt to understand how consumers react to promotion of product ingredients. In addition, it contributes to the literature in unknown attributes by showing that absence positioning of certain types of ingredients is perceived better than presence framing of them.

scholarly journals Genotypic differences in root and shoot growth of barley (Hordeum vulgare L.) grown under different salinity levels

Hereditas ◽  
2010 ◽  
Vol 147 (3) ◽  
pp. 114-122 ◽  
Author(s):  
H. Bchini ◽  
M. Ben Naceur ◽  
R. Sayar ◽  
H. Khemira ◽  
L. Ben Kaab-Bettaeïb
Keyword(s):  
Hordeum Vulgare ◽  
Shoot Growth ◽  
Genotypic Differences ◽  
Hordeum Vulgare L ◽  
Root And Shoot Growth ◽  
Salinity Levels

scholarly journals Radiometric studies of mycobacterium tuberculosis

1987 ◽  
Vol 29 (1) ◽  
pp. 18-25
Author(s):  
Edwaldo E. Camargo ◽  
Judith A. Kertcher ◽  
Marianne F. Chen ◽  
Patricia Charache ◽  
Henry N. Wagner Jr
Keyword(s):  
Palmitic Acid ◽  
Lauric Acid ◽  
Bacterial Suspension ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Experimental Conditions ◽  
Vitro Assay ◽  
Minimal Inhibitory Concentrations ◽  
Different Strains

An in vitro assay system that included automated radiometric quantification of 14CO2 released as a result of oxidation of 14C- substrates was applied for studying the metabolic activity of M. tuberculosis under various experimental conditions. These experiments included the study of a) mtabolic pathways, b) detection times for various inoculum sizes, c) effect of filtration on reproducibility of results, d) influence of stress environment e) minimal inhibitory concentrations for isoniazid, streptomycin, ethambutol and rifampin, and f) generation times of M. tuberculosis and M. bovis. These organisms were found to metabolize 14C-for-mate, (U-14C) acetate, (U-14C) glycerol, (1-14C) palmitic acid, 1-14C) lauric acid, (U-14C) L-malic acid, (U-14C) D-glucose, and (U-14C) D-glucose, but not (1-14C) L-glucose, (U-14C) glycine, or (U-14C) pyruvate to 14CO2. By using either 14C-for-mate, (1-14C) palmitic acid, or (1-14C) lauric acid, 10(7) organisms/vial could be detected within 24 48 hours and as few as 10 organisms/vial within 16-20 days. Reproducible results could be obtained without filtering the bacterial suspension, provided that the organisms were grown in liquid 7H9 medium with 0.05% polysorbate 80 and homogenized prior to the study. Drugs that block protein synthesis were found to have lower minimal inhibitory concentrations with the radiometric method when compared to the conventional agar dilution method. The mean generation time obtained for M. bovis and different strains of M. tuberculosis with various substrates was 9 ± 1 hours.

Napropamide Uptake, Transport, and Metabolism in Corn (Zea mays) and Tomato (Lycopersicon esculentum)

Weed Science ◽  
1981 ◽  
Vol 29 (6) ◽  
pp. 697-703 ◽  
Author(s):  
Michael Barrett ◽  
Floyd M. Ashton
Keyword(s):  
Zea Mays ◽  
Lycopersicon Esculentum ◽  
Root Growth ◽  
Shoot Growth ◽  
Root Tissue ◽  
Tomato Root ◽  
Corn Roots ◽  
Tomato Roots ◽  
Absorption Studies ◽  
Root And Shoot Growth

Napropamide [2-(α-napthoxy)-N,N-diethylpropionamide] inhibited root and shoot growth in corn (Zea maysL. ‘NC+ 59’) and tomato (Lycopersicon esculentumMill. ‘Niagara VF315’) seedlings. Shoot growth was reduced less than root growth in both species. Corn roots were approximately 10 times more sensitive to napropamide than were tomato roots. Translocation of napropamide from the roots to the shoot of tomato occurred within 0.5 h and followed an apoplastic pattern. Little movement of napropamide from the roots to the shoots occurred in corn. Metabolism of napropamide was not evident in either species during an 8-h exposure. Absorption studies showed that total napropamide levels were 60% higher in corn root tissue than in tomato root tissue. The greater napropamide content in the corn roots was associated with a tightly bound fraction of the total napropamide influx.

scholarly journals Transmission of the Bean-Associated Cytorhabdovirus by the Whitefly Bemisia tabaci MEAM1

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1028
Author(s):  
Bruna Pinheiro-Lima ◽  
Rita C. Pereira-Carvalho ◽  
Dione M. T. Alves-Freitas ◽  
Elliot W. Kitajima ◽  
Andreza H. Vidal ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Control Strategies ◽  
Genomic Data ◽  
Plant Viruses ◽  
Asia Minor ◽  
Plant Interactions ◽  
Experimental Conditions ◽  
Lower Efficiency ◽  
Viral Particles ◽  
Pathogenicity Tests

The knowledge of genomic data of new plant viruses is increasing exponentially; however, some aspects of their biology, such as vectors and host range, remain mostly unknown. This information is crucial for the understanding of virus–plant interactions, control strategies, and mechanisms to prevent outbreaks. Typically, rhabdoviruses infect monocot and dicot plants and are vectored in nature by hemipteran sap-sucking insects, including aphids, leafhoppers, and planthoppers. However, several strains of a potentially whitefly-transmitted virus, papaya cytorhabdovirus, were recently described: (i) bean-associated cytorhabdovirus (BaCV) in Brazil, (ii) papaya virus E (PpVE) in Ecuador, and (iii) citrus-associated rhabdovirus (CiaRV) in China. Here, we examine the potential of the Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) to transmit BaCV, its morphological and cytopathological characteristics, and assess the incidence of BaCV across bean producing areas in Brazil. Our results show that BaCV is efficiently transmitted, in experimental conditions, by B. tabaci MEAM1 to bean cultivars, and with lower efficiency to cowpea and soybean. Moreover, we detected BaCV RNA in viruliferous whiteflies but we were unable to visualize viral particles or viroplasm in the whitefly tissues. BaCV could not be singly isolated for pathogenicity tests, identification of the induced symptoms, and the transmission assay. BaCV was detected in five out of the seven states in Brazil included in our study, suggesting that it is widely distributed throughout bean producing areas in the country. This is the first report of a whitefly-transmitted rhabdovirus.

scholarly journals Galloylglucoses of low molecular weight as mordant in electron microscopy. I. Procedure, and evidence for mordanting effect.

1976 ◽  
Vol 70 (3) ◽  
pp. 608-621 ◽  
Author(s):  
N Simionescu ◽  
M Simionescu
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Tannic Acid ◽  
Sodium Borohydride ◽  
Low Molecular Weight ◽  
High Contrast ◽  
Experimental Conditions ◽  
Complex Effect ◽  
Tissue Contrast ◽  
Tissue Specimens

Gallotannin, consisting mainly of low molecular weight esters such as penta- and hexagalloylglucoses (commercially available as tannic acid produced from Turkish nutgall), can be used for increasing and diversifying tissue contrast in electron microscopy. When applied on tissue specimens previously fixed by conventional methods (aldehydes and OsO4), the low molecular weight galloylglucoses (LMGG) penetrate satisfactorily the cells and induce general high contrast with fine delineation of extra- and intracellular structures, especially membranes. In some features, additional details of their intimate configuration are revealed. Various experimental conditions tested indicate that the LMGG display a complex effect on fixed tissues: they act primarily as a mordant between osmium-treated structures and lead, and concomitantly stabilize some tissue components against extraction incurred during dehydration and subsequent processing. Experiments with aldehyde blocking reagents (sodium borohydride and glycine) suggested that the LMGG mordanting effect is not dependent on residual aldehydes groups in tissues.

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