Changes in membrane potential of intact soybean root elongation zone cells induced by Azospirillum brasilense

1991 ◽  
Vol 37 (12) ◽  
pp. 958-963 ◽  
Author(s):  
Yoav Bashan
Keyword(s):  
Membrane Potential ◽  
Azospirillum Brasilense ◽  
Physiological Status ◽  
Bacterial Cells ◽  
Elongation Zone ◽  
Root Cells ◽  
Soybean Seedlings ◽  
Live Bacteria ◽  
Soybean Plants ◽  
High Level

Inoculation of soybean seedlings with Azospirillum brasilense significantly reduced the membrane potential of root cells and made it less negative. The effect was most pronounced in the cells of the elongation zone. Three A. brasilense strains reduced the membrane potential of elongation zone cells to a similar extent. Dead cells or cells of an associative nonbeneficial Pseudomonas species caused no effect. Reduction of membrane potential of root cells was directly related to the physiological status of the bacterial cells. Active bacteria reduced the membrane potential. Stressed bacteria, i.e., bacteria exposed to either starvation, anaerobic conditions, or a high level of streptomycin prior to inoculation, failed to affect membrane potential. Continuous perfusion of the roots immediately after inoculation, while maintaining the bacterial cells surrounding the roots, cancelled the effect of live bacteria on membrane potential. Regardless of bacterial cell treatment or effect on membrane potential of root cells, root colonization levels of all A. brasilense strains were similar throughout all experiments. In addition, all strains positively affect the growth of soybean seedlings. It is suggested that inoculation of soybean plants with live A. brasilense strains, possessing an active metabolism, reduced the membrane potential of root cells probably through the release of an, as yet, unidentified bacterial signal(s). Key words: Azospirillum, beneficial bacteria, Glycine max, membrane potential, plant–bacteria interaction, rhizosphere bacteria, soybean.

Short exposure to Azospirillum brasilense Cd inoculation enhanced proton efflux of intact wheat roots

1990 ◽  
Vol 36 (6) ◽  
pp. 419-425 ◽  
Author(s):  
Yoav Bashan
Keyword(s):  
Azospirillum Brasilense ◽  
Optimal Level ◽  
Rhizosphere Bacteria ◽  
Short Exposure ◽  
Physiological Status ◽  
Bacterial Cells ◽  
Proton Efflux ◽  
Proton Extrusion ◽  
Wheat Roots ◽  
Wheat Seedlings

Inoculation of wheat seedlings with Azospirillum brasilense Cd significantly increased the proton efflux of the roots 5 h after inoculation compared with noninoculated plants. Removal of the bacterial cells from the root surface 2, 4, or 10 h after inoculation did not affect proton extrusion, which remained similar to the proton efflux of inoculated roots with a permanent A. brasilense Cd population. Proton efflux from roots after short exposure to A. brasilense Cd was directly related to the inoculation level and to the physiological status of the bacterial cells. Active bacteria, at an optimal level for inoculation (105–107 cfu∙mL−1), produced the most proton extrusion from roots. Stressed bacteria, i.e., bacteria exposed to starvation, 45 °C, anaerobic conditions, or a high level of streptomycin before inoculation, induced smaller but not statistically significant increases in proton efflux. Inoculation with dead A. brasilense Cd cells, cell-wall fragments, or several associative nonbeneficial rhizosphere bacteria belonging to other genera did not enhance the proton efflux compared with noninoculated plants. Continuous perfusion of the nutrient solution of plants while maintaining the bacterial cells in the root vicinity eliminated the proton efflux enhancement caused by A. brasilense Cd. Bacteria, regardless of species or stress conditions, in the absence of plants produced negligible proton efflux. It is suggested that short exposures of wheat roots to live A. brasilense Cd enhanced the proton efflux of roots, probably through the release of an as yet unidentified bacterial signal. Active metabolism of the bacterium is required for this enhancement, which is of a triggering nature. Key words: Azospirillum, beneficial bacteria, plant–bacteria interaction, proton efflux, rhizosphere bacteria, Triticum aestivum, wheat.

Toxic Effect of 2-ethyl (bicyclo[2.2.1] heptane) on Bacterial Cells

2019 ◽  
Vol 35 (6) ◽  
pp. 67-72 ◽  
Author(s):  
I.V. Manukhov ◽  
L.S. Yaguzhinsky ◽  
M.V. Bermeshev ◽  
M.A. Zisman ◽  
V.G. Pevgov ◽  
...  
Keyword(s):  
Toxic Effect ◽  
Atmospheric Oxygen ◽  
Inducible Promoter ◽  
Oxygen Species ◽  
Bacterial Cells ◽  
Unique Identifier ◽  
E Coli ◽  
Lux Biosensors ◽  
High Level ◽  
Ministry Of Higher Education

Toxic effect of 2-ethylnorbornane (2-ethyl(bicyclo[2.2.1]heptane) (EBH)) on bacteria has been studied using the E. coli pRecA-lux and E. coli pKatG- lux cells as lux-biosensors. It was shown that the addition of EBH to the incubation medium leads to death and growth retardation, high level oxidative stress and DNA damage in E. coli cells. It is assumed that the oxidation of EBH with atmospheric oxygen causes the formation of reactive oxygen species in the medium, which makes a major contribution to the toxicity of this substance. biosensor, luciferase, bioluminescence, inducible promoter, PrecA, PkatG The authors are grateful to Stanislav Filippovich Chalkin for the development of interdisciplinary ties in the scientific community. The work was financially supported by the Ministry of Higher Education and Science of Russia (Project Unique Identifier RFMEFI60417X0181, Agreement No. 14.604.21.0181 of 26.09.2017).

scholarly journals SOYBEAN CULTIVATION IN A CROP-LIVESTOCK SYSTEM WITH Azospirillum brasilense INOCULATION

2018 ◽  
Vol 31 (1) ◽  
pp. 1-8
Author(s):  
MARCOS DA SILVA BRUM ◽  
THOMAS NEWTON MARTIN ◽  
VINÍCIUS SANTOS DA CUNHA ◽  
LUIZ FERNANDO TELEKEN GRANDO ◽  
ALEX TAGLIAPIETRA SCHONELL
Keyword(s):  
Azospirillum Brasilense ◽  
Block Design ◽  
Experimental Period ◽  
Height Control ◽  
Grain Productivity ◽  
Randomized Complete Block Design ◽  
Grazing Systems ◽  
Soybean Plants ◽  
Santa Maria ◽  
Livestock System

ABSTRACT The objective of this study was to evaluate the phytomorphological parameters of soybean in a crop-livestock system inoculated with Azospirillum brasilense. The experiment was conducted in Santa Maria, Brazil, for two agricultural years (2 Paper extracted from the doctoral thesis of the first author. 012/2013 and 2013/2014) in a randomized complete block design with three replications. In the winter, the black oat and ryegrass pasture was managed with sheep under different grazing systems: (I) - a conventional grazing (CG) system, where the animals remained in the pasture throughout the experimental period without any pasture height control; (II, III, and IV) - systems with post-grazing pasture heights of 10, 20, and 30 cm, respectively; and (NG) - one control without grazing. All treatments received two nitrogen doses (50 and 100 kg ha-1) and inoculation or no inoculation (A. brasilense). The soybean cultivar BMX Potência RR was sown using no-tillage on 16 November 2012 and 1 December 2013. In each plot, seven rows of plants with spacing of 0.45 m were used, and in four rows, the seeds were inoculated with the bacterium A. brasilense. The phytomorphological variables and grain productivity were evaluated. In a croplivestock system, soybean has better productivity when established on black oat and ryegrass pasture managed with post-grazing pasture heights of between 20 and 30 cm. Areas under conventional grazing in the winter led to smaller soybean plants with lower first and last pod heights. Inoculation with A. brasilense should not be used alone in soybean cultivation.

scholarly journals Induction of the Maize GapC4 Promoter in Transgenic Potato under Anaerobiosis and in Erwinia carotovora-Inoculated Tuber Tissue

1999 ◽  
Vol 12 (3) ◽  
pp. 182-188 ◽  
Author(s):  
Lorenz Bülow ◽  
Uwe Köhler ◽  
Rüdiger Cerff ◽  
Reinhard Hehl ◽  
Klaus Düring
Keyword(s):  
Experimental System ◽  
Erwinia Carotovora ◽  
Transgenic Potato ◽  
Intact Tissue ◽  
Induction Pattern ◽  
Pectolytic Enzymes ◽  
Genes Encoding ◽  
Live Bacteria ◽  
Foreign Genes ◽  
High Level

The induction pattern of the GapC4 promoter from maize in transgenic potato has been analyzed by fusion to the β-glucuronidase (gus) gene. Under anaerobic conditions this promoter confers high level expression not only in leaves, stems, and roots but also in tubers. After inoculation of potato tuber disks with Erwinia carotovora subsp. atroseptica, β-glucuronidase (GUS) activity could be detected in macerated tissue as well as in surrounding intact tissue. In mock controls no induction was detected, ruling out any induction due to an overall limitation in oxygen in the experimental system. In addition, it could be proven that no diffusion of GUS protein from macerated into intact tissue occurred. The promoter was shown to be aerobically induced even in the absence of live bacteria by incubation with purified Erwinia spp. pectolytic enzymes alone. Therefore, promoter induction seems to be mediated by a mobile factor instead of by limitation in oxygen. These results demonstrate that the maize GapC4 promoter is suitable for directing foreign genes encoding antibacterial proteins in transgenic potato.

scholarly journals Co-inoculation with Azospirillum brasilense in soybean cultivars subjected to water déficit

2020 ◽  
Vol 24 (2) ◽  
pp. 89-94 ◽  
Author(s):  
Alessandra M. de L. Naoe ◽  
Joênes M. Peluzio ◽  
Leonardo J. M. Campos ◽  
Lucas K. Naoe ◽  
Roberta A. e Silva
Keyword(s):  
Grain Yield ◽  
Water Deficit ◽  
Bradyrhizobium Japonicum ◽  
Azospirillum Brasilense ◽  
Field Experiments ◽  
Crop Evapotranspiration ◽  
Plant Genotype ◽  
Soybean Cultivars ◽  
Sowing Dates ◽  
Soybean Plants

ABSTRACT This study aimed to verify the effect of co-inoculation, association between Azospirillum brasilense and Bradyrhizobium japonicum bacteria, on soybean plants subjected to water deficit at two sowing dates. Two field experiments were conducted at the Universidade Federal de Tocantins, campus of Palmas, Brazil, in 2016. The experimental design was randomized blocks in a split-split-plot arrangement with four repetitions, where the plots consisted of two irrigation depths (100 and 25% of crop evapotranspiration - ETc), the subplots was composed of two methods of inoculant application (inoculation with Bradyrhizobium japonicum and co-inoculation with Azospirillum brasilense + Bradyrhizobium japonicum) and the sub-subplots comprised two soybean cultivars (TMG 132 and ANTA 82). The cultivars responded differently to the sowing dates. Co-inoculation did not influence grain yield under full irrigation conditions (100% ETc), in neither cultivar evaluated. However, under the water deficit condition (25% ETc), the grain yield of the cultivar TMG 132 increased 77.20%, indicating that there are different responses of interaction between Azospirillum brasilense, plant genotype and sowing dates.

Non-contact Abnormal Physiological Status Detection during Sport and Training

2021 ◽  
Vol 12 (4) ◽  
pp. 0-0
Keyword(s):  
Correlation Energy ◽  
Physiological Parameters ◽  
Physiological Parameter ◽  
Physiological Status ◽  
Monitoring Method ◽  
Energy Entropy ◽  
External Conditions ◽  
High Level ◽  
And Training ◽  
Parameter Monitoring

In sport and training, it is necessary to continue monitoring the physiological parameters of athletes to ensure that they can maintain a high level of competitive state. The previous monitoring physiological status methods mainly are contactable by sensors that are worn on body. This paper adopts a non-contact physiological parameter monitoring method by using imaging photoplethysmography (iPPG). In order to eliminate the noises in iPPG signals, the correlation energy entropy threshold adaptive denoising and variance characterization sereies are introduced to resist the noises from external conditions. The noises are remove by a threshold which is estimated by noise energy entropy. The constructed signals after denoising are used to estimate physiological parameters, such as heart rate and respiratory rate. The experimental results demonstrate that it estimates the physiological parameters better by usng iPPG based physiological parameter monitoring method than previous methods.

scholarly journals Expanded toolbox for directing the biosynthesis of macrocyclic peptides in bacterial cells

2020 ◽  
Vol 11 (24) ◽  
pp. 6202-6208
Author(s):  
Jacob A. Iannuzzelli ◽  
Rudi Fasan
Keyword(s):  
Amino Acids ◽  
Unnatural Amino Acids ◽  
Bacterial Cells ◽  
Macrocyclic Peptides ◽  
Live Bacteria

A new suite of unnatural amino acids is reported for directing the biosynthesis of genetically encoded macrocyclic peptides in live bacteria.

scholarly journals Stuttering: high-level mistranslation in animal and bacterial cells.

1978 ◽  
Vol 75 (3) ◽  
pp. 1091-1095 ◽  
Author(s):  
J. Parker ◽  
J. W. Pollard ◽  
J. D. Friesen ◽  
C. P. Stanners
Keyword(s):  
Bacterial Cells ◽  
High Level

The Interplay between DNA Topology and Accessory Factors in Site-Specific Recombination in Bacteria and their Bacteriophages

2016 ◽  
Vol 99 (4) ◽  
pp. 420-437 ◽  
Author(s):  
Charles J. Dorman ◽  
Marina M. Bogue
Keyword(s):  
Dna Sequences ◽  
Dna Topology ◽  
Life Cycles ◽  
Physiological Status ◽  
Bacterial Cells ◽  
Site Specific ◽  
Site Specific Recombination ◽  
Topological State ◽  
Accessory Factors ◽  
Recombination Reactions

Site-specific recombination is employed widely in bacteria and bacteriophage as a basis for genetic switching events that control phenotypic variation. It plays a vital role in the life cycles of phages and in the replication cycles of chromosomes and plasmids in bacteria. Site-specific recombinases drive these processes using very short segments of identical (or nearly identical) DNA sequences. In some cases, the efficiencies of the recombination reactions are modulated by the topological state of the participating DNA sequences and by the availability of accessory proteins that shape the DNA. These dependencies link the molecular machines that conduct the recombination reactions to the physiological state of the cell. This is because the topological state of bacterial DNA varies constantly during the growth cycle and so does the availability of the accessory factors. In addition, some accessory factors are under allosteric control by metabolic products or second messengers that report the physiological status of the cell. The interplay between DNA topology, accessory factors and site-specific recombination provides a powerful illustration of the connectedness and integration of molecular events in bacterial cells and in viruses that parasitise bacterial cells.

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