scholarly journals Effects of Cry toxins on non-target soil bacteria during a 2-year follow up study

2019 ◽  
Vol 17 (2) ◽  
pp. e0303 ◽  
Author(s):  
Amina Yaqoob ◽  
Ahmad A. Shahid ◽  
Ibrahim B. Salisu ◽  
Saira Azam ◽  
Mukhtar Ahmed ◽  
...  
Keyword(s):  
Plant Growth ◽  
Soil Bacteria ◽  
Biochemical Characterization ◽  
Experimental Studies ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bt Cotton ◽  
Bacterial Strains ◽  
Gm Plants ◽  
Bt Genes ◽  
Plant Growth Promoting

Genetically modified (GM) plants with insecticidal Bacillus thuringiensis (Bt) genes are widely accepted but their commercial utilization highlights the biosafety issues worldwide. The risk assessment of GM crops demonstrates their impact on the ecosystem as well as non-target organisms (NTOs). Among the NTOs, plant growth promoting rhizobacteria (PGPR) demand more critical experimental studies as they play a significant role in plant growth. A comparative study of Bt with non-Bt cotton rhizosphere was conducted, on selected bacterial strains. During the course of the study, biochemical characterization, auxin biosynthesis and molecular characterization was done to assess the effect of Bt toxins (Cry1Ac and Cry2A) on non-target PGPR strains. A significant decrease (p<0.05) in phosphatase activity was recorded in some of the experimental bacterial strains as compared to those of control strains. However, no significant differences (p>0.05) were observed in other parameters like bacterial population, colony morphologies as well as biochemical activities. Thus, our study demonstrates the safe plantation of Bt crops with respect to soil bacteria.

scholarly journals PGPR Characteristics of Rhizospheric Bacteria to Understand the Mechanisms of Faba Bean Growth

Proceedings ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 27
Author(s):  
Rim Tinhinen Maougal ◽  
Maya Kechid ◽  
Chaima Ladjabi ◽  
Abdelhamid Djekoun
Keyword(s):  
Plant Growth ◽  
Faba Bean ◽  
Biochemical Characterization ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Strains ◽  
Rhizospheric Bacteria ◽  
Plant Growth Promoting ◽  
Pgpr Traits ◽  
Taxonomic Groups ◽  
High Degree

Rhizobacteria play an important role in maintaining soil balance. Among these bacteria, there are those taht have shown their ability to promote the growth of plants, known as Plant Growth Promoting Rhizobacteria (PGPR). In our work, we are interested in characterizing 110 bacterial strains isolated in the field in the region of Ben Badis (Constantine Algeria) from 5 varieties of faba bean. Phenotypic and biochemical characterization showed that most of the isolates are cream-colored, slightly raised, flat and opaque, Gram−, catalase+ and oxidase−, and Bacillus form. PCA analysis allowed us to select 40 isolates with a high degree of variability to continue our work. The results obtained have directed us towards different taxonomic groups (rhizobium, Pseudomonas, Bacillus etc.). The evaluation of the PGPR potential of bacteria (phytostimulation, biofertilization and biocontrol), showed that 100% of bacteria are able to produce auxin at different concentrations, with the highest concentration (177.77 µg/mL) for the isolate 6, and that more than 50% of isolates are capable of producing nitrogen, ammonia and phytate mineralization. These PGPR traits have a direct effect on plant growth of five varieties of the faba bean and can be used to select the best performing bacteria for inoculation tests.

A novel procedure for rapid isolation of plant growth promoting pseudomonads

1995 ◽  
Vol 41 (6) ◽  
pp. 533-536 ◽  
Author(s):  
Bernard R. Glick ◽  
Damir M. Karaturovíc ◽  
Peter C. Newell
Keyword(s):  
Plant Growth ◽  
Soil Bacteria ◽  
Acc Deaminase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Bacterial Strains ◽  
Seedling Root ◽  
N Source ◽  
Plant Growth Promoting ◽  
Promote Plant Growth ◽  
Growth Promoting

A rapid and novel procedure for the isolation of plant growth promoting rhizobacteria (PGPR) is described. This method entails screening soil bacteria for the ability to utilize the compound 1-aminocyclopropane-1-carboxylate (ACC) as a sole N source, a trait that is a consequence of the presence of the activity of the enzyme ACC deaminase. This trait appears to be limited to soil bacteria that are also capable of stimulating plant growth. Seven different soil samples from two geographically disparate locations were found to contain pseudomonads that were able to to utilize ACC as a N source. Each of the seven strains was shown, by the ability of the bacterium to promote canola seedling root elongation under gnotobiotic conditions, to be a PGPR. The method described here may be used to replace the otherwise slow and tedious process of testing individual bacterial strains for their ability to promote plant growth, thereby significantly speeding up the process of finding new PGPR.Key words: plant growth promoting rhizobacteria, PGPR, 1-aminocyclopropane-1-carboxylate, ACC, ACC deaminase, bacterial fertilizer, soil bacteria.

scholarly journals Selection of Saccharum spp. rhizobacteria with growth-promoting properties using PCA analysis

2020 ◽  
pp. 1186-1194
Author(s):  
Roberta Mendes dos Santos ◽  
Everlon Cid Rigobelo
Keyword(s):  
Plant Growth ◽  
Principal Component ◽  
Plant Growth Promoting Rhizobacteria ◽  
Cellulolytic Activity ◽  
Bacterial Strains ◽  
Saccharum Spp ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Enterobacter Asburiae ◽  
Selection Of

The search for plant growth-promoting rhizobacteria is an ongoing need for the development of new bioinoculants for use in various crops, including sugarcane. Bacterial strains with various plant growth-promoting properties can contribute to sustainable agricultural production. The present study aimed to isolate, characterize and select sugarcane rhizobacteria from six different varieties through principal components analysis. This study selected 167 bacterial strains with the ability to fix nitrogen, produce indolacetic acid, exhibit cellulolytic activity, and solubilize phosphate and potassium were isolated. Of these 167 bacterial strains, seven were selected by principal component analysis and identified as belonging to the genera Staphylococcus, Enterobacter, Bacillus and Achromobacter. Bacillus thuringiensis IP21 presented higher potential for nitrogen fixation and CaPO4 and AlPO4 solubilization and a lower potential for K solubilization in sugarcane. Enterobacter asburiae IP24 was efficient in indolacetic acid production and CaPO4 and FePO4 solubilization and inefficient for Araxá apatite solubilization.

scholarly journals A Critical Review on Plant Growth-Promoting Rhizobacteria (PGPR) as a Drought Stress Management Tool

2021 ◽  
pp. 44-66
Author(s):  
Shamal S. Kumar ◽  
Ananta G. Mahale ◽  
Md. Mifta Faizullah ◽  
J. Radha Krishna ◽  
Tharun K. Channa
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Plant Root ◽  
Acc Deaminase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Management Tool ◽  
Abiotic Factor ◽  
Bacterial Strains ◽  
Plant Growth Promoting ◽  
Growth Promoting

Water scarcity is known as a major stumbling block towards crop development and its output all over the world. Certain free-living bacterial strains have been found near the plant root zones which have shown to improve resistance of plants towards water stress. Despite availability of basic nutrients, drought an abiotic factor substantially inhibits growth, development and yield of crops by causing an increase in ethylene levels. It is a good idea to incorporate the use of a management tool which is the utilization of plant growth-promoting rhizobacteria to help several crops manage drought conditions. Drought stress in crops can be alleviated by reducing ethylene synthesis, exopolysaccharide, osmoregulation, Indole-3-acetic acid and aggregation with the ACC deaminase-containing plant growth-promoting rhizobacteria. Inoculating pathogens like root rot (Macrophomina phaseolina) affected plant with Pseudomonas fluorescens strain TDK1 with ACC deaminase function improves drought stress. Using plant growth-promoting rhizobacteria to mitigate the negative imbibes of drought in most crops is a good idea. Several studies have been carried out on plant growth-promoting rhizobacteria, as its inoculation not only manages drought related conditions but increases root hair growth and lateral root, which assist in increased water and nutrient uptake. It limits ethylene supply, alternatively increases plant root growth by hydrolyzing 1-aminocyclopropane-1-carboxylic acid (ACC). This review will give us a perspective on the importance of plant growth-promoting rhizobacteria, as it is one of the efficient tools that helps manage drought stress on several crops.

scholarly journals Microbial IAA: Spectral Analysis and Application to Modulate Growth of Triticum aestivum

2018 ◽  
Vol 9 (2) ◽  
pp. 53-63
Author(s):  
Ammara Abid ◽  
Ambreen Ahmed
Keyword(s):  
Triticum Aestivum ◽  
Spectral Analysis ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Structural Similarity ◽  
Bacterial Strains ◽  
Plant Microbe Interaction ◽  
Plant Growth Promoting ◽  
Microbial Strains ◽  
Growth Promoting

Plant growth promoting rhizobacteria (PGPR) play an essential part in transformation, solubilization, and mobilization of nutrients procured from the soil. Plant-microbe interaction can be termed as an eco-friendly approach which not only improves plant growth but helps in sustaining the soil and prevents environmental degradation from agrochemicals. PGPR improve plant growth through various mechanisms. One of the mechanisms involved is phytohormone production by the bacterial strains. In the current study, spectral analysis of thirteen already isolated and identified auxin-producing microbial strains (AAL1, AB8, A7B, A5C, A3E, A11E, AL2, A9G, A12G, A13G, AM10, P4, and S6) was carried out. Fourier transform infrared spectroscopy (FTIR) of the bacterial IAA exhibited close structural similarity between bacterial IAA and standard IAA. The growth-enhancing capability of strains was verified through the application of these strains on Triticum aestivum seedlings and enhancement of growth was statistically analyzed which indicated remarkable improvement in growth and metabolism both under laboratory and field conditions. Several bacterial isolates also proved to be very effective in improving biochemical parameters of plants. The current study suggested that the application of IAA-producing PGPR as biofertilizer is effective in enhancing plant growth as well as plant yield.

scholarly journals Evidence for Induced Systemic Protection to Fusiform Rust in Loblolly Pine by Plant Growth-Promoting Rhizobacteria

Plant Disease ◽  
2000 ◽  
Vol 84 (3) ◽  
pp. 306-308 ◽  
Author(s):  
S. A. Enebak ◽  
W. A. Carey
Keyword(s):  
Plant Growth ◽  
Loblolly Pine ◽  
Bacillus Pumilus ◽  
Plant Growth Promoting Rhizobacteria ◽  
Systemic Resistance ◽  
Bacterial Strains ◽  
Fusiform Rust ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Combined Data

Trials conducted in 1997 and 1998 tested eight strains of plant growth-promoting rhizobacteria (PGPR) for their capacity to induce systemic protection in loblolly pine to the causal agent of fusiform rust. Pine seeds were treated with bacteria at time of sowing, and seedlings were artificially inoculated with basidiospores of Cronartium quercuum f. sp. fusiforme 1 month later. Six months after basidiospore inoculation, seedlings were evaluated for the fusoid swelling or galls characteristic of rust infection. Compared with seedlings from seed not treated with bacteria, two bacterial isolates, Bacillus pumilus (SE34) and Serratia marcescens (90–166), significantly (P = 0.05) reduced the number of galls in 1997 and 1998. Combined data from 1997 and 1998 resulted in two additional isolates, B. pumilus (INR7) and B. pumilus (SE52), significantly (P = 0.05) reducing the number of galls. Averaged over both years, 31% of control seedlings were infected with fusiform rust, while those seedlings treated with bacterial strains SE34, 90–166, INR7, and SE52 had 13, 14, 15, and 16% infection, respectively. These four PGPR strains appear to have induced systemic resistance to fusiform rust in loblolly pine, resulting in less infection over nontreated control seedlings.

Characterization of plant growth promoting rhizobacteria isolated from polluted soils and containing 1-aminocyclopropane-1-carboxylate deaminase

2001 ◽  
Vol 47 (7) ◽  
pp. 642-652 ◽  
Author(s):  
Andrei A Belimov ◽  
Vera I Safronova ◽  
Tatyana A Sergeyeva ◽  
Tatyana N Egorova ◽  
Victoria A Matveyeva ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Elongation ◽  
Indian Mustard ◽  
Acc Deaminase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Sand Culture ◽  
Bacterial Strains ◽  
Pot Experiments ◽  
Plant Growth Promoting ◽  
Growth Promoting

Fifteen bacterial strains containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase were isolated from the rhizoplane of pea (Pisum sativum L.) and Indian mustard (Brassica juncea L.) grown in different soils and a long-standing sewage sludge contaminated with heavy metals. The isolated strains were characterized and assigned to various genera and species, such as Pseudomonas brassicacearum, Pseudomonas marginalis, Pseudomonas oryzihabitans, Pseudomonas putida, Pseudomonas sp., Alcaligenes xylosoxidans, Alcaligenes sp., Variovorax paradoxus, Bacillus pumilus, and Rhodococcus sp. by determination of 16S rRNA gene sequences. The root elongation of Indian mustard and rape (Brassica napus var. oleifera L.) germinating seedlings was stimulated by inoculation with 8 and 13 isolated strains, respectively. The bacteria were tolerant to cadmium toxicity and stimulated root elongation of rape seedlings in the presence of 300 µM CdCl2 in the nutrient solution. The effect of ACC-utilising bacteria on root elongation correlated with the impact of aminoethoxyvinylglycine and silver ions, chemical inhibitors of ethylene biosynthesis. A significant improvement in the growth of rape caused by inoculation with certain selected strains was also observed in pot experiments, when the plants were cultivated in cadmium-supplemented soil. The biomass of pea cv. Sparkle and its ethylene sensitive mutant E2 (sym5), in particular, was increased through inoculation with certain strains of ACC-utilising bacteria in pot experiments in quartz sand culture. The beneficial effect of the bacteria on plant growth varied significantly depending on individual bacterial strains, plant genotype, and growth conditions. The results suggest that plant growth promoting rhizobacteria containing ACC deaminase are present in various soils and offer promise as a bacterial inoculum for improvement of plant growth, particularly under unfavourable environmental conditions.Key words: ACC deaminase, cadmium, ethylene, Indian mustard, pea, phytoremediation, rape, rhizobacteria.

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