Influence Of Plant Growth Promoting Rhizobacteria Research Articles

Influence of Plant Growth-Promoting Rhizobacteria on the Formation of Apoplastic Barriers and Uptake of Water and Potassium by Wheat Plants.

The formation of apoplastic barriers is important for controlling the uptake of water and ions by plants, thereby influencing plant growth. However, the effects of plant growth-promoting bacteria on the formation of apoplastic barriers, and the relationship between these effects and the ability of bacteria to influence the content of hormones in plants, have not been sufficiently studied. The content of cytokinins, auxins and potassium, characteristics of water relations, deposition of lignin and suberin and the formation of Casparian bands in the root endodermis of durum wheat (Triticum durum Desf.) plants were evaluated after the introduction of the cytokinin-producing bacterium Bacillus subtilis IB-22 or the auxin-producing bacterium Pseudomonas mandelii IB-Ki14 into their rhizosphere. The experiments were carried out in laboratory conditions in pots with agrochernozem at an optimal level of illumination and watering. Both strains increased shoot biomass, leaf area and chlorophyll content in leaves. Bacteria enhanced the formation of apoplastic barriers, which were most pronounced when plants were treated with P. mandelii IB-Ki14. At the same time, P. mandelii IB-Ki14 caused no decrease in the hydraulic conductivity, while inoculation with B. subtilis IB-22, increased hydraulic conductivity. Cell wall lignification reduced the potassium content in the roots, but did not affect its content in the shoots of plants inoculated with P. mandelii IB-Ki14. Inoculation with B. subtilis IB-22 did not change the potassium content in the roots, but increased it in the shoots.

The influence of plant growth-promoting rhizobacteria (PGPR) on the cultivation of Cynara Scolymus L. under salinity stress

This article highlights laboratory and field experiments based on the results of treatment of Cynara scolymus L. with biologically active products. According to the obtained results, compared to the control variant in the field experiments, the highest result was 3.4% to 4.8% in 1:100 and 1:1000 ratios of “Elisitor”. Similar results were observed to increase 0.3%, 3.0% respectively in 1:1000 and 1:100 ratios of “Zamin-M” biopreparation. According to the analyzes carried out in laboratory conditions, the fertility indicator was found to be 95.0% in plants treated with the biopreparation “Elicitor”. This result was 6.0% higher than the control and 3.4% higher than the standard. Fertilization in plants inoculated with “Zamin-M” biopreparation was found to be 93.85%, it was increased by 4.85% compared to the control variant and by 2.25% compared to standard variant.

Influence of Plant Growth-Promoting Rhizobacteria and vermicompost tea on a pomegranate tree

Influence of Plant Growth-Promoting Rhizobacteria and vermicompost tea on a pomegranate tree

Influence of PGPR, Bio-Phosphate Microorganism and Phosphate on Growth of Oil Palm Seedlings Under Drought Stress Conditions

Drought is a major abiotic stress that threatens the production of agricultural oil palms. Drought interferes with plant uptake of phosphorus. The goal of this study was to investigate how plant growth-promoting rhizobacteria (PGPR), bio-phosphate microorganisms, and phosphate affected oil palm growth under drought stress. The study was conducted at the Tri Dharma Research Station INSTIPER in Yogyakarta from January to May 2020, and it used a factorial and completely randomized design with two factors and three replicates per treatment. The first factor was a fertilization treatment that included P1 (PGPR), P2 (bio-phosphate microorganisms), P3 (phosphate). The second factor was a drinking interval of L1 (once per day) and L2 (once per seven days). At 120 days after planting, data were collected. The results showed that the PGPR, bio-phosphate microorganisms and phosphate had no significant effect on plant height, number of leaves, leaf area, chlorophyll content, dry weight of plants, volume of root, dry weight of root and shoot, stem diameter, number of stomata, and root-shoot ratio. Root volume, root dry weight, and root-shoot ratio were significantly affected by one-day and seven-day watering intervals. Phosphate fertilization with watering once every seven days considerably increased the width of the stomata openingsI
 Keywords: PGPR, Bio-Phosphate, Phosphate, Oil Palm, Drought

Influence of Plant Growth-Promoting Rhizobacteria on Corn Growth under Drought Stress

ABSTRACTWater availability is a major constraint affecting the growth and yield of crops/plants worldwide. Some studies have shown that specific strains of free-living bacteria found in the plant rhizosphere can improve the tolerance of plants during water stress. A greenhouse study was conducted to evaluate the effects of two mixtures of plant growth-promoting rhizobacteria (PGPR) and two fertilizer sources on root establishment and biomass production of corn (Zea mays L.) during the early growth stages under drought conditions. This study was conducted as a randomized complete block design with five replications. Treatments included three irrigation levels (watering every 3, 6, and 12 days), two fertilizer materials (poultry litter and urea), and two PGPR strain mixtures and a non-inoculated control. Irrigation significantly affected plant growth and biomass accumulation of corn at the V6 to VT stages. Compared to poultry litter, urea application significantly increased plant height, leaf chlorophyll (SPAD readings), leaf area, and plant biomass. PGPR significantly improved plant height, stem diameter, leaf chlorophyll, and root morphology under drought stress conditions. The results demonstrate that PGPR inoculation can stimulate enhanced plant root development (through the production of plant growth regulators), thereby resulting in better absorption of water and nutrients from the soil.

Influence of Plant Growth-Promoting Rhizobacteria on Corn Growth Under Different Fertility Sources

ABSTRACTA greenhouse study was conducted to evaluate the effects of plant growth-promoting rhizobacteria (PGPR) on root establishment and biomass production of corn (Zea mays L.) using three fertility sources (poultry litter (PL), biosolids, and urea). Applying PL significantly improved root morphological parameters and increased plant biomass at the V4, V6, and VT growth stages when compared to the other fertility sources. At the V4 stage, PGPR stimulated root growth and enhanced aboveground biomass with urea and PL, while no differences were observed with biosolids. At the V6 stage, PL, biosolids, and urea with PGPR significantly increased some growth parameters (e.g., plant height, leaf area, and root morphology). However, at the VT stage, PGPR’s influence on plant growth was minimal regardless of fertility source. Applying the fertility sources at 135 kg N ha−1 may have masked PGPR’s influence on corn growth as the plants reached their later vegetative growth stages.

Influence of plant growth-promoting rhizobacteria (PGPR) on blackberry (Rubus glaucus Benth. cv. thornless) growth under semi-cover and field conditions

Este estudio muestra el efecto de tres cepas de rizobacterias promotoras del crecimiento vegetal (PGPR) del género Bacillus sobre el desarrollo de la mora (Rubus glaucus Benth) bajo condiciones de semitecho y libre exposición (sistemas de cultivo). La cepa endógena Bacillus subtilis GIBI-200, B. pumilus GIBI-206, su mezcla (B. subtilis GIBI-200 + B. pumilus GIBI-206) y la cepa comercial B. subtilis QTS-713 se compararon con la fertilización mineral convencional (Control) en cada sistema de cultivo. El sistema a libre exposición presentó valores más altos (P <0.001) que el semitecho en: número total de ramas (7.32), número de ramas productivas (7.0), flores por racimo (26.2) y menor porcentaje de ramas improductivas (6.1%). Se obtuvo diferencias significativas (P <0.05) en el número total de ramas a través del tiempo como efecto las cepas bacterianas. No obstante, la última observación de esta variable no presentó diferencias estadísticas entre cepas y fertilización mineral. No se observaron diferencias significativas en términos de número, longitud, diámetro y flores en las ramas productivas como efecto de las cepas bacterianas y el Control. B. subtilis GIBI-200 + B. pumilus GIBI-206 mostró un comportamiento estadístico similar comparado con la fertilización mineral en el número de racimos (8.3) y porcentaje de ramas improductivas (11.1%). Además, GIBI-200 + GIBI-206, a pesar de la igualdad estadística, expuso mayores valores que las cepas individuales. El sistema a libre exposición sigue siendo la alternativa más prometedora para el desarrollo de cultivos de mora y PGPR actúan como biofertilizantes permitiendo lograr efectos en el crecimiento a largo plazo de mora similar a la fertilización mineral. Las mezclas de PGPR pueden producir un efecto sinérgico y nuevas combinaciones deben ser evaluadas en futuros estudios.

Influence of PGPR and AMF on antioxidant activity, lycopene and potassium contents in tomato

In this study, the impact of inoculating tomato (Lycopersicon esculentum F1Hybrid, GS -15) roots with plant growth-promoting rhizobacteria (PGPR) andarbuscular mycorrhiza fungi (AMF) on fruit quality was evaluated. The control treatment was non-inoculated, the PGPR treatments were inoculated withPseudomonas putida, Azotobacter chroococcum and Azosprillum lipoferum,and the AMF treatment was inoculated with mixture of Glomus intaradics + Glomus mossea + Glomus etunicatum. Compared to the control treatment, phytochemical factors, containing lycopene and antioxidant activity, shoot and fruit potassium increased by PGPR and AMF treatments. Maximum lycopene and antioxidant activity were found in plants of the Pseudomonas + Azotobacter + Azosprillum + AMF treatment. A positive correlation between lycopene with shoot potassium (r = 0.89, p<0.01) and fruit potassium (r = 0.86, p<0.01) was found. Minimum antioxidant activity was observed in plants of the Pseudomonas + Azotobacter treatment, but when AMF were added to this treatment, antioxidant activity increased significantly. In all treatments, shoot and fruit potassium increased when PGPR and AMF were used together. It was found that the application of Pseudomonas + Azotobacter + Azosprillum + AMF treatment had the most effect on lycopene, antioxidant activity and potassium contents on tomato. Key words: Fruit quality, mycorrhiza, rhizobacteria, tomato.

Comparison of sole carbon source profiles monitored at two different wavelengths

Profiles of sole carbon source utilization are increasingly used to characterize microbial communities in various environments. Metabolization of a single carbon source is detected by monitoring a colorimetric reaction. In most work, either of two different wavelengths, 405 or 590 nm, has been employed for detection. In the present study we compared the outcome of these two detection modes applied to a study of the influence of plant growth-promoting rhizobacteria on the root-inhabiting microbial communities on the roots of young tomato plants. The results showed different average well color development and number of positive wells when detected at the two wavelengths with respect to the development of the single curve, absolute values and standard deviation. Further, the carbon source that was utilized the most by the rhizosphere microflora was not congruent between the two reading modes. The overall results, however, were similar, as evaluated by multivariate statistics. In conclusion, this study indicates that the carbon source utilization profiles should be standardized with respect to the wavelength used to enable comparability or development of models on the microbial status in ecosystems.