scholarly journals Screening of plant growth promoting bacteria associated with barley plants (Hordeum vulgare L.) cultivated in South Brazil

2015 ◽  
Vol 15 (2) ◽  
Author(s):  
Andress P. Pontes ◽  
Rocheli de Souza ◽  
Camille E. Granada ◽  
Luciane M.P. Passaglia

The occurrence of associations between bacteria and plant roots may be beneficial, neutral or detrimental. Plant growth promoting (PGP) bacteria form a heterogeneous group of beneficial microorganisms that can be found in the rhizosphere, the root surfaces or in association with host plant. The aim of this study was to isolate and characterize PGP bacteria associated to barley plants (Hordeum vulgare L.) aiming a future application as agricultural inoculant. One hundred and sixty bacterial strains were isolated from roots or rhizospheric soil of barley based on their growth in nitrogen-free selective media. They were evaluated for their ability to produce indolic compounds (ICs) and siderophores, and to solubilize tricalcium phosphate inin vitro assays. Most of them (74%) were able to synthesize ICs in the presence of the precursor L-tryptophan, while 57% of the isolates produced siderophores in Fe-limited liquid medium, and 17% were able to solubilize tricalcium phosphate. Thirty-two isolates possessing different PGP characteristics were identified by partial sequencing of their 16S rRNA gene. Strains belonging to Cedecea andMicrobacterium genera promoted the growth of barley plants in insoluble phosphate conditions, indicating that these bacteria could be used as bioinoculants contributing to decrease the amount of fertilizers applied in barley crops.

2021 ◽  
Vol 8 (sp1) ◽  
pp. 17-24
Author(s):  
Tanvir Kaur ◽  
Rubee Devi ◽  
Divjot Kour ◽  
Ashok Yadav ◽  
Ajar Nath Yadav

Potassium (K) is the foremost macronutrients for growth of plant, soil health and fertility. The huge application of NPK chemical fertilizers negatively impacts the economy and is a threat to environmental sustainability. The rapid depletion of K mineral in soil is due to the application of agrochemicals agricultural fields for the production of crops in India. In present investigation, K-solubilizing microbes (KSM) were isolated and enumerated from cereal crops growing in Sirmour Himachal Pradesh. A total 125 bacteria were isolated and screened for K- solubilization on Aleksandrov agar plates and found that 31 bacterial strains exhibited K-solubilization. These 31 K-solubilizing strains of bacteria were additionally screened for other plant growth promoting (PGP) potential including solubilization of minerals, production of siderophores, ammonia, hydrogen cyanide and indole acetic acids. The performance of an efficient K-solubilizer was evaluated for plant growth promoting ability in pot assay under in vitro conditions. The strain EU-LWNA-25 positively influenced shoot length, fresh weight, carotenoids and total sugar content than the full dose, half dose and control. The strain enhancing physiological and growth parameters was identified by BLASTn analysis as Pseudomonas gessardii EU-LWNA-25. K-solubilizing plant growth promoting bacteria could be suitable bioinoculants for Rabi seasonal crops and overcomes the challenges of sustainable agriculture in K-deficient soil.


2017 ◽  
Vol 71 (3) ◽  
pp. 195-200 ◽  
Author(s):  
Snezana Djordjevic ◽  
Dragana Stanojevic ◽  
Milka Vidovic ◽  
Violeta Mandic ◽  
Ivana Trajkovic

The standard technology of seed processing uses mainly chemical products. Recent researches showed that toxic materials from chemical fertilizers can be harmful to humans, animals and the environment. Currently the attention of researches is shifting away from chemical fertlizers and toward alternative that consumers perceive to be natural, Plant Growth Promoting bacteria (PGP). PGP bacteria could be a way to reduce chemical fertilizer doses. This was the reason to test the ability of Bacillus megaterium, Azotobacter chroococcum to produce hormone auxin (IAA). Bacterial strains were identified by PCR amplification and sequencing of the 16S rRNA gene. Indole-3-acetic acid (IAA) was detected and quantified by MRM experiment. This study conducted that maize seed inoculation with IAA from species mentioned above showed positive effects. They had statistically significantly higher root and steam height compared to control seedlings. Bacterial strains tested in this study may be recommended as PGP (Plant Growth Promoting) bacteria, due to their positive effects and eventually can be used to reduce chemical fertilizers doses.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 912
Author(s):  
Shuming Liu ◽  
Hongmei Liu ◽  
Rui Chen ◽  
Yong Ma ◽  
Bo Yang ◽  
...  

Miscanthus spp. are energy plants and excellent candidates for phytoremediation approaches of metal(loid)s-contaminated soils, especially when combined with plant growth-promoting bacteria. Forty-one bacterial strains were isolated from the rhizosphere soils and roots tissue of five dominant plants (Artemisia argyi Levl., Gladiolus gandavensis Vaniot Houtt, Boehmeria nivea L., Veronica didyma Tenore, and Miscanthus floridulus Lab.) colonizing a cadmium (Cd)-contaminated mining area (Huayuan, Hunan, China). We subsequently tested their plant growth-promoting (PGP) traits (e.g., production of indole-3-acetic acid, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase) and Cd tolerance. Among bacteria, two strains, Klebsiella michiganensis TS8 and Lelliottia jeotgali MR2, presented higher Cd tolerance and showed the best results regarding in vitro growth-promoting traits. In the subsequent pot experiments using soil spiked with 10 mg Cd·kg−1, we investigated the effects of TS8 and MR2 strains on soil Cd phytoremediation when combined with M. floridulus (Lab.). After sixty days of planting M. floridulus (Lab.), we found that TS8 increased plant height by 39.9%, dry weight of leaves by 99.1%, and the total Cd in the rhizosphere soil was reduced by 49.2%. Although MR2 had no significant effects on the efficiency of phytoremediation, it significantly enhanced the Cd translocation from the root to the aboveground tissues (translocation factor > 1). The combination of K. michiganensis TS8 and M. floridulus (Lab.) may be an effective method to remediate Cd-contaminated soils, while the inoculation of L. jeotgali MR2 may be used to enhance the phytoextraction potential of M. floridulus.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.


Soil Systems ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 10
Author(s):  
Anithadevi Kenday Sivaram ◽  
Logeshwaran Panneerselvan ◽  
Kannappar Mukunthan ◽  
Mallavarapu Megharaj

Pyroligneous acid (PA) is often used in agriculture as a plant growth and yield enhancer. However, the influence of PA application on soil microorganisms is not often studied. Therefore, in this study, we investigated the effect of PA (0.01–5% w/w in soil) on the microbial diversity in two different soils. At the end of eight weeks of incubation, soil microbial community dynamics were determined by Illumina-MiSeq sequencing of 16S rRNA gene amplicons. The microbial composition differed between the lower (0.01% and 0.1%) and the higher (1% and 5%) concentration in both PA spiked soils. The lower concentration of PA resulted in higher microbial diversity and dehydrogenase activity (DHA) compared to the un-spiked control and the soil spiked with high PA concentrations. Interestingly, PA-induced plant growth-promoting bacterial (PGPB) genera include Bradyrhizobium, Azospirillum, Pseudomonas, Mesorhizobium, Rhizobium, Herbaspiriluum, Acetobacter, Beijerinckia, and Nitrosomonas at lower concentrations. Additionally, the PICRUSt functional analysis revealed the predominance of metabolism as the functional module’s primary component in both soils spiked with 0.01% and 0.1% PA. Overall, the results elucidated that PA application in soil at lower concentrations promoted soil DHA and microbial enrichment, particularly the PGPB genera, and thus have great implications for improving soil health.


2021 ◽  
Vol 12 ◽  
Author(s):  
Faten Ghodhbane-Gtari ◽  
Timothy D’Angelo ◽  
Abdellatif Gueddou ◽  
Sabrine Ghazouani ◽  
Maher Gtari ◽  
...  

Actinorhizal plants host mutualistic symbionts of the nitrogen-fixing actinobacterial genus Frankia within nodule structures formed on their roots. Several plant-growth-promoting bacteria have also been isolated from actinorhizal root nodules, but little is known about them. We were interested investigating the in planta microbial community composition of actinorhizal root nodules using culture-independent techniques. To address this knowledge gap, 16S rRNA gene amplicon and shotgun metagenomic sequencing was performed on DNA from the nodules of Casuarina glauca. DNA was extracted from C. glauca nodules collected in three different sampling sites in Tunisia, along a gradient of aridity ranging from humid to arid. Sequencing libraries were prepared using Illumina NextEra technology and the Illumina HiSeq 2500 platform. Genome bins extracted from the metagenome were taxonomically and functionally profiled. Community structure based off preliminary 16S rRNA gene amplicon data was analyzed via the QIIME pipeline. Reconstructed genomes were comprised of members of Frankia, Micromonospora, Bacillus, Paenibacillus, Phyllobacterium, and Afipia. Frankia dominated the nodule community at the humid sampling site, while the absolute and relative prevalence of Frankia decreased at the semi-arid and arid sampling locations. Actinorhizal plants harbor similar non-Frankia plant-growth-promoting-bacteria as legumes and other plants. The data suggests that the prevalence of Frankia in the nodule community is influenced by environmental factors, with being less abundant under more arid environments.


2010 ◽  
Vol 56 (No. 12) ◽  
pp. 570-573 ◽  
Author(s):  
D. Egamberdieva

In this study the plant growth-promoting bacteria were analysed for their growth-stimulating effects on two wheat cultivars. The investigations were carried out in pot experiments using calcareous soil. The results showed that bacterial strains Pseudomonas spp. NUU1 and P. fluorescens NUU2 were able to colonize the rhizosphere of both wheat cultivars. Their plant growth-stimulating abilities were affected by wheat cultivars. The bacterial strains Pseudomonas sp. NUU1 and P. fluorescens NUU2 significantly stimulated the shoot and root length and dry weight of wheat cv. Turon, whereas cv. Residence was less affected by bacterial inoculation. The results of our study suggest that inoculation of wheat with Pseudomonas strains can improve plant growth in calcareous soil and it depends upon wheat cultivars. Prior to a selection of good bacterial inoculants, it is recommended to select cultivars that benefit from association with these bacteria.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6076 ◽  
Author(s):  
Hadia -e- Fatima ◽  
Ambreen Ahmed

Bacteria are tiny organisms which are ubiquitously found in the environment. These microscopic living bodies are responsible for the flow of nutrients in biogeochemical cycles and fertility imparted to the soil. Release of excessive chromium in agricultural soils due to rapid growth of industries may result in minimizing the fertility of soil in future, which will lead to reduction in crop production. Plant growth promoting bacteria (PGPB) are beneficial to the environment, some of which can tolerate chromium and protect plants against heavy metal stress. The current study aims to identify such chromium-tolerant auxin-producing rhizobacteria and to investigate their inoculation effects on the growth characteristics of Lens culinaris in chromium polluted soils by using two different chromium salts i.e., K2Cr2O7 and K2CrO4 in varying concentrations (0, 50, 100, 200, 400 and 500 µgml−1). The results revealed that Bacillus species are efficient in significantly reducing the deleterious effects of Cr. These effective bacterial strains were able to stimulate the growth of metal effected plants of Lens culinaris which were grown in chromium contaminated environment. Therefore, these plant growth promoting rhizobacteria PGPRs, having both auxin production potential and chromium-resistance ability, are considered as efficient micro-factories against chromium pollution.


Author(s):  
CLARA IVETTE RINCON-MOLINA ◽  
FRANCISCO ALEXANDER RINCON-MOLINA ◽  
ADALBERTO ZENTENO-ROJAS ◽  
VICTOR MANUEL RUIZ-VALDIVIEZO ◽  
JOSE MIGUEL CULEBRO-RICALDI ◽  
...  

ABSTRACT Objective: Study the diversity of cultivable rhizospheric bacteria associated to Agave americana, and select native strains with potential as plant growth-promoting bacteria (PGPB). Design/methodology/approach: The isolated bacteria were phenotypically characterized. The genetic diversity and identity of the strains were revealed by genomic fingerprints and by sequencing of 16S rRNA gene. Plant growth promoting ability and plant inoculation assays were evaluated to know the potential as PGPB. Results: A total of 235 strains were isolated from A. americana rhizosphere and were classified within of 10 different bacterial genera. Rhizobium, Pseudomonas, Acinetobacter had high potential as PGPB. Study limitations/implications Cultivable approach was used to study rhizobacteria. A metagenomic study could expand the knowledge about the structure and diversity of bacterial community associated to A. americana. Findings/conclusions Rhizosphere bacteria have potential use as biofertilizer for the cultivation and propagation of A. americana and other agave species.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Enriqueta Amora-Lazcano ◽  
Héctor J. Quiroz-González ◽  
Cristofer I. Osornio-Ortega ◽  
Juan A. Cruz-Maya ◽  
Janet Jan-Roblero

Background: Deficiency in sorghum growth in ecosystems of low-nutrient soils has been scarcely studied. This soil deficiency can be overcome by the addition of plant growth-promoting bacteria which increase sorghum growth. Questions and/or Hypotheses: indole acetic acid (IAA) producing and phosphate solubilizing bacteria can promote sorghum growth under nutritional stress. Studied species: Sorghum bicolor (L.) Moench. Study site and dates: Mexico City, 2018. Methods: Of the twelve bacterial strains utilized, three produce IAA (group BI), two strains produce IAA and siderophores (BIS group), four strains produce IAA and solubilize phosphate (BIP group), and three strains produce IAA, solubilize phosphate, and produce siderophores (BIPS group). Hydroponic bioassays and low-nutrient soil bioassay were used. Results: In hydroponic bioassays, for BI and BIS groups, five strains significantly increased the growth parameters with respect to the control, and for the BIP and BIPS groups, two strains promoted stem development and shoot dry weight. In a low-nutrient soil bioassay, Pseudomonas sp. BI-1 (from BI group) was the one that presented the highest percentages 32, 48, 140 and 79 % in stem diameter, height and dry weight of the shoot and dry weight of the root, respectively, followed by the P. mohnii BIPS-10 strain (from BIPS group) that exhibited similar results. Conclusions: IAA producing Pseudomonas strains improve the sorghum growth in a low-nutrient soil and suggest thatPseudomonas sp. BI-1 and P. mohnii BIPS-10 could be used as potential bioinoculants for sorghum.


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