scholarly journals Alone Yet Not Alone: Frankia Lives Under the Same Roof With Other Bacteria in Actinorhizal Nodules

2021 ◽  
Vol 12 ◽  
Author(s):  
Faten Ghodhbane-Gtari ◽  
Timothy D’Angelo ◽  
Abdellatif Gueddou ◽  
Sabrine Ghazouani ◽  
Maher Gtari ◽  
...  
Keyword(s):  
16S Rrna ◽  
Plant Growth ◽  
16S Rrna Gene ◽  
Root Nodules ◽  
Actinorhizal Plants ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Metagenomic Sequencing ◽  
Plant Growth Promoting ◽  
Growth Promoting

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.

scholarly journals Inorganic Chemical Fertilizer Application to Wheat Reduces the Abundance of Putative Plant Growth-Promoting Rhizobacteria

2021 ◽  
Vol 12 ◽  
Author(s):  
Tessa E. Reid ◽  
Vanessa N. Kavamura ◽  
Maïder Abadie ◽  
Adriana Torres-Ballesteros ◽  
Mark Pawlett ◽  
...  
Keyword(s):  
16S Rrna ◽  
Plant Growth ◽  
16S Rrna Gene ◽  
Fertilizer Application ◽  
Chemical Fertilizer ◽  
Rrna Gene ◽  
Plant Growth Promoting ◽  
Total Community ◽  
Inorganic Chemical ◽  
Growth Promoting

The profound negative effect of inorganic chemical fertilizer application on rhizobacterial diversity has been well documented using 16S rRNA gene amplicon sequencing and predictive metagenomics. We aimed to measure the function and relative abundance of readily culturable putative plant growth-promoting rhizobacterial (PGPR) isolates from wheat root soil samples under contrasting inorganic fertilization regimes. We hypothesized that putative PGPR abundance will be reduced in fertilized relative to unfertilized samples. Triticum aestivum cv. Cadenza seeds were sown in a nutrient depleted agricultural soil in pots treated with and without Osmocote® fertilizer containing nitrogen-phosphorous-potassium (NPK). Rhizosphere and rhizoplane samples were collected at flowering stage (10 weeks) and analyzed by culture-independent (CI) amplicon sequence variant (ASV) analysis of rhizobacterial DNA as well as culture-dependent (CD) techniques. Rhizosphere and rhizoplane derived microbiota culture collections were tested for plant growth-promoting traits using functional bioassays. In general, fertilizer addition decreased the proportion of nutrient-solubilizing bacteria (nitrate, phosphate, potassium, iron, and zinc) isolated from rhizocompartments in wheat whereas salt tolerant bacteria were not affected. A “PGPR” database was created from isolate 16S rRNA gene sequences against which total amplified 16S rRNA soil DNA was searched, identifying 1.52% of total community ASVs as culturable PGPR isolates. Bioassays identified a higher proportion of PGPR in non-fertilized samples [rhizosphere (49%) and rhizoplane (91%)] compared to fertilized samples [rhizosphere (21%) and rhizoplane (19%)] which constituted approximately 1.95 and 1.25% in non-fertilized and fertilized total community DNA, respectively. The analyses of 16S rRNA genes and deduced functional profiles provide an in-depth understanding of the responses of bacterial communities to fertilizer; our study suggests that rhizobacteria that potentially benefit plants by mobilizing insoluble nutrients in soil are reduced by chemical fertilizer addition. This knowledge will benefit the development of more targeted biofertilization strategies.

scholarly journals Mining the Microbiome of Key Species from African Savanna Woodlands: Potential for Soil Health Improvement and Plant Growth Promotion

2020 ◽  
Vol 8 (9) ◽  
pp. 1291
Author(s):  
Ivete Sandra Maquia ◽  
Paula Fareleira ◽  
Isabel Videira e Castro ◽  
Denise R. A. Brito ◽  
Ricardo Soares ◽  
...  
Keyword(s):  
16S Rrna ◽  
Plant Growth ◽  
16S Rrna Gene ◽  
Bacterial Communities ◽  
Fire Regimes ◽  
Rrna Gene ◽  
Wide Range ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Culture Dependent

(1) Aims: Assessing bacterial diversity and plant-growth-promoting functions in the rhizosphere of the native African trees Colophospermum mopane and Combretum apiculatum in three landscapes of the Limpopo National Park (Mozambique), subjected to two fire regimes. (2) Methods: Bacterial communities were identified through Illumina Miseq sequencing of the 16S rRNA gene amplicons, followed by culture dependent methods to isolate plant growth-promoting bacteria (PGPB). Plant growth-promoting traits of the cultivable bacterial fraction were further analyzed. To screen for the presence of nitrogen-fixing bacteria, the promiscuous tropical legume Vigna unguiculata was used as a trap host. The taxonomy of all purified isolates was genetically verified by 16S rRNA gene Sanger sequencing. (3) Results: Bacterial community results indicated that fire did not drive major changes in bacterial abundance. However, culture-dependent methods allowed the differentiation of bacterial communities between the sampled sites, which were particularly enriched in Proteobacteria with a wide range of plant-beneficial traits, such as plant protection, plant nutrition, and plant growth. Bradyrhizobium was the most frequent symbiotic bacteria trapped in cowpea nodules coexisting with other endophytic bacteria. (4) Conclusion: Although the global analysis did not show significant differences between landscapes or sites with different fire regimes, probably due to the fast recovery of bacterial communities, the isolation of PGPB suggests that the rhizosphere bacteria are driven by the plant species, soil type, and fire regime, and are potentially associated with a wide range of agricultural, environmental, and industrial applications. Thus, the rhizosphere of African savannah ecosystems seems to be an untapped source of bacterial species and strains that should be further exploited for bio-based solutions.

scholarly journals Effect of Pyroligneous Acid on the Microbial Community Composition and Plant Growth-Promoting Bacteria (PGPB) in Soils

Soil Systems ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 10
Author(s):  
Anithadevi Kenday Sivaram ◽  
Logeshwaran Panneerselvan ◽  
Kannappar Mukunthan ◽  
Mallavarapu Megharaj
Keyword(s):  
Microbial Community ◽  
Plant Growth ◽  
Microbial Diversity ◽  
Growth And Yield ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Microbial Composition ◽  
Pyroligneous Acid ◽  
Plant Growth Promoting ◽  
Growth Promoting

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.

scholarly journals BACTERIAL DIVERSITY WITH PLANT GROWTH-PROMOTING POTENTIAL ISOLATED FROM Agave americana RHIZOSPHERE

2021 ◽  
Author(s):  
CLARA IVETTE RINCON-MOLINA ◽  
FRANCISCO ALEXANDER RINCON-MOLINA ◽  
ADALBERTO ZENTENO-ROJAS ◽  
VICTOR MANUEL RUIZ-VALDIVIEZO ◽  
JOSE MIGUEL CULEBRO-RICALDI ◽  
...  
Keyword(s):  
Plant Growth ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Rhizospheric Bacteria ◽  
Agave Americana ◽  
Plant Growth Promoting ◽  
Metagenomic Study ◽  
Growth Promoting ◽  
Native Strains ◽  
Potential Use

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.

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
Keyword(s):  
Hordeum Vulgare ◽  
Plant Growth ◽  
Tricalcium Phosphate ◽  
Future Application ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Bacterial Strains ◽  
Hordeum Vulgare L ◽  
Plant Growth Promoting ◽  
Growth Promoting

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.

scholarly journals Mucilaginibacter gossypii sp. nov. and Mucilaginibacter gossypiicola sp. nov., plant-growth-promoting bacteria isolated from cotton rhizosphere soils

2010 ◽  
Vol 60 (10) ◽  
pp. 2451-2457 ◽  
Author(s):  
Munusamy Madhaiyan ◽  
Selvaraj Poonguzhali ◽  
Jung-Sook Lee ◽  
Murugaiyan Senthilkumar ◽  
Keun Chul Lee ◽  
...  
Keyword(s):  
Plant Growth ◽  
Type Strain ◽  
Sequence Similarity ◽  
Extracellular Polysaccharide ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Separate Species ◽  
Genotypic Analysis ◽  
Plant Growth Promoting ◽  
Growth Promoting

Two isolates from rhizosphere soil of cotton, designated Gh-67T and Gh-48T, which produced large amounts of extracellular polysaccharide and possessed plant-growth-promoting traits, were characterized phenotypically and genotypically. The strains were Gram-negative and cells were non-motile rods that grew optimally at 28 °C and grew between pH 4 and 7. 16S rRNA gene sequence analysis of strains Gh-67T and Gh-48T placed them in the genus Mucilaginibacter, with pairwise sequence similarity between them and type strains from related genera ranging from 93.9 to 98.2 %. The major fatty acids were iso-C15 : 0, C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH). The strains contained MK-7 as the major isoprenoid quinone. The DNA G+C contents of strains Gh-67T and Gh-48T were 46.7 and 44.2 mol%, respectively. The low DNA–DNA hybridization value (18 %) and a number of phenotypic differences between strains Gh-48T and Gh-67T indicated that they represent two separate species. Results of phenotypic, phylogenetic and genotypic analysis revealed that the strains were separated from the species of Mucilaginibacter described to date. Therefore, strains Gh-67T and Gh-48T represent novel species of Mucilaginibacter, for which we propose the names Mucilaginibacter gossypii sp. nov. (type strain Gh-67T =NCIMB 14470T =KCTC 22380T) and Mucilaginibacter gossypiicola sp. nov. (type strain Gh-48T =NCIMB 14471T =KCTC 22379T).

scholarly journals Endophytic bacteria associated with tissue culture and leaves of Plinia peruviana

2020 ◽  
Vol 55 ◽  
Author(s):  
Eder Gonçalves Queiroz ◽  
Juliana Degenhardt ◽  
Marguerite Quoirin ◽  
Krisle da Silva
Keyword(s):  
Tissue Culture ◽  
Plant Growth ◽  
Endophytic Bacteria ◽  
Nodal Segments ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Bacillus Sp ◽  
Indolic Compounds ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract: The objective of this work was to isolate endophytic bacteria from tissue culture and leaves of jaboticaba (Plinia peruviana) and to evaluate their potential as plant growth-promoting bacteria. The bacteria were isolated from nodal segments grown in vitro and from leaves from a tree under natural conditions, totaling 11 and 54 isolates, respectively. The isolates were characterized by colony morphology. The indolic compounds produced by the isolates, in the presence or absence of 100 mg L-1 tryptophan, were quantified. The greatest producers of these compounds were identified by sequencing the 16S rRNA gene and were inoculated on jaboticaba seeds, using Azospirillum brasilense (Ab-V6) as a positive control. The sensitivity of bacteria to eight antibiotics was also evaluated. All assessed bacteria produced indolic compounds, especially Bacillus sp., with a content of 27.41 μg mL-1. The germination rate of the seeds inoculated with Stenotrophomonas sp. was high - 97.34% compared with that of 74.67% of the negative control. Bacillus sp. and Stenotrophomonas sp. also sped up germination. Chloramphenicol limited the growth of 82% of the isolates, followed by amoxicillin, gentamicin, levofloxacin, and tetracycline, which limited 70%; erythromycin was only effective against 35%. The endophytic bacteria isolated from jaboticaba show characteristics of plant growth-promoting bacteria, and Bacillus sp. and Stenotrophomonas sp., obtained from tissue culture, are capable of enhancing jaboticaba seed germination.

scholarly journals The use of bacterial indol-3-acetic acid (IAA) for reduce of chemical fertilizers doses

2017 ◽  
Vol 71 (3) ◽  
pp. 195-200 ◽  
Author(s):  
Snezana Djordjevic ◽  
Dragana Stanojevic ◽  
Milka Vidovic ◽  
Violeta Mandic ◽  
Ivana Trajkovic
Keyword(s):  
Acetic Acid ◽  
Plant Growth ◽  
Pcr Amplification ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Bacterial Strains ◽  
Chemical Fertilizers ◽  
Positive Effects ◽  
Plant Growth Promoting ◽  
Growth Promoting

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.

scholarly journals Isolation and characterization of bacteria from tomato and assessment of its plant growth-promoting traits in three economically important crops in Al-Ahsa region, Saudi Arabia

2021 ◽  
Vol 42 (4) ◽  
pp. 973-981
Author(s):  
M.F. Aldayel ◽  
◽  
A. Khalifa ◽  
Keyword(s):  
Saudi Arabia ◽  
Salt Stress ◽  
16S Rrna ◽  
Plant Growth ◽  
Rrna Gene ◽  
Eruca Sativa ◽  
Plant Growth Promoting ◽  
Number Of Leaves ◽  
Growth Promoting ◽  
Plant Growth Promoting Traits

Aim: This study aimed to isolate, characterize and assess the plant growth-promoting traits of bacterial isolates inhabiting the rhizosphere of Solanum lycopersicum L. (tomato) against three plants—Eruca sativa, Lepidium sativum and Raphanus sativum—from Saudi Arabia's Al-Ahsa region. Methodology: bacterial isolate designated as SLK10 was obtained from the rhizosphere of tomato grown in the Al-Ahsa region, Saudi Arabia. SLK10 was further characterized morphologically, biochemically and genotypically using 16S rRNA gene sequencing. The roles in alleviating salt stress effects on three important economic crops were also assessed by implementing a cross-inoculation strategy. Results: SLK10 formed a circular, non-pigmented and raised colony with an entire margin. The cells were rod shaped and Gram negative. SLK10 displayed multiple plant growth-stimulating features, such as the solubilization of inorganic phosphate and the production of phytohormones and acetoin. Comparative sequence analysis of 16S rRNA gene revealed that SLK10 belonged to Pseudomonas monteilii, to which it exhibited 99.86% sequence homology. SLK10 significantly promoted the length of primary root, stem and number of leaves in Eruca sativa, Lepidium sativumand Raphanus sativus growing under 1000 ppm salt stress. The number of leaves in L. sativum and R. sativus growing under 2000 ppm salt stress was substantially enhanced by SLK10. Interpretation: SLK10 is a plant growth-promoting bacterium and can be used as a green fertilizer to increase soil fertility and plant productivity in the Eastern region of Saudi Arabia.

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