scholarly journals Diazotrophic bacteria from maize exhibit multifaceted plant growth promotion traits in multiple hosts

2020 ◽  
Author(s):  
Shawn M. Higdon ◽  
Tania Pozzo ◽  
Emily J. Tibbett ◽  
Colleen Chiu ◽  
Richard Jeannotte ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Marker Genes ◽  
Diazotrophic Bacteria ◽  
In Planta ◽  
Pgp Traits

AbstractSierra Mixe maize is a geographically remote landrace variety grown on nitrogen-deficient fields in Oaxaca, Mexico that meets its nutritional requirements without synthetic fertilizer by associating with free-living diazotrophs comprising the microbiota of its aerial root mucilage. We selected nearly 500 diazotrophic bacteria isolated from Sierra Mixe maize mucilage and sequenced their genomes. Comparative genomic analysis demonstrated that isolates represented diverse genera and possessed multiple marker genes for mechanisms of direct plant growth promotion (PGP). In addition to nitrogen fixation, we examined deamination of 1-amino-1-cyclopropanecarboxylic acid, biosynthesis of indole-3-acetic acid, and phosphate solubilization. Implementing in vitro colorimetric assays revealed each isolate’s potential to confer the alternative PGP activities that corroborated genotype and pathway content. We examined the ability of mucilage diazotrophs to confer PGP by direct inoculation of clonally propagated potato plants in planta, which led to the identification of bio-stimulant candidates that were tested for PGP by inoculating a conventional maize variety. The results indicate that, while many diazotrophic isolates from Sierra Mixe maize possessed genotypes and in vitro phenotypes for targeted PGP traits, a subset of these organisms promoted the growth of potato and conventional maize using multiple promotion mechanisms.

scholarly journals Exploitation of endophytic Pseudomonas sp. for plant growth promotion and colonization in rice

2017 ◽  
Vol 9 (3) ◽  
pp. 1310-1316
Author(s):  
Gurjot Kaur ◽  
Poonam Sharma ◽  
Deepika Chhabra ◽  
Kailash Chand ◽  
Gurjit Singh Mangat
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Acc Deaminase ◽  
Pseudomonas Sp ◽  
Bacterial Isolates ◽  
Pgp Traits ◽  
P Solubilization ◽  
Fluorescent Pigment

The present investigation was carried out to exploit bacterial endophytes associated with root and leaf tissue of rice plant for plant growth promotion (PGP) and colonization study in vitro. Total 10 endophytic bacterial isolates (Pseudomonas sp.) were evaluate for PGP traits like P solubilization, production of Indole acetic acid (IAA), siderophore, ACC deaminase, protease, cellulase, fluorescent pigment, urease and denitrification activity. Out of 10 endophytic bacteria 30 %, 60 %, 20 %, 70 %, 10 % and 10 % were positive for siderophore, protease, cellulase, fluorescent pigment, urease and denitrification respectively. Maximum IAA production was recorded with isolate LRBLE7 (18.8 μgml-1) followed by LRBRE4 (16.0 μgml-1) and maximum P-solubilization was recorded with isolate LRBRE4 (5.8 mg 100 ml-1) followed by LRBLE7 (4.4 mg 100 ml-1). ACC deaminase production was recorded with isolate LRBLE6 (O.D=0.352 nm) followed by LRBRE5 (O.D=0.324nm). Three potential isolates (LRBRE4, LRBRE6 and LRBLE7) were selected on the basis of multiple PGP traits and were subjected to colonization study of rice seedling in vitro. Potential bacterial isolates can be exploited for improving growth and productivity in rice under sustainable management system.

scholarly journals Genomic Analysis of the 1-Aminocyclopropane-1-Carboxylate Deaminase-Producing Pseudomonas thivervalensis SC5 Reveals Its Multifaceted Roles in Soil and in Beneficial Interactions With Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Francisco X. Nascimento ◽  
Paola Urón ◽  
Bernard R. Glick ◽  
Admir Giachini ◽  
Márcio J. Rossi
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Pseudomonas Syringae ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Genomic Analysis ◽  
Acc Deaminase ◽  
Quorum Quenching ◽  
Cucumber Plant

Beneficial 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing bacteria promote plant growth and stress resistance, constituting a sustainable alternative to the excessive use of chemicals in agriculture. In this work, the increased plant growth promotion activity of the ACC deaminase-producing Pseudomonas thivervalensis SC5, its ability to limit the growth of phytopathogens, and the genomics behind these important properties are described in detail. P. thivervalensis SC5 displayed several active plant growth promotion traits and significantly increased cucumber plant growth and resistance against salt stress (100mmol/L NaCl) under greenhouse conditions. Strain SC5 also limited the in vitro growth of the pathogens Botrytis cinerea and Pseudomonas syringae DC3000 indicating active biological control activities. Comprehensive analysis revealed that P. thivervalensis SC5 genome is rich in genetic elements involved in nutrient acquisition (N, P, S, and Fe); osmotic stress tolerance (e.g., glycine-betaine, trehalose, and ectoine biosynthesis); motility, chemotaxis and attachment to plant tissues; root exudate metabolism including the modulation of plant phenolics (e.g., hydroxycinnamic acids), lignin, and flavonoids (e.g., quercetin); resistance against plant defenses (e.g., reactive oxygens species-ROS); plant hormone modulation (e.g., ethylene, auxins, cytokinins, and salicylic acid), and bacterial and fungal phytopathogen antagonistic traits (e.g., 2,4-diacetylphloroglucinol, HCN, a fragin-like non ribosomal peptide, bacteriocins, a lantipeptide, and quorum-quenching activities), bringing detailed insights into the action of this versatile plant-growth-promoting bacterium. Ultimately, the combination of both increased plant growth promotion/protection and biological control abilities makes P. thivervalensis SC5 a prime candidate for its development as a biofertilizer/biostimulant/biocontrol product. The genomic analysis of this bacterium brings new insights into the functioning of Pseudomonas and their role in beneficial plant-microbe interactions.

scholarly journals Endophytic Bacterial Isolates From Halophytes Demonstrate Phytopathogen Biocontrol and Plant Growth Promotion Under High Salinity

2021 ◽  
Vol 12 ◽  
Author(s):  
Christos A. Christakis ◽  
Georgia Daskalogiannis ◽  
Anastasia Chatzaki ◽  
Emmanouil A. Markakis ◽  
Glykeria Mermigka ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
High Salinity ◽  
Growth Promotion ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
In Planta ◽  
Promoting Effect ◽  
Cakile Maritima

Halophytic endophytes potentially contribute to the host’s adaptation to adverse environments, improving its tolerance against various biotic and abiotic stresses. Here, we identified the culturable endophytic bacteria of three crop wild relative (CWR) halophytes: Cakile maritima, Matthiola tricuspidata, and Crithmum maritimum. In the present study, the potential of these isolates to improve crop adaptations to various stresses was investigated, using both in vitro and in-planta approaches. Endophytic isolates were identified by their 16S rRNA gene sequence and evaluated for their ability to: grow in vitro in high levels of NaCl; inhibit the growth of the economically important phytopathogens Verticillium dahliae, Ralstonia solanacearum, and Clavibacter michiganensis and the human pathogen Aspergillus fumigatus; provide salt tolerance in-planta; and provide growth promoting effect in-planta. Genomes of selected isolates were sequenced. In total, 115 endophytic isolates were identified. At least 16 isolates demonstrated growth under increased salinity, plant growth promotion and phytopathogen antagonistic activity. Three showed in-planta suppression of Verticillium growth. Furthermore, representatives of three novel species were identified: two Pseudomonas species and one Arthrobacter. This study provides proof-of-concept that the endophytes from CWR halophytes can be used as “bio-inoculants,” for the enhancement of growth and stress tolerance in crops, including the high-salinity stress.

EFFICACY OF RHIZOBACTERIA ON PLANT GROWTH PROMOTION AND DISEASE SUPPRESSION IN VITRO

2012 ◽  
pp. 525-532 ◽  
Author(s):  
S. Velivelli ◽  
E. O'Herlihy ◽  
B. Janczura ◽  
B. Doyle Prestwich ◽  
J. Ghyselinck ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Disease Suppression

scholarly journals Multifarious Indigenous Diazotrophic Rhizobacteria of Rice (Oryza sativa L.) Rhizosphere and Their Effect on Plant Growth Promotion

2022 ◽  
Vol 8 ◽  
Author(s):  
Mohammad Imran Mir ◽  
Bee Hameeda ◽  
Humera Quadriya ◽  
B. Kiran Kumar ◽  
Noshin Ilyas ◽  
...  
Keyword(s):  
Plant Growth ◽  
Phosphate Solubilization ◽  
Nitrogenase Activity ◽  
Hydrolytic Enzymes ◽  
Seed Vigor ◽  
Bacterial Isolates ◽  
Diazotrophic Bacteria ◽  
Pgp Traits ◽  
Rice Plants

A diverse group of rhizobacteria persists in the rhizospheric soil, on the surface of roots, or in association with rice plants. These bacteria colonize plant root systems, enhance plant growth and crop yield. Indigenous rhizobacteria are known to promote soil health, grain production quality and serve as sustainable bioinoculant. The present study was aimed to isolate, identify and characterize indigenous plant growth promoting (PGP) diazotrophic bacteria associated with the rhizosphere of rice fields from different areas of Jammu and Kashmir, India. A total of 15 bacteria were isolated and evaluated for various PGP traits, antagonistic activity against phytopathogens, production of hydrolytic enzymes and biofilm formation under in-vitro conditions. The majority of the isolated bacteria were Gram-negative. Out of 15 bacterial isolates, nine isolates produced IAA (12.24 ± 2.86 to 250.3 ± 1.15 μg/ml), 6 isolates exhibited phosphate solubilization activity (36.69 ± 1.63 to 312.4 ± 1.15 μg/ml), 7 isolates exhibited rock phosphate solubilization while 5 isolates solubilized zinc (10–18 mm), 7 isolates showed siderophore production, 8 isolates exhibited HCN production, 6 isolates exhibited aminocyclopropane-1-carboxylate (ACC) deaminase activity, 13 isolates exhibited cellulase activity, nine isolates exhibited amylase and lipase activity and six isolates exhibited chitinase activity. In addition, 5 isolates showed amplification with the nifH gene and showed a significant amount of nitrogenase activity in a range of 0.127–4.39 μmol C2H4/mg protein/h. Five isolates viz., IHK-1, IHK-3, IHK-13, IHK-15 and IHK-25 exhibited most PGP attributes and successfully limited the mycelial growth of Rhizoctonia solani and Fusarium oxysporum in-vitro. All the five bacterial isolates were identified based on morphological, biochemical and 16S rDNA gene sequencing study, as Stenotrophomonas maltophilia, Enterobacter sp., Bacillus sp., Ochrobactrum haematophilum and Pseudomonas aeruginosa. Rice plants developed from seeds inoculated with these PGP strains individually had considerably higher germination percentage, seed vigor index and total dry biomass when compared to control. These findings strongly imply that the PGP diazotrophic bacteria identified in this work could be employed as plant growth stimulators in rice.

scholarly journals Potential for Plant Growth Promotion of Rhizobacteria Associated withSalicorniaGrowing in Tunisian Hypersaline Soils

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Francesca Mapelli ◽  
Ramona Marasco ◽  
Eleonora Rolli ◽  
Marta Barbato ◽  
Hanene Cherif ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Crop Production ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Growth Promotion ◽  
Arid Ecosystems ◽  
Acetic Acid Production ◽  
Halotolerant Bacteria ◽  
Microbiome Composition

Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres ofSalicorniaplants and bulk soils were collected fromSebkhetandChotthypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated withSalicorniaroot system. A large collection of 475 halophilic and halotolerant bacteria was established fromSalicorniarhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP) features. TwentyHalomonasstrains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activitiesin vitroat 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using agfp-labelled strain it was possible to demonstrate thatHalomonasis capable of successfully colonisingSalicorniaroots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.

scholarly journals Plant Growth Promotion Potential Is Equally Represented in Diverse Grapevine Root-Associated Bacterial Communities from Different Biopedoclimatic Environments

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Ramona Marasco ◽  
Eleonora Rolli ◽  
Marco Fusi ◽  
Ameur Cherif ◽  
Ayman Abou-Hadid ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Plant Growth ◽  
Bacterial Communities ◽  
Growth Promotion ◽  
Rrna Gene ◽  
Similar Distribution ◽  
Bacterial Assemblage ◽  
Pgp Traits ◽  
Associated Bacteria

Plant-associated bacteria provide important services to host plants. Environmental factors such as cultivar type and pedoclimatic conditions contribute to shape their diversity. However, whether these environmental factors may influence the plant growth promoting (PGP) potential of the root-associated bacteria is not widely understood. To address this issue, the diversity and PGP potential of the bacterial assemblage associated with the grapevine root system of different cultivars in three Mediterranean environments along a macrotransect identifying an aridity gradient were assessed by culture-dependent and independent approaches. According to 16S rRNA gene PCR-DGGE, the structure of endosphere and rhizosphere bacterial communities was highly diverse (P=0.03) and was associated with a cultivar/latitudinal/climatic effect. Despite being diverse, the bacterial communities associated with Egyptian grapevines shared a higher similarity with the Tunisian grapevines than those cultivated in North Italy. A similar distribution, according to the cultivar/latitude/aridity gradients, was observed for the cultivable bacteria. Many isolates (23%) presentedin vitromultiple stress resistance capabilities and PGP activities, the most frequent being auxin synthesis (82%), insoluble phosphate solubilisation (61%), and ammonia production (70%). The comparable numbers and types of potential PGP traits among the three different environmental settings indicate a strong functional homeostasis of beneficial bacteria associated with grape root.

scholarly journals Diversity, Phylogeny and Plant Growth Promotion Traits of Nodule Associated Bacteria Isolated from Lotus parviflorus

2020 ◽  
Vol 8 (4) ◽  
pp. 499 ◽  
Author(s):  
Ricardo Soares ◽  
Jesús Trejo ◽  
Maria J. Lorite ◽  
Etelvina Figueira ◽  
Juan Sanjuán ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Root Nodules ◽  
Nifh Gene ◽  
Bacterial Strains ◽  
Lytic Enzymes ◽  
Taxonomic Assignment ◽  
Pgp Traits ◽  
Associated Bacteria

Lotus spp. are widely used as a forage to improve pastures, and inoculation with elite rhizobial strains is a common practice in many countries. However, only a few Lotus species have been studied in the context of plant-rhizobia interactions. In this study, forty highly diverse bacterial strains were isolated from root nodules of wild Lotus parviflorus plants growing in two field locations in Portugal. However, only 10% of these isolates could nodulate one or more legume hosts tested, whereas 90% were thought to be opportunistic nodule associated bacteria. Phylogenetic studies place the nodulating isolates within the Bradyrhizobium genus, which is closely related to B. canariense and other Bradyrhizobium sp. strains isolated from genistoid legumes and Ornithopus spp. Symbiotic nodC and nifH gene phylogenies were fully consistent with the taxonomic assignment and host range. The non-nodulating bacteria isolated were alpha- (Rhizobium/Agrobacterium), beta- (Massilia) and gamma-proteobacteria (Pseudomonas, Lysobacter, Luteibacter, Stenotrophomonas and Rahnella), as well as some bacteroidetes from genera Sphingobacterium and Mucilaginibacter. Some of these nodule-associated bacteria expressed plant growth promotion (PGP) traits, such as production of lytic enzymes, antagonistic activity against phytopathogens, phosphate solubilization, or siderophore production. This argues for a potential beneficial role of these L. parviflorus nodule-associated bacteria.

scholarly journals Isolation, Biochemical and Genomic Characterization of Glyphosate Tolerant Bacteria to Perform Microbe-Assisted Phytoremediation

2021 ◽  
Vol 11 ◽  
Author(s):  
Francisco Massot ◽  
Panagiotis Gkorezis ◽  
Jonathan Van Hamme ◽  
Damian Marino ◽  
Bojana Spirovic Trifunovic ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Large Scale ◽  
Agricultural Soils ◽  
Growth Promotion ◽  
Sole Source ◽  
Bacterial Strains ◽  
Positive Effects ◽  
Assisted Phytoremediation

The large-scale use of the herbicide glyphosate leads to growing ecotoxicological and human health concerns. Microbe-assisted phytoremediation arises as a good option to remove, contain, or degrade glyphosate from soils and waterbodies, and thus avoid further spreading to non-target areas. To achieve this, availability of plant-colonizing, glyphosate-tolerant and -degrading strains is required and at the same time, it must be linked to plant-microorganism interaction studies focusing on a substantive ability to colonize the roots and degrade or transform the herbicide. In this work, we isolated bacteria from a chronically glyphosate-exposed site in Argentina, evaluated their glyphosate tolerance using the minimum inhibitory concentration assay, their in vitro degradation potential, their plant growth-promotion traits, and performed whole genome sequencing to gain insight into the application of a phytoremediation strategy to remediate glyphosate contaminated agronomic soils. Twenty-four soil and root-associated bacterial strains were isolated. Sixteen could grow using glyphosate as the sole source of phosphorous. As shown in MIC assay, some strains tolerated up to 10000 mg kg–1 of glyphosate. Most of them also demonstrated a diverse spectrum of in vitro plant growth-promotion traits, confirmed in their genome sequences. Two representative isolates were studied for their root colonization. An isolate of Ochrobactrum haematophilum exhibited different colonization patterns in the rhizoplane compared to an isolate of Rhizobium sp. Both strains were able to metabolize almost 50% of the original glyphosate concentration of 50 mg l–1 in 9 days. In a microcosms experiment with Lotus corniculatus L, O. haematophilum performed better than Rhizobium, with 97% of glyphosate transformed after 20 days. The results suggest that L. corniculatus in combination with to O. haematophilum can be adopted for phytoremediation of glyphosate on agricultural soils. An effective strategy is presented of linking the experimental data from the isolation of tolerant bacteria with performing plant-bacteria interaction tests to demonstrate positive effects on the removal of glyphosate from soils.

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