Differential Protein Expression Analysis of Two Sugarcane Varieties in Response to Diazotrophic Plant Growth-Promoting Endophyte Enterobacter roggenkampii ED5

Plant endophytic bacteria have many vital roles in plant growth promotion (PGP), such as nitrogen (N) fixation and resistance to biotic and abiotic stresses. In this study, the seedlings of sugarcane varieties B8 (requires a low concentration of nitrogen for growth) and GT11 (requires a high concentration of nitrogen for growth) were inoculated with endophytic diazotroph Enterobacter roggenkampii ED5, which exhibits multiple PGP traits, isolated from sugarcane roots. The results showed that the inoculation with E. roggenkampii ED5 promoted the growth of plant significantly in both sugarcane varieties. 15N detection at 60 days post-inoculation proved that the inoculation with strain ED5 increased the total nitrogen concentration in the leaf and root than control in both sugarcane varieties, which was higher in B8. Biochemical parameters and phytohormones in leaf were analyzed at 30 and 60 days after the inoculation. The results showed that the inoculation with E. roggenkampii ED5 improved the activities of superoxide dismutase (SOD), catalase (CAT), NADH-glutamate dehydrogenase (NADH-GDH), glutamine synthetase (GS), and endo-β-1,4-glucanase, and the contents of proline and indole acetic acid (IAA) in leaf, and it was generally more significant in B8 than in GT11. Tandem Mass Tags (TMT) labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to perform comparative proteomic analysis in the sugarcane leaves at 30 days after inoculation with strain ED5. A total of 27,508 proteins were detected, and 378 differentially expressed proteins (DEPs) were found in the treated sugarcane variety B8 (BE) as compared to control (BC), of which 244 were upregulated and 134 were downregulated. In contrast, a total of 177 DEPs were identified in the treated sugarcane variety GT11 (GE) as compared to control (GC), of which 103 were upregulated and 74 were downregulated. The DEPs were associated with nitrogen metabolism, photosynthesis, starch, sucrose metabolism, response to oxidative stress, hydrolase activity, oxidative phosphorylation, glutathione metabolism, phenylpropanoid metabolic process, and response to stresses in Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database. To the best of our knowledge, this is the first proteomic approach to investigate the molecular basis of the interaction between N-fixing endophytic strain E. roggenkampii ED5 and sugarcane.

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Gluconacetobacter diazotrophicus Pal5 Enhances Plant Robustness Status under the Combination of Moderate Drought and Low Nitrogen Stress in Zea mays L.

Microorganisms ◽

10.3390/microorganisms9040870 ◽

2021 ◽

Vol 9 (4) ◽

pp. 870

Author(s):

Muhammad Aammar Tufail ◽

María Touceda-González ◽

Ilaria Pertot ◽

Ralf-Udo Ehlers

Keyword(s):

Zea Mays ◽

Plant Growth ◽

Zea Mays L ◽

Growth Promotion ◽

Nitrogen Stress ◽

Rrna Gene ◽

N Fixation ◽

Gluconacetobacter Diazotrophicus ◽

Maize Plants ◽

Low Nitrogen

Plant growth promoting endophytic bacteria, which can fix nitrogen, plays a vital role in plant growth promotion. Previous authors have evaluated the effect of Gluconacetobacter diazotrophicus Pal5 inoculation on plants subjected to different sources of abiotic stress on an individual basis. The present study aimed to appraise the effect of G. diazotrophicus inoculation on the amelioration of the individual and combined effects of drought and nitrogen stress in maize plants (Zea mays L.). A pot experiment was conducted whereby treatments consisted of maize plants cultivated under drought stress, in soil with a low nitrogen concentration and these two stress sources combined, with and without G. diazotrophicus seed inoculation. The inoculated plants showed increased plant biomass, chlorophyll content, plant nitrogen uptake, and water use efficiency. A general increase in copy numbers of G. diazotrophicus, based on 16S rRNA gene quantification, was detected under combined moderate stress, in addition to an increase in the abundance of genes involved in N fixation (nifH). Endophytic colonization of bacteria was negatively affected by severe stress treatments. Overall, G. diazotrophicus Pal5 can be considered as an effective tool to increase maize crop production under drought conditions with low application of nitrogen fertilizer.

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Potassium mobilization and plant growth promotion by soil bacteria isolated from different agroclimatic zones of Odisha, India

Acta agriculturae Slovenica ◽

10.14720/aas.2021.117.1.1794 ◽

2021 ◽

Vol 117 (3) ◽

pp. 1

Author(s):

Aiswarya PANDA ◽

Ankita DASH ◽

Bibhuti Bhusan MISHRA

Keyword(s):

Plant Growth ◽

Inductively Coupled Plasma ◽

Growth Promotion ◽

Crop Productivity ◽

Shoot Length ◽

Emission Spectrometry ◽

Potassium Accumulation ◽

Pgp Traits ◽

Soil Potassium ◽

Agroclimatic Zones

<p class="042abstractstekst"><span lang="EN-US">Potassium is essential for plant metabolism; improves immunity to stress and increase crop productivity. Soil contains insoluble form of potassium, which is unavailable for plant absorption. Potash mobilizing bacteria (KMB) solubilise complex potassium and make it available to plant. KMB with plant growth promoting (PGP) traits could enhance growth and crop productivity. Here we attempt to screen KMBs with PGP traits from different agroclimatic zones of Odisha and study dynamics of potassium in soil. Isolation of KMB and determination of PGP traits was performed with standard protocols. Pot culture experiment was aimed to study their effect on sunflower crop. Available soil potassium was quantified using inductively coupled plasma-optical emission spectrometry (ICP-OES). Thirty KMBs were isolated from different agro-climatic zones of Odisha, out of which 6 isolates exhibited maximum PGP traits. Moreover, after adding inoculums the available soil potassium decreased over 0 to 30 days as compared to control, with increase in shoot length. T7 (consortium) reported maximum (144 %) increase in shoot length. Available soil potassium content decreased with increase in time. A maximum decrease was reported in T7 (26.31 %), suggesting potassium accumulation by plant.</span></p>

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

Journal of Applied and Natural Science ◽

10.31018/jans.v9i3.1359 ◽

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.

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

BioMed Research International ◽

10.1155/2013/491091 ◽

2013 ◽

Vol 2013 ◽

pp. 1-17 ◽

Cited By ~ 27

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.

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

Microorganisms ◽

10.3390/microorganisms8040499 ◽

2020 ◽

Vol 8 (4) ◽

pp. 499 ◽

Cited By ~ 2

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.

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Plant Growth Promotion Diversity in Switchgrass-Colonizing, Diazotrophic Endophytes

Frontiers in Microbiology ◽

10.3389/fmicb.2021.730440 ◽

2021 ◽

Vol 12 ◽

Author(s):

Sara Gushgari-Doyle ◽

Marcus Schicklberger ◽

Yifan V. Li ◽

Robert Walker ◽

Romy Chakraborty

Keyword(s):

Plant Growth ◽

Panicum Virgatum ◽

Growth Promotion ◽

Pgp Traits ◽

Isolation And Characterization ◽

Plant Growth Promoting ◽

Cultivation Methods ◽

Diazotrophic Endophytes ◽

Raoultella Terrigena

Endophytic nitrogen-fixing (diazotrophic) bacteria are essential members of the microbiome of switchgrass (Panicum virgatum), considered to be an important commodity crop in bioenergy production. While endophytic diazotrophs are known to provide fixed atmospheric nitrogen to their host plant, there are many other plant growth-promoting (PGP) capabilities of these organisms to be demonstrated. The diversity of PGP traits across different taxa of switchgrass-colonizing endophytes is understudied, yet critical for understanding endophytic function and improving cultivation methods of important commodity crops. Here, we present the isolation and characterization of three diazotrophic endophytes: Azospirillum agricola R1C, Klebsiella variicola F10Cl, and Raoultella terrigena R1Gly. Strains R1C and F10Cl were isolated from switchgrass and strain R1Gly, while isolated from tobacco, is demonstrated herein to colonize switchgrass. Each strain exhibited highly diverse genomic and phenotypic PGP capabilities. Strain F10Cl and R1Gly demonstrated the highest functional similarity, suggesting that, while endophyte community structure may vary widely based on host species, differences in functional diversity are not a clearly delineated. The results of this study advance our understanding of diazotrophic endophyte diversity, which will allow us to design robust strategies to improve cultivation methods of many economically important commodity crops.

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Characterization of Streptomyces spp. from Rice Fields as a Potential Biocontrol Agent against Burkholderia glumae and Rice Plant Growth Promoter

Agronomy ◽

10.3390/agronomy11091850 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1850

Author(s):

Mohamad Syazwan Ngalimat ◽

Erneeza Mohd Hata ◽

Dzarifah Zulperi ◽

Siti Izera Ismail ◽

Mohd Razi Ismail ◽

...

Keyword(s):

Plant Growth ◽

Plant Growth Promotion ◽

Biocontrol Agent ◽

Growth Promotion ◽

Antagonistic Activity ◽

Rice Fields ◽

Burkholderia Glumae ◽

Pgp Traits ◽

Genus Streptomyces ◽

Streptomyces Sp

The usage of plant growth-promoting (PGP) Streptomyces to improve plant growth is an alternative to existing strategies of chemical fertilizers that commonly caused environmental pollution. The aim of this study was to isolate and characterize PGP Streptomyces from Malaysian rice fields with antagonistic activity against Bacterial Panicle Blight disease in rice caused by Burkholderia glumae. A total of 50 bacterial isolates were recovered from the soil, rhizosphere, and endosphere; 22% showed antagonistic activity against B. glumae. Molecular identification using 16S rRNA amplification and phylogenetic tree analyses revealed that the antagonistic isolates belonged to the genus Streptomyces. Among the antagonistic isolates, Streptomyces sp. TBS5 (26.35 ± 0.14 mm) demonstrated the most antagonistic activity (p < 0.05) against B. glumae. Through API® ZYM analysis, the antagonistic isolates were revealed to have phosphoric hydrolase, ester hydrolase, peptide hydrolase, and glycosidase activities that play a crucial role in plant growth promotion. The antagonistic isolates demonstrated the highest (80%) PGP traits including able to fix nitrogen and solubilize phosphate, as well as produce siderophore and indole-3-acetic acid. Plant growth promotion assay under laboratory and greenhouse conditions were analyzed with the treatment of rice, Oryza sativa, seeds with the antagonistic isolates. Seeds treated with Streptomyces sp. TBS5, JAS2, R2-7, and TKR8 showed improvement in vigor index by more than 100% compared to water-treated control plants under both conditions. Augmentation of root length showed an overall increment of more than 101.5% under laboratory condition and 151.9% under greenhouse condition using Streptomyces sp. TBS5, JAS2, R2-7, and TKR8 treatments. Results suggest that Streptomyces sp. TBS5, JAS2, R2-7, and TKR8 are a good candidate to be developed as both biocontrol agent against B. glumae and PGP agent in rice.

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Plant Growth Promoting Abilities of Novel Burkholderia-Related Genera and Their Interactions With Some Economically Important Tree Species

Frontiers in Sustainable Food Systems ◽

10.3389/fsufs.2021.618305 ◽

2021 ◽

Vol 5 ◽

Author(s):

Munusamy Madhaiyan ◽

Govindan Selvakumar ◽

Tan HianHwee Alex ◽

Lin Cai ◽

Lianghui Ji

Keyword(s):

Plant Growth ◽

Oil Palm ◽

Tree Species ◽

Growth Promotion ◽

Nitrogenase Activity ◽

Acc Deaminase ◽

Bacterial Strains ◽

Pgp Traits ◽

Plant Growth Promoting ◽

Promote Plant Growth

A survey of bacterial endophytes associated with the leaves of oil palm and acacias resulted in the isolation of 19 bacterial strains belonging to the genera Paraburkholderia, Caballeronia, and Chitinasiproducens, which are now regarded as distinctively different from the parent genus Burkholderia. Most strains possessed one or more plant growth promotion (PGP) traits although nitrogenase activity was present in only a subset of the isolates. The diazotrophic Paraburkholderia tropica strain S39-2 with multiple PGP traits and the non-diazotrophic Chitinasiproducens palmae strain JS23T with a significant level of 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity were selected to investigate the influence of bacterial inoculation on some economically important tree species. Microscopic examination revealed that P. tropica S39-2 was rhizospheric as well as endophytic while C. palmae JS23T was endophytic. P. tropica strain S39-2 significantly promoted the growth of oil palm, eucalyptus, and Jatropha curcas. Interestingly, the non-diazotrophic, non-auxin producing C. palmae JS23T strain also significantly promoted the growth of oil palm and eucalyptus although it showed negligible effect on J. curcas. Our results suggest that strains belonging to the novel Burkholderia-related genera widely promote plant growth via both N-independent and N-dependent mechanisms. Our results also suggest that the induction of defense response may prevent the colonization of an endophyte in plants.

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Bioprospecting desert plant Bacillus endophytic strains for their potential to enhance plant stress tolerance

Scientific Reports ◽

10.1038/s41598-019-54685-y ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 8

Author(s):

Ameerah Bokhari ◽

Magbubah Essack ◽

Feras F. Lafi ◽

Cristina Andres-Barrao ◽

Rewaa Jalal ◽

...

Keyword(s):

Salt Stress ◽

Plant Growth ◽

Growth Promotion ◽

Stress Conditions ◽

Desert Plant ◽

Plant Growth Promoting Bacteria ◽

Fresh Weight ◽

Pgp Traits ◽

Plant Growth Promoting ◽

Growth Promoting

AbstractPlant growth-promoting bacteria (PGPB) are known to increase plant tolerance to several abiotic stresses, specifically those from dry and salty environments. In this study, we examined the endophyte bacterial community of five plant species growing in the Thar desert of Pakistan. Among a total of 368 culturable isolates, 58 Bacillus strains were identified from which the 16 most divergent strains were characterized for salt and heat stress resilience as well as antimicrobial and plant growth-promoting (PGP) activities. When the 16 Bacillus strains were tested on the non-host plant Arabidopsis thaliana, B. cereus PK6-15, B. subtilis PK5-26 and B. circulans PK3-109 significantly enhanced plant growth under salt stress conditions, doubling fresh weight levels when compared to uninoculated plants. B. circulans PK3-15 and PK3-109 did not promote plant growth under normal conditions, but increased plant fresh weight by more than 50% when compared to uninoculated plants under salt stress conditions, suggesting that these salt tolerant Bacillus strains exhibit PGP traits only in the presence of salt. Our data indicate that the collection of 58 plant endophytic Bacillus strains represents an important genomic resource to decipher plant growth promotion at the molecular level.

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Screening of efficient rhizobacteria associated with cauliflower (Brassica oleraceavar. botrytis L.) for plant growth promoting traits

Journal of Applied and Natural Science ◽

10.31018/jans.v9i1.1166 ◽

2017 ◽

Vol 9 (1) ◽

pp. 167-172

Author(s):

Sonal Bhardwaj ◽

Bhawna Dipta ◽

Shruti Kirti ◽

Rajesh Kaushal

Keyword(s):

Plant Growth ◽

Growth Promotion ◽

Himachal Pradesh ◽

Pgp Traits ◽

Antifungal Metabolites ◽

Stalk Rot ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Phosphate Solubilizing

In the current study, a total of 25 isolates were isolated from the rhizosphere and roots of cauliflower (Brassica oleraceavar. botrytis L.) from the vicinity of Una district of Himachal Pradesh. The isolates were tested in vitro for their ability to solubilise phosphorous and produce siderophore, indole acetic acid (IAA), hydrogen cyanide (HCN) and antifungal metabolites against the soil borne pathogens. Results revealed that out of 25, only 4 rhizospheric isolates (SB5, SB11, SB8 and SB10) have maximum plant growth promoting attributes. The isolates were identified as Bacillus sp. on the basis of Bergey’s manual of systematic bacteriology. The isolate SB11 recorded highest phosphate solubilizing efficiency in solid medium (109.09%) and in liquid medium (350μg/ml). Maximum production of IAA (51.96μg/ml), siderophore (91.41%) and HCN were also observed for the same isolate. Further-more, the isolate SB11 produced highest antifungal metabolite production against Rhizoctoniasolani(37.11%), Sclerotiniasclerotiorum(41.11%), and Pythium sp. (71.11%) causing root rot, stalk rot and damping off diseases in cauliflower, respectively. The selected isolate (SB11) showed optimum growth at a pH of 7.0, 35°C temperature and 2% NaCl. On the basis of multifarious PGP-traits the SB11 isolate has tremendous potential to be used as a bioferti-lizer/bioprotectant for growth promotion and natural protection of cauliflower under low hill conditions of Himachal Pradesh.

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