scholarly journals In Vitro Evaluation and Genome Mining of Bacillus subtilis Strain RS10 Reveals Its Biocontrol and Plant Growth-Promoting Potential

Agriculture ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1273
Author(s):  
Sajid Iqbal ◽  
Nimat Ullah ◽  
Hussnain Ahmed Janjua
Keyword(s):  
Bacillus Subtilis ◽  
Plant Growth ◽  
Genome Analysis ◽  
Growth Promotion ◽  
Gene Clusters ◽  
Subtilis Strain ◽  
Antifungal Metabolites ◽  
Plant Growth Promoting ◽  
Growth Promoting

Recently, crop management has involved excessive use of chemical fertilizers and pesticides, compromising public health and environmental integrity. Rhizobacteria, which can enhance plant growth and protect plants from phytopathogen, are eco-friendly and have been attracting increasing attention. In the current study, Bacillus subtilis RS10 isolated from the rhizosphere region of Cynodon dactylon, inhibited the growth of indicator strains and exhibited in vitro plant growth-promoting traits. A whole-genome analysis identified numerous biosynthetic gene clusters encoding antibacterial and antifungal metabolites including bacillibactin, bogorol A, fengycin, bacteriocin, type III polyketides (PKs), and bacilysin. The plant growth-promoting conferring genes involved in nitrogen metabolism, phosphate solubilization, hydrogen sulfide, phytohormones, siderophore biosynthesis, chemotaxis and motility, plant root colonization, lytic enzymes, and biofilm formation were determined. Furthermore, genes associated with abiotic stresses such as high salinity and osmotic stress were identified. A comparative genome analysis indicated open pan-genome and the strain was identified as a novel sequence type (ST-176). In addition, several horizontal gene transfer events were found which putatively play a vital role in the evolution and new functionalities of a strain. In conclusion, the current study demonstrates the potential of RS10 antagonism against important pathogens and plant growth promotion, highlighting its application in sustainable agriculture.

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

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.

scholarly journals Genomic and Metabolomic Insights into Secondary Metabolites of the Novel Bacillus halotolerans Hil4, an Endophyte with Promising Antagonistic Activity against Gray Mold and Plant Growth Promoting Potential

2021 ◽  
Vol 9 (12) ◽  
pp. 2508
Author(s):  
Eirini-Evangelia Thomloudi ◽  
Polina C. Tsalgatidou ◽  
Eirini Baira ◽  
Konstantinos Papadimitriou ◽  
Anastasia Venieraki ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Gene Clusters ◽  
Gray Mold ◽  
Antagonistic Activity ◽  
Future Research ◽  
Single Culture ◽  
Plant Growth Promoting ◽  
Growth Promoting

The endophytic bacterial strain Hil4 was isolated from leaves of the medicinal plant Hypericum hircinum. It exhibited antifungal activity against Botrytis cinerea and a plethora of plant growth promoting traits in vitro. Whole genome sequencing revealed that it belongs to Bacillus halotolerans and possesses numerous secondary metabolite biosynthetic gene clusters and genes involved in plant growth promotion, colonization, and plant defense elicitation. The Mojavensin cluster was present in the genome, making this strain novel among plant-associated B. halotolerans strains. Extracts of secreted agar-diffusible compounds from single culture secretome extracts and dual cultures with B. cinerea were bioactive and had the same antifungal pattern on TLC plates after bioautography. UHPLC-HRMS analysis of the single culture secretome extract putatively annotated the consecutively produced antimicrobial substances and ISR elicitors. The isolate also proved efficient in minimizing the severity of gray mold post-harvest disease on table grape berries, as well as cherry tomatoes. Finally, it positively influenced the growth of Arabidopsis thaliana Col-0 and Solanum lycopersicum var. Chondrokatsari Messinias after seed biopriming in vitro. Overall, these results indicate that the B. halotolerans strain Hil4 is a promising novel plant growth promoting and biocontrol agent, and can be used in future research for the development of biostimulants and/or biological control agents.

scholarly journals Efficacy of Plant Growth-Promoting Bacteria Bacillus cereus YN917 for Biocontrol of Rice Blast

2021 ◽  
Vol 12 ◽  
Author(s):  
Hu Zhou ◽  
Zuo-hua Ren ◽  
Xue Zu ◽  
Xi-yue Yu ◽  
Hua-jun Zhu ◽  
...  
Keyword(s):  
Disease Prevention ◽  
Plant Growth ◽  
Bacillus Cereus ◽  
Rice Blast ◽  
Growth Promotion ◽  
Gene Clusters ◽  
Plant Growth Promoting Bacteria ◽  
Detached Leaf ◽  
Plant Growth Promoting ◽  
Growth Promoting

Bacillus cereus YN917, obtained from a rice leaf with remarkable antifungal activity against Magnaporthe oryzae, was reported in our previous study. The present study deciphered the possible biocontrol properties. YN917 strain exhibits multiple plant growth-promoting and disease prevention traits, including production of indole-3-acetic acid (IAA), ACC deaminase, siderophores, protease, amylase, cellulase, and β-1,3-glucanase, and harboring mineral phosphate decomposition activity. The effects of the strain YN917 on growth promotion and disease prevention were further evaluated under detached leaf and greenhouse conditions. The results revealed that B. cereus YN917 can promote seed germination and seedling plant growth. The growth status of rice plants was measured from the aspects of rice plumule, radicle lengths, plant height, stem width, root lengths, fresh weights, dry weights, and root activity when YN917 was used as inoculants. YN917 significantly reduced rice blast severity under detached leaf and greenhouse conditions. Genome analysis revealed the presence of gene clusters for biosynthesis of plant promotion and antifungal compounds, such as IAA, tryptophan, siderophores, and phenazine. In summary, YN917 can not only be used as biocontrol agents to minimize the use of chemical substances in rice blast control, but also can be developed as bio-fertilizers to promote the rice plant growth.

scholarly journals Genomic Mining and Physiological Characterization of new Halophilic Plant Growth Promoting Bacilli

2021 ◽  
Author(s):  
Claudia Petrillo ◽  
Stefany Castaldi ◽  
Mariamichela Lanzilli ◽  
Matteo Selci ◽  
Angelina Cordone ◽  
...  
Keyword(s):  
Plant Growth ◽  
Crop Production ◽  
Growth Promotion ◽  
Biological Activities ◽  
Gene Clusters ◽  
Plant Growth Promoting Bacteria ◽  
Dual Culture ◽  
Whole Genome Analysis ◽  
Plant Growth Promoting ◽  
Growth Promoting

Massive application of chemical fertilizers and pesticides has been the main strategy used to cope with the rising crop demands in the last decades. The indiscriminate use of chemicals while providing a temporary solution has led to a decrease in crop productivity and an increase in the environmental impact of modern agriculture. A sustainable alternative to the use of chemicals for crop production is the use of microorganisms naturally capable of enhancing plant growth and protecting crops from pests, known as Plant-Growth-Promoting Bacteria (PGPB). The aim of the present study was to isolate and characterize PGPB from salt-pans sand samples able to ameliorate plant fitness. To survive high salinity, salt-tolerant microbes produce a broad range of compounds with heterogeneous biological activities that are potentially beneficial for plant growth. We have isolated and screened in vitro a total of 20 halophilic spore-forming bacteria for phyto-beneficial traits and compared the results with two rhizosphere Bacilli recently isolated from the rhizosphere of the same collection site and recently characterized as potential biocontrol agents. Whole-genome analysis on five selected halophilic strains confirmed the presence of numerous gene clusters with PGP and biocontrol functions and of novel secondary-metabolite biosynthetic genes potentially involved in plant growth promotion and protection. The predicted biocontrol potential was confirmed in dual culture assays against several phytopathogenic fungi and bacteria. Interestingly, the absence of predicted gene clusters with known biocontrol functions in some of the isolates was not predictive of the in vivo results, supporting the need of combining laboratory assays and genome mining in PGPB identification for future applications.

scholarly journals Plant growth promoting endophyte Burkholderia contaminans NZ antagonizes phytopathogen Macrophomina phaseolina through melanin synthesis and pyrrolnitrin inhibition

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257863
Author(s):  
Nazia R. Zaman ◽  
Umar F. Chowdhury ◽  
Rifath N. Reza ◽  
Farhana T. Chowdhury ◽  
Mrinmoy Sarker ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Genome Mining ◽  
Gene Clusters ◽  
Macrophomina Phaseolina ◽  
Melanin Synthesis ◽  
Burkholderia Contaminans ◽  
Plant Growth Promoting ◽  
Growth Promoting

The endophytic bacterium Burkholderia contaminans NZ was isolated from jute, which is an important fiber-producing plant. This bacterium exhibits significant growth promotion activity in in vivo pot experiments, and like other plant growth-promoting (PGP) bacteria fixes nitrogen, produces indole acetic acid (IAA), siderophore, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. B. contaminans NZ is considered to exert a promising growth inhibitory effect on Macrophomina phaseolina, a phytopathogen responsible for infecting hundreds of crops worldwide. This study aimed to identify the possibility of B. contaminans NZ as a safe biocontrol agent and assess its effectiveness in suppressing phytopathogenic fungi, especially M. phaseolina. Co-culture of M. phaseolina with B. contaminans NZ on both solid and liquid media revealed appreciable growth suppression of M. phaseolina and its chromogenic aberration in liquid culture. Genome mining of B. contaminans NZ using NaPDoS and antiSMASH revealed gene clusters that displayed 100% similarity for cytotoxic and antifungal substances, such as pyrrolnitrin. GC-MS analysis of B. contaminans NZ culture extracts revealed various bioactive compounds, including catechol; 9,10-dihydro-12’-hydroxy-2’-methyl-5’-(phenylmethyl)- ergotaman 3’,6’,18-trione; 2,3-dihydro-3,5- dihydroxy-6-methyl-4H-pyran-4-one; 1-(1,6-Dioxooctadecyl)- pyrrolidine; 9-Octadecenamide; and 2- methoxy- phenol. These compounds reportedly exhibit tyrosinase inhibitory, antifungal, and antibiotic activities. Using a more targeted approach, an RP-HPLC purified fraction was analyzed by LC-MS, confirming the existence of pyrrolnitrin in the B. contaminans NZ extract. Secondary metabolites, such as catechol and ergotaman, have been predicted to inhibit melanin synthesis in M. phaseolina. Thus, B. contaminans NZ appears to inhibit phytopathogens by apparently impairing melanin synthesis and other potential biochemical pathways, exhibiting considerable fungistatic activity.

Enhancement of verticillium wilt resistance in tomato transplants by in vitro co-culture of seedlings with a plant growth promoting rhizobacterium (Pseudomonas sp. strain PsJN)

1998 ◽  
Vol 44 (6) ◽  
pp. 528-536 ◽  
Author(s):  
V K Sharma ◽  
J Nowak
Keyword(s):  
Plant Growth ◽  
Verticillium Wilt ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Disease Suppression ◽  
Pseudomonas Sp ◽  
Plant Growth Promoting ◽  
Growth Promoting

The potential utilization of a plant growth promoting rhizobacterium, Pseudomonas sp. strain PsJN, to enhance the resistance of tomato transplants to verticillium wilt was investigated. Plant growth and disease development were tested on the disease-susceptible cultivar Bonny Best after Verticillium dahliae infection of tissue culture plantlets bacterized in vitro (by co-culturing with the bacterium) and seedlings bacterized in vivo (after 3 weeks growth in the greenhouse). Significant differences in both disease suppression and plant growth were obtained between in vitro bacterized and nonbacterized (control) plants. The degree of protection afforded by in vitro bacterization depended on the inoculum density of V. dahliae; the best and worst protection occurred at the lowest (103 conidia ·mL-1) and highest (106 conidia ·mL-1) levels, respectively. In contrast, the in vivo bacterized tomatoes did not show plant growth promotion when compared to the nonbacterized control plants. When challenged with Verticillium, significant growth differences between in vivo bacterized plants (26.8% for shoot height) and nonbacterized controls were only seen at the 3rd week after inoculation. Compared with the in vitro inoculation, there was no delay in the verticillium wilt symptom expression, even at the lowest concentration of V. dahliae, by in vivo PsJN inoculation. These results suggest that endophytic colonization of tomato tissues is required for the Verticillium-resistance responses. Plant growth promotion preceeds the disease-resistance responses and may depend on the colonization thresholds and subsequent sensitization of hosts.Key words: Pseudomonas sp., plant growth promoting rhizobacterium, Verticillium dahliae, tomato, colonization, plant growth promotion, disease suppression.

scholarly journals Bacteria Isolated from Wastewater Irrigated Agricultural Soils Adapt to Heavy Metal Toxicity While Maintaining Their Plant Growth Promoting Traits

2021 ◽  
Vol 13 (14) ◽  
pp. 7792
Author(s):  
Abdul Wahab Ajmal ◽  
Saleha Saroosh ◽  
Shah Mulk ◽  
Muhammad Nadeem Hassan ◽  
Humaira Yasmin ◽  
...  
Keyword(s):  
Plant Growth ◽  
Agricultural Soils ◽  
Culture Media ◽  
Growth Promotion ◽  
Metal Resistance ◽  
Rrna Gene ◽  
Gene Sequence Analysis ◽  
Plant Growth Promoting ◽  
Growth Promoting

The present study explored the plant growth promotion and bioremediation potential of bacteria inhabiting wastewater irrigated agricultural soils. Thirty out of 75 bacterial isolates (40%), 29/75 (39%) and 28/75 (37%) solubilized Zn, K and PO4 during plate essays respectively. Fifty-six percent of the isolates produced siderophores, while 30% released protease in vitro. Seventy-four percent of bacteria resisted Pb, Ni and Cd at various concentrations added to the culture media plates. Sixteen out of 75 (26%) isolates were able to fix N in Nbf medium. Among these 16 N fixers, N fixing nifH, nifD and nifK genes was detected through PCR in 8, 7 and 1 strain respectively using gene specific primers designed in the study with Enterobacter sp. having all three (nifHKD) genes. Isolated bacteria showed resemblance to diverse genera such as Bacillus, Pseudomonas, Enterobacter, Citrobacter, Acinetobacter, Serratia, Klebsiella and Enterococcus based on 16S rRNA gene sequence analysis. In addition to showing the best mineral solubilization and metal resistance potential, Citrobacter sp. and Enterobacter sp. also removed 87%, 79% and 43% and 86%, 78% and 51% of Ni, Cd and Pb, respectively, from aqueous solution. These potent bacteria may be exploited both for bioremediation and biofertilization of wastewater irrigated soils leading to sustainable agriculture.

scholarly journals Endophytic Burkholderia sp. SSG as a potential biofertilizer promoting boxwood growth

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9547
Author(s):  
Ping Kong ◽  
Chuanxue Hong
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Plant Protection ◽  
Growth Promotion ◽  
Agar Plate ◽  
Gene Clusters ◽  
Plant Weight ◽  
Pgp Traits ◽  
Plant Growth Promoting ◽  
Growth Promoting

Background Burkholderia sp. SSG is a bacterial endophyte isolated from boxwood leaves showing a resistant response to infection by the boxwood blight pathogen Calonectria pseudonaviculata. SSG acted as a protective and curative biocontrol agent for boxwood blight and as a bio-sanitizer of disease inoculum in the field. Many gene clusters involved in antibiotic production and plant growth promotion (PGP) were found in the genome, giving this endophyte great application potential as a treatment for plant protection. However, the PGP features have not been documented. This study investigated the plant growth promotion activity of SSG in boxwood. Methods To determine whether SSG is a plant growth promoting bacterium, four PGP traits, auxin and siderophore production, nitrogen fixation and phosphate solubilization, were examined in the laboratory with colorimetric or agar plate assays. The plant growth promoting activity of SSG was tested on three boxwood varieties characterized by slow, intermediate and fast growth rates, namely Justin Brouwers, Buddy and Winter Gem, respectively. These plants were drenched with an SSG cell suspension or water and washed plant weight was compared before and after treatment to determine growth changes after 10 months. Results The SSG culture was sustainable on nitrogen free media, suggesting that SSG may fix atmospheric nitrogen. It was also a strong phosphate solubilizer and a potent siderophore and indole-3-acetic acid (IAA) producer. Significant growth promotion was observed on boxwood cultivars Justin Brouwers, Buddy and Winter Gem 10 months after plant roots were drenched with SSG cells. The growth rate of treated plants was 76.1, 58.3, and 37.3% higher than that of the control, respectively. The degree of growth promotion was significantly different among plant varieties, notably more pronounced with the slow and intermediate growers. This study demonstrates that the SSG bacterium has multiple PGP traits and is a prospective plant biofertilizer.

scholarly journals Genome sequencing and assessment of plant growth-promoting properties of a Serratia marcescens strain isolated from vermicompost

2018 ◽  
Author(s):  
Filipe P. Matteoli ◽  
Hemanoel Passarelli-Araujo ◽  
Régis Josué A. Reis ◽  
Letícia O. da Rocha ◽  
Emanuel M. de Souza ◽  
...  
Keyword(s):  
Plant Growth ◽  
Serratia Marcescens ◽  
Genome Sequencing ◽  
Growth Promotion ◽  
Antibiotic Production ◽  
Indole Compounds ◽  
Wide Range ◽  
Plant Growth Promoting ◽  
Growth Promoting

ABSTRACTPlant-bacteria associations have been extensively studied for their potential in increasing crop productivity in a sustainable manner. Serratia marcescens is a Gram-negative species found in a wide range of environments, including soil. Here we describe the genome sequencing and assessment of plant-growth promoting abilities of S. marcescens UENF-22GI (SMU), a strain isolated from mature cattle manure vermicompost. In vitro, SMU is able to solubilize P and Zn, to produce indole compounds (likely IAA), to colonize hyphae and counter the growth of two phytopathogenic fungi. Inoculation of maize with SMU remarkably increased seedling growth and biomass under greenhouse conditions. The SMU genome has 5 Mb, assembled in 17 scaffolds comprising 4,662 genes (4,528 are protein-coding). No plasmids were identified. SMU is phylogenetically placed within a clade comprised almost exclusively of environmental strains. We were able to find the genes and operons that are likely responsible for all the interesting plant-growth promoting features that were experimentally described. Genes involved other interesting properties that were not experimentally tested (e.g. tolerance against metal contamination) were also identified. The SMU genome harbors a horizontally-transferred genomic island involved in antibiotic production, antibiotic resistance, and anti-phage defense via a novel ADP-ribosyltransferase-like protein and possible modification of DNA by a deazapurine base, which likely contributes to the SMU competitiveness against other bacteria. Collectively, our results suggest that S. marcescens UENF-22GI is a strong candidate to be used in the enrichment of substrates for plant growth promotion or as part of bioinoculants for Agriculture.

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