scholarly journals Enhanced Control of Plant Wilt Disease by a Xylose-Inducible degQ Gene Engineered into Bacillus velezensis Strain SQR9XYQ

2019 ◽  
Vol 109 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Zhihui Xu ◽  
Jiyu Xie ◽  
Huihui Zhang ◽  
Dandan Wang ◽  
Qirong Shen ◽  
...  
Keyword(s):  
Plant Growth ◽  
Biofilm Formation ◽  
Antibiotic Production ◽  
Genetically Engineered ◽  
Flagellar Motility ◽  
Bacillus Velezensis ◽  
Tomato Root ◽  
Bacillus Spp ◽  
Plant Growth Promoting

Bacillus velezensis SQR9 (former B. amyloliquefaciens SQR9) is a plant-growth-promoting rhizobacterium (PGPR) that promotes plant growth and health. The colonization of PGPR strains along plant roots is a prerequisite for them to execute their specific functions. However, one problem of microbial introduction in practice is that the applied PGPR strains do not always successfully colonize the rhizosphere. In Bacillus spp., two-component signal transduction system (TCS) DegS/U regulates flagellar motility, biofilm formation and antibiotic production. Phosphorylation of DegU by DegS is positively affected by DegQ protein. In this study, we constructed a xylose-inducible degQ genetically engineered strain SQR9XYQ to improve the biocontrol activity. The results from in vitro, root in situ, greenhouse experiments and RT-qPCR studies demonstrate that (i) the phosphorylation of DegU in SQR9XYQ can be gradually activated by xylose, which is a component of both cucumber and tomato root exudates, and (ii) biofilm formation, antibiotic expression, colonization activity, and biocontrol efficiency were improved in SQR9XYQ compared with the wild-type strain SQR9. These results suggest that colonization trait is important to biocontrol strains for maintenance of plant health.

scholarly journals A prospectus of plant growth promoting endophytic bacterium from orchid (Vanda cristata)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sujit Shah ◽  
Krishna Chand ◽  
Bhagwan Rekadwad ◽  
Yogesh S. Shouche ◽  
Jyotsna Sharma ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Colonization ◽  
Endophytic Bacterium ◽  
Epifluorescence Microscopy ◽  
In Vitro Cultivation ◽  
Rrna Gene ◽  
Bacillus Spp ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Background A plant growth-promoting endophytic bacterium PVL1 isolated from the leaf of Vanda cristata has the ability to colonize with roots of plants and protect the plant. PVL1 was isolated using laboratory synthetic media. 16S rRNA gene sequencing method has been employed for identification before and after root colonization ability. Results Original isolated and remunerated strain from colonized roots were identified as Bacillus spp. as per EzBiocloud database. The presence of bacteria in the root section of the plantlet was confirmed through Epifluorescence microscopy of colonized roots. The in-vitro plantlet colonized by PVL1 as well as DLMB attained higher growth than the control. PVL1 capable of producing plant beneficial phytohormone under in vitro cultivation. HPLC and GC-MS analysis suggest that colonized plants contain Indole Acetic Acid (IAA). The methanol extract of Bacillus spp., contains 0.015 μg in 1 μl concentration of IAA. PVL1 has the ability to produce antimicrobial compounds such as ethyl iso-allocholate, which exhibits immune restoring property. One-way ANOVA shows that results were statistically significant at P ≤ 0.05 level. Conclusions Hence, it has been concluded that Bacillus spp. PVL1 can promote plant growth through secretion of IAA during root colonization and ethyl iso-allocholate to protect plants from foreign infections. Thus, this study supports to support Koch’s postulates of bacteria establishment.

scholarly journals Bacillus velezensisWall Teichoic Acids Are Required for Biofilm Formation and Root Colonization

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Zhihui Xu ◽  
Huihui Zhang ◽  
Xinli Sun ◽  
Yan Liu ◽  
Wuxia Yan ◽  
...  
Keyword(s):  
Plant Growth ◽  
Biofilm Formation ◽  
Root Colonization ◽  
Molecular Networks ◽  
Model Organisms ◽  
Bacillus Velezensis ◽  
Content Type ◽  
Plant Growth Promoting ◽  
Colonization Process ◽  
Growth Promoting

ABSTRACTRhizosphere colonization by plant growth-promoting rhizobacteria (PGPR) along plant roots facilitates the ability of PGPR to promote plant growth and health. Thus, an understanding of the molecular mechanisms of the root colonization process by plant-beneficialBacillusstrains is essential for the use of these strains in agriculture. Here, we observed that ansfpgene mutant of the plant growth-promoting rhizobacteriumBacillus velezensisSQR9 was unable to form normal biofilm architecture, and differential protein expression was observed by proteomic analysis. A minor wall teichoic acid (WTA) biosynthetic protein, GgaA, was decreased over 4-fold in the Δsfpmutant, and impairment of theggaAgene postponed biofilm formation and decreased cucumber root colonization capabilities. In addition, we provide evidence that the major WTA biosynthetic enzyme GtaB is involved in both biofilm formation and root colonization. The deficiency in biofilm formation of the ΔgtaBmutant may be due to an absence of UDP-glucose, which is necessary for the synthesis of biofilm matrix exopolysaccharides (EPS). These observations provide insights into the root colonization process by a plant-beneficialBacillusstrain, which will help improve its application as a biofertilizer.IMPORTANCEBacillus velezensisis a Gram-positive plant-beneficial bacterium which is widely used in agriculture. Additionally,Bacillusspp. are some of the model organisms used in the study of biofilms, and as such, the molecular networks and regulation systems of biofilm formation are well characterized. However, the molecular processes involved in root colonization by plant-beneficialBacillusstrains remain largely unknown. Here, we showed that WTAs play important roles in the plant root colonization process. The loss of thegtaBgene affects the ability ofB. velezensisSQR9 to sense plant polysaccharides, which are important environmental cues that trigger biofilm formation and colonization in the rhizosphere. This knowledge provides new insights into theBacillusroot colonization process and can help improve our understanding of plant-rhizobacterium interactions.

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.

scholarly journals From Strain Characterization to Field Authorization: Highlights on Bacillus velezensis Strain B25 Beneficial Properties for Plants and Its Activities on Phytopathogenic Fungi

2021 ◽  
Vol 9 (9) ◽  
pp. 1924
Author(s):  
Pierre Joly ◽  
Alexandra Calteau ◽  
Aurélie Wauquier ◽  
Rémi Dumas ◽  
Mylène Beuvin ◽  
...  
Keyword(s):  
Plant Growth ◽  
Crop Yields ◽  
Antibiotic Resistance Genes ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
In Planta ◽  
Bacillus Velezensis ◽  
Plant Growth Promoting ◽  
Growth Promoting

Agriculture is in need of alternative products to conventional phytopharmaceutical treatments from chemical industry. One solution is the use of natural microorganisms with beneficial properties to ensure crop yields and plant health. In the present study, we focused our analyses on a bacterium referred as strain B25 and belonging to the species Bacillus velezensis (synonym B. amyloliquefaciens subsp. plantarum or B. methylotrophicus), a promising plant growth promoting rhizobacterium (PGPR) and an inhibitor of pathogenic fungi inducing crops diseases. B25 strain activities were investigated. Its genes are well preserved, with their majority being common with other Bacillus spp. strains and responsible for the biosynthesis of secondary metabolites known to be involved in biocontrol and plant growth-promoting activities. No antibiotic resistance genes were found in the B25 strain plasmid. In vitro and in planta tests were conducted to confirm these PGPR and biocontrol properties, showing its efficiency against 13 different pathogenic fungi through antibiosis mechanism. B25 strain also showed good capacities to quickly colonize its environment, to solubilize phosphorus and to produce siderophores and little amounts of auxin-type phytohormones (around 13,051 µg/mL after 32 h). All these findings combined to the fact that B25 demonstrated good properties for industrialization of the production and an environmental-friendly profile, led to its commercialization under market authorization since 2018 in several biostimulant preparations and opened its potential use as a biocontrol agent.

scholarly journals Coastal Ecosystems as Sources of Biofertilizers in Agriculture: From Genomics to Application in an Urban Orchard

2021 ◽  
Vol 8 ◽  
Author(s):  
Eloísa Pajuelo ◽  
Sandra Arjona ◽  
Ignacio D. Rodríguez-Llorente ◽  
Enrique Mateos-Naranjo ◽  
Susana Redondo-Gómez ◽  
...  
Keyword(s):  
Plant Growth ◽  
Bacterial Consortium ◽  
Metal Resistance ◽  
Growth And Yield ◽  
Flagellar Motility ◽  
Pilot Experiment ◽  
Metabolic Versatility ◽  
Plant Growth Promoting ◽  
Growth Promoting

Pantoea agglomerans RSO7, a rhizobacterium previously isolated from Spartina maritima grown on metal polluted saltmarshes, had demonstrated good plant growth promoting activity for its host halophyte, but was never tested in crops. The aims of this study were: (1) testing PGP activity on a model plant (alfalfa) in vitro; (2) testing a bacterial consortium including RSO7 as biofertilizer in a pilot experiment in urban orchard; and (3) identifying the traits related to PGP activities. RSO7 was able to enhance alfalfa growth in vitro, particularly the root system, besides improving plant survival and protecting plants against fungal contamination. In addition, in a pilot experiment in urban orchard, a consortium of three bacteria including RSO7 was able to foster the growth and yield of several winter crops between 1.5 and 10 fold, depending on species. Moreover, the analysis of chlorophyll fluorescence revealed that photosynthesis was highly ameliorated. Genome analysis of RSO7 depicted the robustness of this bacterial strain which showed resilience to multiple stresses (heat, cold, UV radiation, several xenobiotics). Together with wide metabolic versatility, genes conferring resistance to oxidative stress were identified. Many genes involved in metal resistance (As, Cu, Ni, Co, Zn, Se, Te) and in tolerance toward high osmolality (production of a battery of osmoprotectans) were also found. Regarding plant growth promoting properties, traits for phosphate solubilization, synthesis of a battery of siderophores and production of IAA were detected. In addition, the bacterium has genes related to key processes in the rhizosphere including flagellar motility, chemotaxis, quorum sensing, biofilm formation, plant-bacteria dialog, and high competitiveness in the rhizosphere. Our results suggest the high potential of this bacterium as bioinoculant for an array of crops. However, the classification in biosecurity group 2 prevents its use according to current European regulation. Alternative formulations for the application of the bioinoculant are discussed.

scholarly journals Genomic Insights Into the Antifungal Activity and Plant Growth-Promoting Ability in Bacillus velezensis CMRP 4490

2021 ◽  
Vol 11 ◽  
Author(s):  
Gustavo Manoel Teixeira ◽  
Mirela Mosela ◽  
Maria Luiza Abreu Nicoletto ◽  
Renan Augusto Ribeiro ◽  
Mariangela Hungria ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Plant Growth ◽  
Dna Sequences ◽  
Bacterial Genome ◽  
Coating Film ◽  
Bacillus Velezensis ◽  
Significant Difference ◽  
Plant Growth Promoting ◽  
Growth Promoting

The main objective of this study was to evaluate Bacillus velezensis strain CMRP 4490 regarding its ability to inhibit soil-borne plant pathogens and to increase plant growth. The study included evaluation of in vitro antifungal control, sequencing the bacterial genome, mining genes responsible for the synthesis of secondary metabolites, root colonization ability, and greenhouse studies for the assessment of plant growth–promoting ability. The strain was obtained from soil samples in the north of Paraná in Brazil and was classified as a B. velezensis, which is considered a promising biological control agent. In vitro assay showed that B. velezensis CMRP 4490 presented antagonistic activity against Sclerotinia sclerotiorum, Macrophomina phaseolina, Botrytis cinerea, and Rhizoctonia solani with a mycelial growth inhibition of approximately 60%, without any significant difference among them. To well understand this strain and to validate its effect on growth-promoting rhizobacteria, it was decided to explore its genetic content through genome sequencing, in vitro, and greenhouse studies. The genome of CMRP 4490 was estimated at 3,996,396 bp with a GC content of 46.4% and presents 4,042 coding DNA sequences. Biosynthetic gene clusters related to the synthesis of molecules with antifungal activity were found in the genome. Genes linked to the regulation/formation of biofilms, motility, and important properties for rhizospheric colonization were also found in the genome. Application of CMRP 4490 as a coating film on soybean increased from 55.5 to 64% on germination rates when compared to the control; no differences were observed among treatments for the maize germination. The results indicated that B. velezensis CMRP 4490 could be a potential biocontrol agent with plant growth–promoting ability.

scholarly journals Two Lysine Sites That Can Be Malonylated Are Important for LuxS Regulatory Roles in Bacillus velezensis

2021 ◽  
Vol 9 (6) ◽  
pp. 1338
Author(s):  
Xianming Cao ◽  
Yulong Li ◽  
Jialu Fan ◽  
Yinjuan Zhao ◽  
Rainer Borriss ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Biological Function ◽  
Antibiotic Production ◽  
Post Translational Modification ◽  
Inhibitory Effects ◽  
Regulatory Circuit ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
High Level

S-ribosylhomocysteine lyase (LuxS) has been shown to regulate bacterial multicellular behaviors, typically biofilm formation. However, the mechanisms for the regulation are still mysterious. We previously identified a malonylation modification on K124 and K130 of the LuxS in the plant growth-promoting rhizobacterium B. velezensis (FZB42). In this work, we investigated the effects of the two malonylation sites on biofilm formation and other biological characteristics of FZB42. The results showed that the K124R mutation could severely impair biofilm formation, swarming, and sporulation but promote AI-2 production, suggesting inhibitory effects of high-level AI-2 on the features. All mutations (K124R, K124E, K130R, and K130E) suppressed FZB42 sporulation but increased its antibiotic production. The double mutations generally had a synergistic effect or at least equal to the effects of the single mutations. The mutation of K130 but not of K124 decreased the in vitro enzymatic activity of LuxS, corresponding to the conservation of K130 among various Bacillus LuxS proteins. From the results, we deduce that an alternative regulatory circuit may exist to compensate for the roles of LuxS upon its disruption. This study broadens the understanding of the biological function of LuxS in bacilli and underlines the importance of the two post-translational modification sites.

scholarly journals Multi-Trait Wheat Rhizobacteria from Calcareous Soil with Biocontrol Activity Promote Plant Growth and Mitigate Salinity Stress

2021 ◽  
Vol 9 (8) ◽  
pp. 1588
Author(s):  
Anastasia Venieraki ◽  
Styliani N. Chorianopoulou ◽  
Panagiotis Katinakis ◽  
Dimitris L. Bouranis
Keyword(s):  
Plant Growth ◽  
Salinity Stress ◽  
Calcareous Soil ◽  
In Vitro Studies ◽  
Pgp Traits ◽  
Biocontrol Activity ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Microbial Fertilizers

Plant growth promoting rhizobacteria (PGPR) can be functional microbial fertilizers and/or biological control agents, contributing to an eco-spirit and safe solution for chemical replacement. Therefore, we have isolated rhizospheric arylsulfatase (ARS)-producing bacteria, belonging to Pseudomonas and Bacillus genus, from durum wheat crop grown on calcareous soil. These isolates harbouring plant growth promoting (PGP) traits were further evaluated in vitro for additional PGP traits, including indole compounds production and biocontrol activity against phytopathogens, limiting the group of multi-trait strains to eight. The selected bacterial strains were further evaluated for PGP attributes associated with biofilm formation, compatibility, salt tolerance ability and effect on plant growth. In vitro studies demonstrated that the multi-trait isolates, Bacillus (1.SG.7, 5.SG.3) and Pseudomonas (2.SG.20, 2.C.19) strains, enhanced the lateral roots abundance and shoots biomass, mitigated salinity stress, suggesting the utility of beneficial ARS-producing bacteria as potential microbial fertilizers. Furthermore, in vitro studies demonstrated that compatible combinations of multi-trait isolates, Bacillus sp. 1.SG.7 in a mixture coupled with 5.SG.3, and 2.C.19 with 5.SG.3 belonging to Bacillus and Pseudomonas, respectively, may enhance plant growth as compared to single inoculants.

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