scholarly journals Bacterial Formulations in Induction of Resistance and Growth Promotion of Tomato Plants

2018 ◽  
Vol 10 (10) ◽  
pp. 493
Author(s):  
José R. M. Campos Neto ◽  
Rafael Ribeiro Chaves ◽  
Diogo Herison Silva Sardinha ◽  
Luiz Gustavo de Lima Melo ◽  
Antônia Alice Costa Rodrigues

The objective of this work was to evaluate the effectiveness of seed treatment with fresh suspensions and powder formulations with Bacillus methylotrophicus to promote plant growth and induction of resistance against fusarium wilt (Fusarium oxysporum f. sp. lycopersici) in tomato plants under greenhouse conditions, verifying the occurrence of morphological and biochemical changes in the evaluated plants. Powder formulations based on Cassava (Manihot esculenta), Arrowroot (Maranta arundinacea) and sodium alginate containing Bacillus, in addition to the commercial product Quartz®, were used to microbiolize the tomato seeds of the cultivar Santa Cruz. The formulations promoted plant growth, with a seedling vigor index greater than 50% for all treatments containing B. mthylotrophicus, in addition to a significant increase in total dry matter. The treatments induced systemic resistance, controlling the fusarium wilt with a 75% reduction of the disease and activation of enzymes such as peroxidase and polyphenoloxidase, only β-1,3-glucanase presented less activity than controls (treatments without B. mthylotrophicus). Thus, the use of formulations containing Bacillus are efficient in promoting plant growth of tomato plants and in inducing resistance to the control of fusarium wilt.

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 137
Author(s):  
Maedeh Kamali ◽  
Dianjing Guo ◽  
Shahram Naeimi ◽  
Jafar Ahmadi

Tomato Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici (Fol), is a destructive disease that threatens the agricultural production of tomatoes. In the present study, the biocontrol potential of strain KR2-7 against Fol was investigated through integrated genome mining and chemical analysis. Strain KR2-7 was identified as B. inaquosorum based on phylogenetic analysis. Through the genome mining of strain KR2-7, we identified nine antifungal and antibacterial compound biosynthetic gene clusters (BGCs) including fengycin, surfactin and Bacillomycin F, bacillaene, macrolactin, sporulation killing factor (skf), subtilosin A, bacilysin, and bacillibactin. The corresponding compounds were confirmed through MALDI-TOF-MS chemical analysis. The gene/gene clusters involved in plant colonization, plant growth promotion, and induced systemic resistance were also identified in the KR2-7 genome, and their related secondary metabolites were detected. In light of these results, the biocontrol potential of strain KR2-7 against tomato Fusarium wilt was identified. This study highlights the potential to use strain KR2-7 as a plant-growth promotion agent.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 579
Author(s):  
Carmen Sanjuana Delgado-Ramírez ◽  
Rufina Hernández-Martínez ◽  
Edgardo Sepúlveda

Plant growth-promoting rhizobacteria are often utilized to improve crop health and productivity. Nevertheless, their positive effects can be hindered if they fail to withstand the environmental and ecological conditions of the regions where they are applied. An alternative approach to circumvent this problem is a tailored selection of bacteria for specific agricultural systems. In this work, we evaluated the plant growth promoting and pathogen inhibition activity of rhizobacteria obtained from the rhizosphere of Mariola (Solanum hindsianum), an endemic shrub from Baja California. Eight strains were capable of inhibiting Fusarium oxysporum in vitro, and thirteen strains were found to possess three or more plant-growth-promotion traits. Molecular identification of these strains, using 16 s rRNA partial sequences, identified them as belonging to the genera Arthrobacter, Bacillus, Paenibacillus, Pseudomonas, and Streptomyces. Finally, the effect of selected plant growth-promoting rhizobacteria (PGPR) strains on the growth and suppression of Fusarium wilt in tomato was evaluated. Results showed that these strains improved tomato plants growth under greenhouse conditions and reduced Fusarium wilt effects, as reflected in several variables such as length and weight of roots and stem. This work highlights the potential of native plants related to regionally important crops as a valuable source of beneficial bacteria.


2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Manuella Nóbrega Dourado ◽  
Aline Aparecida Camargo Neves ◽  
Daiene Souza Santos ◽  
Welington Luiz Araújo

The genusMethylobacteriumis composed of pink-pigmented facultative methylotrophic (PPFM) bacteria, which are able to synthesize carotenoids and grow on reduced organic compounds containing one carbon (C1), such as methanol and methylamine. Due to their high phenotypic plasticity, these bacteria are able to colonize different habitats, such as soil, water, and sediment, and different host plants as both endophytes and epiphytes. In plant colonization, the frequency and distribution may be influenced by plant genotype or by interactions with other associated microorganisms, which may result in increasing plant fitness. In this review, different aspects of interactions with the host plant are discussed, including their capacity to fix nitrogen, nodule the host plant, produce cytokinins, auxin and enzymes involved in the induction of systemic resistance, such as pectinase and cellulase, and therefore plant growth promotion. In addition, bacteria belonging to this group can be used to reduce environmental contamination because they are able to degrade toxic compounds, tolerate high heavy metal concentrations, and increase plant tolerance to these compounds. Moreover, genome sequencing and omics approaches have revealed genes related to plant-bacteria interactions that may be important for developing strains able to promote plant growth and protection against phytopathogens.


2007 ◽  
Vol 53 (2) ◽  
pp. 159-167 ◽  
Author(s):  
J.W. Kloepper ◽  
A. Gutiérrez-Estrada ◽  
J.A. McInroy

For several years, we have noticed that plant growth-promoting rhizobacteria (PGPR), which consistently promote plant growth in greenhouse tests during spring, summer, and fall, fail to elicit plant growth promotion during the midwinter under ambient light conditions. This report tests the hypothesis that photoperiod regulates elicitation of growth promotion and induced systemic resistance (ISR) by PGPR. A commercially available formulation of PGPR strains Bacillus subtilis GB03 and Bacillus amyloliquefaciens IN937a (BioYield®) was used to grow tomato and pepper transplants under short-day (8 h of light) (SD) and long-day (12 h of light) (LD) conditions. Results of many experiments indicated that under LD conditions, BioYield consistently elicited significant increases in root and shoot mass as well as in several parameters of root architecture. However, under SD conditions, such increases were not elicited. Differential root colonization of plants grown under LD and SD conditions and changes in leachate quality partially account for these results. BioYield elicited ISR in tomato and pepper under both LD and SD conditions, indicating that although growth promotion was not elicited under SD conditions, induced resistance was. Overall, the results indicate that PGPR-mediated growth promotion is regulated by photoperiod, while ISR is not.


2021 ◽  
Vol 22 (9) ◽  
pp. 5049
Author(s):  
Muhammad Ayaz ◽  
Qurban Ali ◽  
Ayaz Farzand ◽  
Abdur Rashid Khan ◽  
Hongli Ling ◽  
...  

Bacillus volatiles to control plant nematodes is a topic of great interest among researchers due to its safe and environmentally friendly nature. Bacillus strain GBSC56 isolated from the Tibet region of China showed high nematicidal activity against M. incognita, with 90% mortality as compared with control in a partition plate experiment. Pure volatiles produced by GBSC56 were identified through gas chromatography and mass spectrometry (GC-MS). Among 10 volatile organic compounds (VOCs), 3 volatiles, i.e., dimethyl disulfide (DMDS), methyl isovalerate (MIV), and 2-undecanone (2-UD) showed strong nematicidal activity with a mortality rate of 87%, 83%, and 80%, respectively, against M. incognita. The VOCs induced severe oxidative stress in nematodes, which caused rapid death. Moreover, in the presence of volatiles, the activity of antioxidant enzymes, i.e., SOD, CAT, POD, and APX, was observed to be enhanced in M. incognita-infested roots, which might reduce the adverse effect of oxidative stress-induced after infection. Moreover, genes responsible for plant growth promotion SlCKX1, SlIAA1, and Exp18 showed an upsurge in expression, while AC01 was downregulated in infested plants. Furthermore, the defense-related genes (PR1, PR5, and SlLOX1) in infested tomato plants were upregulated after treatment with MIV and 2-UD. These findings suggest that GBSC56 possesses excellent biocontrol potential against M. incognita. Furthermore, the study provides new insight into the mechanism by which GBSC56 nematicidal volatiles regulate antioxidant enzymes, the key genes involved in plant growth promotion, and the defense mechanism M. incognita-infested tomato plants use to efficiently manage root-knot disease.


Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 682
Author(s):  
Bruno Henrique Silva Dias ◽  
Sung-Hee Jung ◽  
Juliana Velasco de Castro Oliveira ◽  
Choong-Min Ryu

Plant growth-promoting rhizobacteria (PGPR) associated with plant roots can trigger plant growth promotion and induced systemic resistance. Several bacterial determinants including cell-wall components and secreted compounds have been identified to date. Here, we review a group of low-molecular-weight volatile compounds released by PGPR, which improve plant health, mostly by protecting plants against pathogen attack under greenhouse and field conditions. We particularly focus on C4 bacterial volatile compounds (BVCs), such as 2,3-butanediol and acetoin, which have been shown to activate the plant immune response and to promote plant growth at the molecular level as well as in large-scale field applications. We also disc/ uss the potential applications, metabolic engineering, and large-scale fermentation of C4 BVCs. The C4 bacterial volatiles act as airborne signals and therefore represent a new type of biocontrol agent. Further advances in the encapsulation procedure, together with the development of standards and guidelines, will promote the application of C4 volatiles in the field.


2021 ◽  
pp. 104961
Author(s):  
Sravani Ankati ◽  
Vadlamudi Srinivas ◽  
Sambangi Pratyusha ◽  
Subramaniam Gopalakrishnan

2019 ◽  
Vol 95 (9) ◽  
Author(s):  
Namis Eltlbany ◽  
Mohamed Baklawa ◽  
Guo-Chun Ding ◽  
Dinah Nassal ◽  
Nino Weber ◽  
...  

ABSTRACT Soil microbial communities interact with roots, affecting plant growth and nutrient acquisition. In the present study, we aimed to decipher the effects of the inoculants Trichoderma harzianum T-22, Pseudomonas sp. DSMZ 13134, Bacillus amyloliquefaciens FZB42 or Pseudomonas sp. RU47 on the rhizosphere microbial community and their beneficial effects on tomato plants grown in moderately low phosphorous soil under greenhouse conditions. We analyzed the plant mass, inoculant colony forming units and rhizosphere communities on 15, 22, 29 and 43 days after sowing. Selective plating showed that the bacterial inoculants had a good rhizocompetence and accelerated shoot and root growth and nutrient accumulation. 16S rRNA gene fingerprints indicated changes in the rhizosphere bacterial community composition. Amplicon sequencing revealed that rhizosphere bacterial communities from plants treated with bacterial inoculants were more similar to each other and distinct from those of the control and the Trichoderma inoculated plants at harvest time, and numerous dynamic taxa were identified. In conclusion, likely both, inoculants and the rhizosphere microbiome shifts, stimulated early plant growth mainly by improved spatial acquisition of available nutrients via root growth promotion. At harvest, all tomato plants were P-deficient, suggesting a limited contribution of inoculants and the microbiome shifts to the solubilization of sparingly soluble soil P.


2016 ◽  
Vol 46 (2) ◽  
pp. 149-158 ◽  
Author(s):  
Ariana Alves Rodrigues ◽  
Marcus Vinicius Forzani ◽  
Renan de Souza Soares ◽  
Sergio Tadeu Sibov ◽  
José Daniel Gonçalves Vieira

ABSTRACT Microorganisms play a vital role in maintaining soil fertility and plant health. They can act as biofertilizers and increase the resistance to biotic and abiotic stress. This study aimed at isolating and characterizing plant growth-promoting bacteria associated with sugarcane, as well as assessing their ability to promote plant growth. Endophytic bacteria from leaf, stem, root and rhizosphere were isolated from the RB 867515 commercial sugarcane variety and screened for indole acetic acid (IAA) production, ability to solubilize phosphate, fix nitrogen and produce hydrogen cyanide (HCN), ammonia and the enzymes pectinase, cellulase and chitinase. A total of 136 bacteria were isolated, with 83 of them presenting some plant growth mechanism: 47 % phosphate solubilizers, 26 % nitrogen fixers and 57 % producing IAA, 0.7 % HCN and chitinase, 45 % ammonia, 30 % cellulose and 8 % pectinase. The seven best isolates were tested for their ability to promote plant growth in maize. The isolates tested for plant growth promotion belong to the Enterobacteriaceae family and the Klebsiella, Enterobacter and Pantoea genera. Five isolates promoted plant growth in greenhouse experiments, showing potential as biofertilizers.


2003 ◽  
Vol 49 (6) ◽  
pp. 383-389 ◽  
Author(s):  
Zhinong Yan ◽  
M S Reddy ◽  
Joseph W Kloepper

Plant-growth-promoting rhizobacteria (PGPR) are used on crops most often as seed treatments; however, an alternative application method for transplanted vegetables is mixing PGPR into the soilless medium in which the transplants are grown. Studies were undertaken to compare root colonization and persistence of rifampicin-resistant mutants of PGPR strains Bacillus pumilus SE34 and Pseudomonas fluorescens 89B61, SE34r and 89B61r, on tomato as a function of application method. When the bacteria were incorporated into Promix(tm) soilless medium at log 6, 7, and 8 colony- forming units/g, populations of strain SE34r per gram of medium maintained the initial inoculum densities, while populations of 89B61r decreased approximately one to two orders of magnitude by 4 weeks after planting. The populations of each PGPR strain colonizing roots after application into the soilless medium showed a similar pattern at 6 weeks as that at 4 weeks after planting, with higher populations on the whole roots and lateral roots than on the taproots. Strain SE34r but not 89B61r moved upwards and colonized the phyllosphere when incorporated into the soilless medium. Following application as seed treatment, populations of SE34r were significantly higher on upper roots and on the taproot than were populations following application through the soilless medium. Conversely, populations were higher on lower roots and lateral roots following application through the soilless medium than were populations following application as seed treatment. While strain SE34 enhanced plant growth with application both to the medium and as seed treatment, the level of growth promotion was significantly greater with application in the soilless medium. The results indicate that PGPR can be successfully incorporated into soilless media in vegetable transplant production systems.Key words: rhizobacteria, plant colonization, Bacillus pumilus, Pseudomonas fluorescens.


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