Growth Promotion and Disease Suppression Ability of a Streptomyces sp. CB-75 from Banana Rhizosphere Soil

Bacillus spp. produce a variety of compounds involved in the biocontrol of plant pathogens and promotion of plant growth, which makes them potential candidates for most agricultural and biotechnological applications. Bacilli exhibit antagonistic activity by excreting extracellular metabolites such as antibiotics, cell wall hydrolases, and siderophores. Additionally, Bacillus spp. improve plant response to pathogen attack by triggering induced systemic resistance (ISR). Besides being the most promising biocontrol agents, Bacillus spp. promote plant growth via nitrogen fixation, phosphate solubilization, and phytohormone production. Antagonistic and plant growth-promoting strains of Bacillus spp. might be useful in formulating new preparations. Numerous studies of a wide range of plant species revealed a steady increase in the number of Bacillus spp. identified as potential biocontrol agents and plant growth promoters. Among different mechanisms of action, it remains unclear which individual or combined traits could be used as predictors in the selection of the best strains for crop productivity improvement. Due to numerous factors that influence the successful application of Bacillus spp., it is necessary to understand how different strains function in biological control and plant growth promotion, and distinctly define the factors that contribute to their more efficient use in the field.

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The effect of salt-tolerant antagonistic bacteria from tomato rhizosphere on plant growth promotion and damping-off disease suppression under salt-stress conditions

Acta Agriculturae Scandinavica Section B - Soil & Plant Science ◽

10.1080/09064710.2019.1668956 ◽

2019 ◽

Vol 70 (1) ◽

pp. 69-75 ◽

Cited By ~ 1

Author(s):

Thamodini Gaya Karunasinghe ◽

Issa Hashil Al-Mahmooli ◽

Abdullah Mohammed Al-Sadi ◽

Rethinasamy Velazhahan

Keyword(s):

Salt Stress ◽

Plant Growth ◽

Plant Growth Promotion ◽

Growth Promotion ◽

Stress Conditions ◽

Disease Suppression ◽

Antagonistic Bacteria ◽

Damping Off ◽

Salt Tolerant

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Disruption of Firmicutes and Actinobacteria abundance in tomato rhizosphere causes the incidence of bacterial wilt disease

The ISME Journal ◽

10.1038/s41396-020-00785-x ◽

2020 ◽

Vol 15 (1) ◽

pp. 330-347 ◽

Cited By ~ 1

Author(s):

Sang-Moo Lee ◽

Hyun Gi Kong ◽

Geun Cheol Song ◽

Choong-Min Ryu

Keyword(s):

Bacterial Wilt ◽

Rhizosphere Soil ◽

Plant Protection ◽

Plant Immunity ◽

Disease Suppression ◽

Culturable Bacteria ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Individual Strain ◽

Bacillus Niacini

AbstractEnrichment of protective microbiota in the rhizosphere facilitates disease suppression. However, how the disruption of protective rhizobacteria affects disease suppression is largely unknown. Here, we analyzed the rhizosphere microbial community of a healthy and diseased tomato plant grown <30-cm apart in a greenhouse at three different locations in South Korea. The abundance of Gram-positive Actinobacteria and Firmicutes phyla was lower in diseased rhizosphere soil (DRS) than in healthy rhizosphere soil (HRS) without changes in the causative Ralstonia solanacearum population. Artificial disruption of Gram-positive bacteria in HRS using 500-μg/mL vancomycin increased bacterial wilt occurrence in tomato. To identify HRS-specific and plant-protective Gram-positive bacteria species, Brevibacterium frigoritolerans HRS1, Bacillus niacini HRS2, Solibacillus silvestris HRS3, and Bacillus luciferensis HRS4 were selected from among 326 heat-stable culturable bacteria isolates. These four strains did not directly antagonize R. solanacearum but activated plant immunity. A synthetic community comprising these four strains displayed greater immune activation against R. solanacearum and extended plant protection by 4 more days in comparison with each individual strain. Overall, our results demonstrate for the first time that dysbiosis of the protective Gram-positive bacterial community in DRS promotes the incidence of disease.

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