scholarly journals The use of Pseudomonas spp. as bacterial biocontrol agents to control plant disease

2021 ◽  
Author(s):  
Monica Höfte ◽  
Keyword(s):  
Antimicrobial Activity ◽  
Secondary Metabolites ◽  
Genome Mining ◽  
Control Plant ◽  
Biocontrol Agents ◽  
Systemic Resistance ◽  
Control Soil ◽  
Soil Pathogens ◽  
Plant Parts ◽  
The Third

Most Pseudomonas biocontrol strains are associated with the rhizosphere of plants, where they control soil pathogens by antibiosis or competition, and leaf pathogens via induced systemic resistance. Genome mining and the division of the vastly heterogeneous genus Pseudomonas in phylogenomic (sub)groups has clarified the relation between biocontrol characteristics and phylogeny. Based on their activity, Pseudomonas biocontrol strains come in three types. A first type, represented by P. chlororaphis, P. protegens, P. corrugata and P. aeruginosa (sub)group strains, produces an arsenal of secondary metabolites with broad antimicrobial activity. The second type is found in the P. putida, P. fluorescens, P. koreensis, P. mandelii, and P. gessardii (sub)group. The spectrum of biocontrol properties of these strains is less diverse and involves siderophores and cyclic lipopeptides. The third type colonizes above-ground plant parts. Strains from this type mainly belong to the P. syringae group and are used to control postharvest pathogens. This chapter starts with recent advances in Pseudomonas taxonomy and a summary of its most important biocontrol traits. It then provides an overview of the most important Pseudomonas groups and subgroups harboring biocontrol strains. Examples of well-characterized and representative biocontrol strains show the links between phylogeny, ecology and biocontrol traits. The chapter concludes by reviewing commercially-available biocontrol strains.

scholarly journals Genome Mining of Antimicrobial Gene Clusters from Phyllospheric Bacteria Isolated from Solanum Lycopersicum and Lactuca Sativa to Identify Biocontrol Properties

2021 ◽  
Author(s):  
Claudia Y. Muñoz ◽  
Lu Zhou ◽  
Yunhai Yi ◽  
Oscar P. Kuipers
Keyword(s):  
Antimicrobial Activity ◽  
Plant Growth ◽  
Plant Pathogens ◽  
Growth Promotion ◽  
Genome Mining ◽  
Gene Clusters ◽  
Biocontrol Agents ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Microbe Interactions

Abstract BackgroundBiocontrol agents are sustainable eco-friendly alternatives for chemical pesticides that cause adverse effects in the environment and toxicity in animals including humans. An improved understanding of the phyllosphere microbiology is of vital importance for biocontrol development. Most studies have been directed towards beneficial plant-microbe interactions and ignore the pathogens that might affect humans when consuming vegetables. In this study we extended this perspective and investigated potential biocontrol strains isolated from the tomato and lettuce phyllosphere that can promote plant growth and antagonize mammalian pathogens as well as plant pathogens. Subsequently, we mined into their genomes for discovery of antimicrobial biosynthetic gene clusters (BGCs), several of which are good candidates to produce protectants against microbial plant and mammalian pathogens.Results The antimicrobial activity of 69 newly isolated strains from a healthy tomato and lettuce phyllosphere against several plant and mammalian pathogens was determined with plates assays. Three strains with the highest antimicrobial activity against the relevant pathogens were selected and characterized (Bacillus subtilis STRP31, Bacillus velezensis SPL51, and Paenibacillus sp. PL91). All three strains showed a plant growth promotion effect by the production of volatile compounds (VOCs) on tomato and lettuce. In addition, genome mining of these isolates showed the presence of a large variety of biosynthetic gene clusters. A total of 39 BGCs were identified, of which several are already known, such as bacilysin, bacillibactin, surfactin, subtilomycin, etc., but also several novel ones. Further analysis revealed that among the novel BGCs, one NRPS and two bacteriocins are encoded which were analyzed in more depth.Conclusions Several antimicrobial BGCs were found in the selected strains, including the rediscovery of known ones, but also the discovery of novel ones. Our study serves as support for subsequent examination and characterization of novel antimicrobial metabolites, and the possibility of developing biocontrol agents.

The use of Bacillus spp. as bacterial biocontrol agents to control plant diseases

2021 ◽  
Author(s):  
Adrien Anckaert ◽  
◽  
Anthony Arguelles Arias ◽  
Grégory Hoff ◽  
Maryline Calonne-Salmon ◽  
...  
Keyword(s):  
Control Plant ◽  
Ecological Factors ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Diseases ◽  
Biocontrol Agents ◽  
Systemic Resistance ◽  
Health Improvement ◽  
Wide Range ◽  
Bacillus Spp ◽  
Plant Growth Promoting

Biocontrol agents (BCAs) based on plant growth promoting rhizobacteria have recently been developed as alternatives to chemical pesticides. Among those beneficial bacteria, Bacillus spp. are one of the most promising BCAs. A wide range of bioactive secondary metabolites (BSMs) are involved in biocontrol via antibiosis to phytopathogens and/or via elicitation of systemic resistance in their host plants. This chapter illustrates the diversity of pathosystems in which BCA based on Bacillus spp. have proved effective. It describes the mechanisms underpinning this biocontrol activity via production of a wide range of enzymes, proteins and small-size BSMs. As these BSMs are clearly involved in pathogen control, we emphasise the importance of understanding the ecological factors influencing their production. In the last part of the chapter, we highlight the potential interactions between Bacillus spp. and other soil microorganisms in developing consortia of biocontrol agents combining species with synergistic activities for plant health improvement.

scholarly journals Gentiana asclepiadea L. from Two High Mountainous Habitats: Inter- and Intrapopulation Variability Based on Species’ Phytochemistry

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 140
Author(s):  
Zorica Popović ◽  
Dijana Krstić-Milošević ◽  
Milena Marković ◽  
Vera Vidaković ◽  
Srđan Bojović
Keyword(s):  
Secondary Metabolites ◽  
Natural Populations ◽  
Chemical Compounds ◽  
Clear Separation ◽  
Plant Parts ◽  
Intrapopulation Variability ◽  
Population Origin

Natural populations of Gentiana asclepiadea L., located at two mountainous sites, were HPLC-analyzed regarding the contents of six representative secondary metabolites. The contents of swertiamarin (SWM), gentiopicrin (GP), sweroside (SWZ), mangiferin (MGF), isoorientin (ISOOR), and isovitexin (ISOV) were determined in six populations (three per study site), and separately for aboveground and belowground plant parts. PCA showed a clear separation of four groups according to the contents of the analyzed secondary metabolites. Out of six analyzed compounds, five were present in all samples and only one (SWZ) was found in Golija populations (belowground parts) but not in Vlasina populations, and its presence can be indicative of the geolocation of populations. Clear separation of groups was mostly affected by the different contents of chemical compounds in plant parts (aboveground versus belowground) and by the differences related to population origin (higher content of SWM and GP in belowground parts of individuals from Vlasina populations and higher content of MGF and ISOOR of individuals from Golija populations). The results of this study contribute to the spatiochemical profiling of G. asclepiadea populations and a better understanding of inter- and intrapopulation variability of pharmacologically important compounds.

scholarly journals Cytokinin Mediated Increased In Vitro Production of Secondary Metabolites with Special Reference to Solasodine in Solanum erianthum

2021 ◽  
Vol 8 (02) ◽  
pp. e62-e68
Author(s):  
Jeeta Sarkar ◽  
Nirmalya Banerjee
Keyword(s):  
Secondary Metabolites ◽  
High Performance ◽  
Culture Medium ◽  
In Vitro Production ◽  
Leaf Extracts ◽  
Plant Parts ◽  
Regenerated Plants ◽  
Vitro Production ◽  
Regenerated Plantlets

AbstractSteroid alkaloid solasodine is a nitrogen analogue of diosgenin and has great importance in the production of steroidal medicines. Solanum erianthum D. Don (Solanaceae) is a good source of solasodine. The aim of this study was to evaluate the effect of different cytokinins on the production of secondary metabolites, especially solasodine in the in vitro culture of S. erianthum. For solasodine estimation, field-grown plant parts and in vitro tissues were extracted thrice and subjected to high-performance liquid Chromatography. Quantitative analysis of different secondary metabolites showed that the amount was higher in the in vitro regenerated plantlets compared to callus and field-grown plants. The present study critically evaluates the effect of the type of cytokinin used in the culture medium on solasodine accumulation in regenerated plants. The highest solasodine content (46.78±3.23 mg g-1) was recorded in leaf extracts of the in vitro grown plantlets in the presence of 6-γ,γ-dimethylallylamino purine in the culture medium and the content was 3.8-fold higher compared to the mother plant.

scholarly journals Pseudomonas sp. COW3 Produces New Bananamide-Type Cyclic Lipopeptides with Antimicrobial Activity against Pythium myriotylum and Pyricularia oryzae

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4170 ◽  
Author(s):  
Olumide Owolabi Omoboye ◽  
Niels Geudens ◽  
Matthieu Duban ◽  
Mickaël Chevalier ◽  
Christophe Flahaut ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Genome Mining ◽  
Antagonistic Activity ◽  
Pyricularia Oryzae ◽  
Pseudomonas Sp ◽  
Pythium Myriotylum ◽  
Cyclic Lipopeptides ◽  
Peptide Synthetase ◽  
Kendrick Mass Defect

Pseudomonas species are metabolically robust, with capacity to produce secondary metabolites including cyclic lipopeptides (CLPs). Herein we conducted a chemical analysis of a crude CLP extract from the cocoyam rhizosphere-derived biocontrol strain Pseudomonas sp. COW3. We performed in silico analyses on its whole genome, and conducted in vitro antagonistic assay using the strain and purified CLPs. Via LC-MS and NMR, we elucidated the structures of four novel members of the bananamide group, named bananamides D-G. Besides variability in fatty acid length, bananamides D-G differ from previously described bananamides A-C and MD-0066 by the presence of a serine and aspartic acid at position 6 and 2, respectively. In addition, bananamide G has valine instead of isoleucine at position 8. Kendrick mass defect (KMD) allowed the assignment of molecular formulae to bananamides D and E. We unraveled a non-ribosomal peptide synthetase cluster banA, banB and banC which encodes the novel bananamide derivatives. Furthermore, COW3 displayed antagonistic activity and mycophagy against Pythium myriotylum, while it mainly showed mycophagy on Pyricularia oryzae. Purified bananamides D-G inhibited the growth of P. myriotylum and P. oryzae and caused hyphal distortion. Our study shows the complementarity of chemical analyses and genome mining in the discovery and elucidation of novel CLPs. In addition, structurally diverse bananamides differ in their antimicrobial activity.

scholarly journals Perception of Biocontrol Potential of Bacillusinaquosorum KR2-7 against Tomato Fusarium Wilt through Merging Genome Mining with Chemical Analysis

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 137
Author(s):  
Maedeh Kamali ◽  
Dianjing Guo ◽  
Shahram Naeimi ◽  
Jafar Ahmadi
Keyword(s):  
Chemical Analysis ◽  
Plant Growth ◽  
Fusarium Wilt ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Genome Mining ◽  
Gene Clusters ◽  
Systemic Resistance ◽  
Plant Colonization ◽  
Biocontrol Potential

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.

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