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Plant Cell Reports Nov 2023The novel interkingdom PGPM consortia enhanced the ability of plant growth promotion and disease resistance, which would be beneficial to improve plant growth in...
The novel interkingdom PGPM consortia enhanced the ability of plant growth promotion and disease resistance, which would be beneficial to improve plant growth in sustainable agriculture through engineering microbiome. Plant growth-promoting microbes (PGPMs) play important roles in promoting plant growth and bio-controlling of pathogens. Much information reveals that the plant growth-promoting ability of individual PGPM affects plant growth. However, the effects of the PGPM consortia properties on plant growth remain largely unexplored. Here, we characterized three new PGPM strains including Rhodotorula graminis JJ10.1 (termed as J), Pseudomonas psychrotolerans YY7 (termed as Y) and P. chlororaphis T8 (termed as T), and assessed their effects in combination with Bacillus amyloliquefaciens FZB42 (termed as F) on plant growth promotion and disease prevention in Arabidopsis thaliana and tomato (Solanum lycopersicum) plants by investigating morphological changes, whole-genome sequencing and plant growth promoting (PGP) characterization. Results revealed that the three new strains R. graminis JJ10.1, P. psychrotolerans YY7 and P. chlororaphis T8 had the potential for being combined with B. amyloliquefaciens FZB42 to form interkingdom PGPM consortia. The combinations of R. graminis JJ10.1, B. amyloliquefaciens FZB42, and P. psychrotolerans YY7, i. e. JF and JYF, exhibited the strongest ability of synergetic biofilm production. Furthermore, the growth-promotion abilities of the consortia were significantly enhanced compared with those of individual strains under both inoculation and volatile organic compounds (VOCs) treatment. Importantly, the consortia showed stronger abilities of in planta disease prevention than individual strains. Findings of our study may provide future guidance for engineering the minimal microbiome communities to improve plant growth and/or disease resistance in sustainable agriculture.
Topics: Disease Resistance; Plant Development; Solanum lycopersicum; Arabidopsis
PubMed: 37674059
DOI: 10.1007/s00299-023-03060-3 -
Folia Microbiologica Aug 2023Volatile compounds emitted by bacteria can play a significant role in interacting with microorganisms, plants, and other organisms. In this work, we studied the effect...
Volatile compounds emitted by bacteria can play a significant role in interacting with microorganisms, plants, and other organisms. In this work, we studied the effect of total gaseous mixtures of organic as well as inorganic volatile compounds (VCs) and individual pure volatile organic compounds (VOCs: ketones 2-nonanone, 2-heptanone, 2-undecanone, a sulfur-containing compound dimethyl disulfide) synthesized by the rhizosphere Pseudomonas chlororaphis 449 and Serratia plymuthica IC1270 strains, the soil-borne strain P. fluorescens B-4117, and the spoiled meat isolate S. proteamaculans 94 strain on Arabidopsis thaliana plants (on growth and germination of seeds). We demonstrated that total mixtures of volatile compounds emitted by these strains grown on Luria-Bertani agar, Tryptone Soya Agar, and Potato Dextrose Agar media inhibited the A. thaliana growth. When studied bacteria grew on Murashige and Skoog (MS) agar medium, volatile mixtures produced by bacteria could stimulate the growth of plants. Volatile compounds of bacteria slowed down the germination of plant seeds; in the presence of volatile mixtures of P. fluorescens B-4117, the seeds did not germinate. Of the individual VOCs, 2-heptanone had the most potent inhibitory effect on seed germination. We also showed that the tested VOCs did not cause oxidative stress in Escherichia coli cells using specific lux-biosensors. VOCs reduced the expression of the lux operon from the promoters of the katG, oxyS, and soxS genes (whose products involved in the protection of cells from oxidative stress) caused by the action of hydrogen peroxide and paraquat, respectively.
Topics: Pseudomonas; Agar; Escherichia coli; Serratia; Volatile Organic Compounds
PubMed: 36790684
DOI: 10.1007/s12223-023-01038-y -
Microbial Ecology Aug 2023Aquaponics is defined as a sustainable and integrated system that combines fish aquaculture and hydroponic plant production in the same recirculated water loop. A recent...
First Study Case of Microbial Biocontrol Agents Isolated from Aquaponics Through the Mining of High-Throughput Sequencing Data to Control Pythium aphanidermatum on Lettuce.
Aquaponics is defined as a sustainable and integrated system that combines fish aquaculture and hydroponic plant production in the same recirculated water loop. A recent study using high-throughput sequencing (HTS) technologies highlighted that microbial communities from an aquaponic system could control one of the most problematic pathogens in soilless lettuce culture, namely, Pythium aphanidermatum. Therefore, this study aims at isolating the microorganisms responsible for this biocontrol action. Based on the most promising genera identified by HTS, an innovative strategy for isolating and testing original biocontrol agents from aquaponic water was designed to control P. aphanidermatum. Eighty-two bacterial strains and 18 fungal strains were isolated, identified by Sanger sequencing, and screened in vivo to control damping-off of lettuce seeds caused by P. aphanidermatum. Out of these 100 isolates, the eight most efficacious ones were selected and further tested individually to control root rot disease caused by the same pathogen at a later stage of lettuce growth. Strains SHb30 (Sphingobium xenophagum), G2 (Aspergillus flavus), and Chito13 (Mycolicibacterium fortuitum) decreased seed damping-off at a better rate than a propamocarb fungicide and a Pseudomonas chlororaphis registered biocontrol agent did. In root rot bioassays, lettuce mortality was prevented by applying strains G2 and Chito13, which were at least as efficacious as the fungicide or biopesticide controls. Lettuce disease symptoms and mortality were eradicated by strain SHb30 in the first bioassay, but not in the second one. These results show that aquaponic systems are promising sources of original biocontrol agents, and that HTS-guided strategies could represent interesting approaches to identify new biocontrol agents.
Topics: Animals; Fungicides, Industrial; Pythium; Lactuca; Pest Control, Biological; Plant Diseases; Water; High-Throughput Nucleotide Sequencing
PubMed: 36334118
DOI: 10.1007/s00248-022-02126-1 -
Polymers Nov 2023The use of biocidal agents is a common practice for protection against biofouling in biomass-rich environments. In this paper, oligohexamethyleneguanidine (OHMG)...
The use of biocidal agents is a common practice for protection against biofouling in biomass-rich environments. In this paper, oligohexamethyleneguanidine (OHMG) polymer, known for its biocidal properties, was further modified with para-aminosalicylic acid (PAS) to enhance its properties against microorganisms coated with a lipid membrane. The structure of the product was confirmed by H NMR, C NMR, and FTIR spectroscopy. The values of the minimum inhibitory concentration (MIC) against ATCC 607 and 449 were found to be 1.40 and 1.05 μg/mL, respectively. The synthesized substance was used as an additive to the polymer matrix of the composite optical oxygen sensor material. A series of samples with different contents of OHMG-PAS was prepared using a co-dissolution method implying the fabrication of a coating from a solution containing both polymers. It turned out that the mutual influence of the components significantly affects the distribution of the indicator in the matrix, surface morphology, and contact angle. The optimal polymer content turned out to be wt.3%, at which point the water contact angle reaches almost 122°, and the fouling rate decreases by almost five times, which is confirmed by both the respiratory MTT assay and confocal microscopy with staining. This opens up prospects for creating stable and biofouling-resistant sensor elements for use in air tanks or seawater.
PubMed: 38231936
DOI: 10.3390/polym15234508 -
Microbial Ecology Oct 2023Combining different biocontrol agents (BCA) is an approach to increase efficacy and reliability of biological control. If several BCA are applied together, they have to...
Combining different biocontrol agents (BCA) is an approach to increase efficacy and reliability of biological control. If several BCA are applied together, they have to be compatible and ideally work together. We studied the interaction of a previously selected BCA consortium of entomopathogenic pseudomonads (Pseudomonas chlororaphis), nematodes (Steinernema feltiae associated with Xenorhabdus bovienii), and fungi (Metarhizium brunneum). We monitored the infection course in a leaf- (Pieris brassicae) and a root-feeding (Diabrotica balteata) pest insect after simultaneous application of the three BCA as well as their interactions inside the larvae in a laboratory setting. The triple combination caused the highest mortality and increased killing speed compared to single applications against both pests. Improved efficacy against P. brassicae was mainly caused by the pseudomonad-nematode combination, whereas the nematode-fungus combination accelerated killing of D. balteata. Co-monitoring of the three BCA and the nematode-associated Xenorhabdus symbionts revealed that the four organisms are able to co-infect the same larva. However, with advancing decay of the cadaver there is increasing competition and cadaver colonization is clearly dominated by the pseudomonads, which are known for their high competitivity in the plant rhizosphere. Altogether, the combination of the three BCA increased killing efficacy against a Coleopteran and a Lepidopteran pest which indicates that this consortium could be applied successfully against a variety of insect pests.
Topics: Animals; Reproducibility of Results; Pest Control, Biological; Insecta; Larva; Rhabditida; Plant Leaves
PubMed: 36849610
DOI: 10.1007/s00248-023-02191-0 -
Journal of Contaminant Hydrology Feb 2024Despite the serious health threats due to wide use of organophosphorus pesticides (OPPs) have been experimentally claimed to be remediated by probiotic microorganisms in...
Despite the serious health threats due to wide use of organophosphorus pesticides (OPPs) have been experimentally claimed to be remediated by probiotic microorganisms in various food and organism models, the interactions between OPPs and probiotics in the natural wetland ecosystem was rarely investigated. This study delves into the spatial and temporal distribution, contamination levels of OPPs in the Baiyangdian region, the diversity of probiotic communities in varying environmental contexts, and the potential connection with OPPs on these probiotics. In typical shallow lake wetland ecosystem-Baiyangdian lake in north China, eight OPPs were identified in the lake sediments, even though their detection rates were generally low. Malathion exhibited the highest average content among these pesticides (9.51 ng/g), followed by fenitrothion (6.70 ng/g). Conversely, chlorpyrifos had the lowest detection rate at only 2.14%. The region near Nanliu Zhuang (F10), significantly influenced by human activities, displayed the highest concentration of total OPPs (136.82 ng/g). A total of 145 probiotic species spanning 78 genera were identified in Baiyangdian sediments. Our analysis underscores the relations of environmental factors such as phosphatase activity, pH, and electrical conductivity (EC) with probiotic community. Notably, several high-abundance probiotics including Pseudomonas chlororaphis, Clostridium sp., Lactobacillus fermentum, and Pseudomonas putida, etc., which were reported to exhibit significant potential for the degradation of OPPs, showed strongly correlations with OPPs in the Baiyangdian lake sediments. The outcomes of this research offer valuable insights into the spatiotemporal dynamics of OPPs in natural large lake wetland and the probability of their in-situ residue bioremediation through the phosphatase pathway mediated by probiotic such as Lactic acid bacteria in soils/sediments contaminated with OPPs.
Topics: Humans; Pesticides; Organophosphorus Compounds; Ecosystem; Lakes; Phosphoric Monoester Hydrolases; China; Geologic Sediments; Environmental Monitoring
PubMed: 38244424
DOI: 10.1016/j.jconhyd.2024.104306 -
Environmental Science & Technology Jun 2024Rhizosphere iron plaques derived from Fe-based nanomaterials (NMs) are a promising tool for sustainable agriculture. However, the requirement for flooded conditions to...
Rhizosphere iron plaques derived from Fe-based nanomaterials (NMs) are a promising tool for sustainable agriculture. However, the requirement for flooded conditions to generate iron plaque limits the scope of the NM application. In this study, we achieved Fenton oxidation of a highly chlorinated persistent organic pollutant (2,2',4,5,5'-pentachlorobiphenyl, PCB101) through iron plaque mediated by the interaction between α-FeO NMs and plant-rhizobacteria symbionts under dryland conditions. Mechanistically, the coexistence of α-FeO NMs and JD37 stimulated alfalfa roots to secrete acidic and reductive agents as well as HO, which together mediated the rhizosphere Fenton reaction and converted α-FeO NMs into iron plaque rich in Fe(II)-silicate. Further verifications reproduced the Fenton reaction using α-FeO NMs and rhizosphere compounds, confirming the critical role of •OH in the oxidative degradation of PCB101. Significant reductions in PCB101 content by 18.6%, 42.9%, and 23.2% were respectively found in stem, leaf, and soil after a 120-d treatment, proving the effectiveness of this NMs-plant-rhizobacteria technique for simultaneously safe crop production and soil remediation. These findings can help expand the potential applications of nanobio interaction and its mediated iron plaque generation for both agricultural practice and soil remediation.
Topics: Iron; Soil Pollutants; Nanostructures; Ferric Compounds; Soil; Rhizosphere
PubMed: 38869036
DOI: 10.1021/acs.est.4c03133 -
World Journal of Microbiology &... Aug 2023Phenazines are heteroaromatic compounds consisting of a central pyrazine ring fused with two benzenes. Different functional groups attached to the dibenzopyrasin core...
Phenazines are heteroaromatic compounds consisting of a central pyrazine ring fused with two benzenes. Different functional groups attached to the dibenzopyrasin core cause differences in the chemical, physical, and biological properties of phenazines. Interest in these compounds has not diminished for decades. New biological activities and practical applications discovered in recent years force researchers to investigate all aspects of the synthesis, degradation, and mechanisms of action of phenazines. In this study, we have demonstrated the involvement of the coxA gene product (cytochrome c oxidase, su I) in the production of phenazines in P. chlororaphis subsp. aurantiaca. Overlap PCR was used to knock out the coxA gene and the resulting mutants were screened for their ability to grow on rich and minimal culture media and for phenazine production. The reintroduction of the full-length coxA gene into the B-162/coxA strains was used to further confirm the role of this gene product in the ability to produce phenazines. We were able to show that the product of the coxA gene is necessary for phenazine production in rich growth media. At the same time, the CoxA protein does not seem to have any effect on phenazine production in M9 minimal salt medium. We could show that knocking down even one subunit of the cytochrome c oxidase complex leads to a significant reduction (to trace concentrations) or complete suppression of phenazine antibiotic production on rich PCA medium in P. chlororaphis subsp. aurantiaca.
Topics: Electron Transport Complex IV; Pseudomonas; Phenazines; Bacterial Proteins
PubMed: 37583000
DOI: 10.1007/s11274-023-03685-2 -
Heliyon Feb 2024This study aimed to isolate and characterize plant growth-promoting rhizobacteria from the faba bean rhizosphere for future inoculum production. For this purpose,127...
This study aimed to isolate and characterize plant growth-promoting rhizobacteria from the faba bean rhizosphere for future inoculum production. For this purpose,127 dissimilar rhizobacterial colonies were isolated. All isolated colonies were tested for plant growth-promoting traits. Based on their multiple plant growth-promoting traits, eight potential isolates were selected and identified GY01, GY03, and GY08 are affiliated with Acinetobacter sp. GY04 and GY05 are affiliated with Chryseobacterium sp. GY06 and GY07 are affiliated with Pseudomonas costantinii and Pseudomonas chlororaphis, respectively; and GY02 is affiliated with the Bacterium strain. All eight isolates were evaluated for their effects on seed germination and vigor index and potential antagonism against Botrytis fabae. Selected isolates showed positive effects on seed germination and vigor index with different potentials. Isolate GY04 resulted in the highest vigor index (501), while isolate GY08 achieved the lowest (218). B. fabae radial growth inhibition was found in all eight isolates. The isolates inhibited the radial growth of the test pathogen with an inhibition efficacy of 72.38 % in GY04 to 25.57 % in GY-03. Generally, the results of this study indicated the potential of these isolates as a microbial inoculant with multiple functions for faba beans.
PubMed: 38318010
DOI: 10.1016/j.heliyon.2024.e25334 -
BMC Plant Biology Feb 2024Crown gall disease caused by Agrobacterium tumefaciens is a very destructive affliction that affects grapevines. Endophytic bacteria have been discovered to control...
Antivirulence effects of cell-free culture supernatant of endophytic bacteria against grapevine crown gall agent, Agrobacterium tumefaciens, and induction of defense responses in plantlets via intact bacterial cells.
BACKGROUND
Crown gall disease caused by Agrobacterium tumefaciens is a very destructive affliction that affects grapevines. Endophytic bacteria have been discovered to control plant diseases via the use of several mechanisms. This research examined the potential for controlling crown gall by three endophytic bacteria that were previously isolated from healthy cultivated and wild grapevines including Pseudomonas kilonensis Ba35, Pseudomonas chlororaphis Ba47, and Serratia liquefaciens Ou55.
RESULT
At various degrees, three endophytic bacteria suppressed the populations of A. tumefaciens Gh1 and greatly decreased the symptoms of crown gall. Furthermore, biofilm production and motility behaviors of A. tumefaciens Gh1were greatly inhibited by the Cell-free Culture Supernatant (CFCS) of endophytic bacteria. According to our findings, CFCS may reduce the adhesion of A. tumefaciens Gh1 cells to grapevine cv. Rashe root tissues as well as their chemotaxis motility toward the extract of the roots. When compared to the untreated control, statistical analysis showed that CFCS significantly reduced the swimming, twitching, and swarming motility of A. tumefaciens Gh1. The findings demonstrated that the endophytic bacteria effectively stimulated the production of plant defensive enzymes including superoxide dismutase (SOD), polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), and total soluble phenols at different time intervals in grapevine inoculated with A. tumefaciens Gh1. The Ba47 strain markedly increased the expression levels of defense genes associated with plant resistance. The up-regulation of PR1, PR2, VvACO1, and GAD1 genes in grapevine leaves indicates the activation of SA and JA pathways, which play a role in enhancing resistance to pathogen invasion. The results showed that treating grapevine with Ba47 increased antioxidant defense activities and defense-related gene expression, which reduced oxidative damage caused by A. tumefaciens and decreased the incidence of crown gall disease.
CONCLUSION
This is the first study on how A. tumefaciens, the grapevine crown gall agent, is affected by CFCS generated by endophytic bacteria in terms of growth and virulence features. To create safer plant disease management techniques, knowledge of the biocontrol processes mediated by CFCS during microbial interactions is crucial.
Topics: Plant Tumors; Agrobacterium tumefaciens; Plant Diseases; Bacteria
PubMed: 38336608
DOI: 10.1186/s12870-024-04779-1