Lipopolysaccharide of Pantoea agglomerans 7460: O-specific polysaccharide and lipid A structures and biological activity

Zdorovenko, Evelina L.; Kadykova, Alexandra A.; Shashkov, Alexander S.; Varbanets, L.D.; Bulyhina, T.V.; Knirel, Yuriy A.

doi:10.1016/j.carres.2020.108132

Cited by 2 publications

(2 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present study, we report the in vitro antiviral activities and interaction of LPS and its structural components with TMV, since the effect of the product "Gaupsin" on the antiviral activity were previously shown [10,11]. LPS from nine strains of the phytopathogenic phytopathogenic bacterium P. agglomerans were isolated and chemically characterized by us earlier [17][18][19][20][21][22][23]. The individual structural components of the LPS macromolecule was obtained by mild acid hydrolysis, in which insoluble lipid A and water-soluble O-specific polysaccharide (OPS) and core oligosaccharide (OG-core) fractions were obtained.…”

Section: Methodsmentioning

confidence: 94%

Anti-TMV Activities of Pantoea agglomerans Lipopolysaccharides in vitro

Bulyhina¹,

Kyrychenko²,

Kharchuk³

et al. 2021

Mikrobiol. Z.

View full text Add to dashboard Cite

Today there are no antiviral drugs of chemical nature that can completely cure virus-infected plants. The fact that their effect is limited to minimizing the pathogenic effect of viruses motivates many researchers to look for alternatives. In recent years it has been shown that lipopolysaccharides (LPS) of some bacteria, in particular representatives of the Pseudomonas genus were active against Tobacco mosaic virus (TMV). Therefore, we were interested in the additional study of LPS of phytopathogenic bacteria Pantoea agglomerans as a possible drug acting as antiviral agent. The aim of current study was to evaluate the antiviral activities of LPS obtained from phytopathogenic bacteria P. agglomerans against TMV in vitro. Methods. The antiviral activity of LPS preparations was investigated in vitro and assessed according to the inhibition percentage towards the number of local lesions in Datura stramonium leaves. P. agglomerans LPS was isolated from dry bacterial mass by phenol-water method. LPS mild acid degradation allowed to separate O-specific polysaccharide (OPS) and lipid A, which structures were identified by us earlier. The analysis of TMV and LPS interactions was carried out using a JEM 1400 transmission electron microscope (Jeol, Japan) at an accelerating voltage of 80 kV. Results. The most active were LPS preparations from P. agglomerans P324 and 8488. In vitro inhibitory efficacies of TMV infection by these LPS preparations was 59 and 60% respectively. LPS preparations of P. agglomerans 7969, 7604 and 9637, on the contrary, were inactive. Comparative analysis of the antiviral activity of LPS structural components of two P. agglomerans P324 and 7604 strains showed that the greatest inhibitory effect on the infectivity of TMV was exhibited by P. agglomerans P324 lipid A, the antiviral activity of which practically did not differ from the activity of the LPS molecule (it was lower by 7%). At the same time, the inhibitory effect of P. agglomerans 7604 core oligosaccharide (OG-core) against TMV was slightly higher compared to the effect of the whole LPS molecule. It can be assumed that the OG-core stimulated the defense mechanisms of plants and prevented the development of viral infection. Electron microscopic dates have shown that P. agglomerans P324 LPS at the concentration of 1 mg/ml influenced on freely located virions in the control causing “sticking” thus forming dense clusters, complexes or “bundles” of the virus. The individual structural components of P. agglomerans P324 LPS (lipid A and OG-core) did not have the same effect as a whole molecule. Conclusions. The study of the antiviral activity of LPS in the model system TMV – Datura stramonium L. plants showed that the most active were LPS preparations of only two strains of P. agglomerans (P324 and 8488) while the other seven strains were inactive. Individual structural components: lipid A from P. agglomerans P324 and OG-core from P. agglomerans 7604 decreased the infectivity of TMV by 7 and 15% higher than the initial LPS molecule. According to electron microscopy data the virions sticked together forming the dense clusters in case of the direct LPS-virus contacting in vitro whereas in the control it was observed just a single free virus particles. A more detailed study of the effect of individual structural components will help to understand the regularities of the LPS structure effect on TMV infectivity.

show abstract

Section: Methodsmentioning

confidence: 94%

Anti-TMV Activities of Pantoea agglomerans Lipopolysaccharides in vitro

Bulyhina¹,

Kyrychenko²,

Kharchuk³

et al. 2021

Mikrobiol. Z.

View full text Add to dashboard Cite

show abstract

“…Phytotoxins play an important role in the pathogenesis of plants, as they may determine the development of the disease (Zdorovenko EL et al, 2020;Portal González et al, 2021). The synthesis of phytotoxins is a characteristic feature of necrotrophic pathogens, which defi nes a wide spectrum of host plants (Medina R et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Plant growth regulatory activity in the phytopathogenic fungus Plectosphaerella melonis strain 502

Tsekhmister¹,

Kyslynska²,

Кopilov³

et al. 2021

Agric. sci. pract.

View full text Add to dashboard Cite

Aim. To investigate the ability of our phytopathogenic fungal strain 502, earlier preliminarily identified as the phytopathogen Plectosphaerella melonis (syn. Acremonium cucurbitacearum), to have phytotoxic and/or plant growth regulatory activity. Methods. The phytotoxicity of strain 502, was studied by bioassays using the test cultures of corn (Zea mays L.), garden cress (Lepidium sativum L.), cucumber (Cucumis sativus L.), and onion (Allium cepa L.). The cytotoxicity and genotoxicity of the fungus were estimated using the Allium cepa-test. The mitotic index of the, the duration of mitosis phases, and the frequency of aberrant ana-telophases of Allium cepa L. roots meristem was also investigated. For this purpose, strain 502, was grown in the following culture media: synthetic Raulin-Thom medium for 10 days at 26 ± 2 °С. Cell-free filtrate (culture fluid) was used for the study. Ethylene production was quantified in culture filtrate using gas-chromatography meth- od. Ethylene measurement was performed every 7 days during 8 weeks. The determination was carried out using a gas chromatograph «Agilent Technologies 6850» (USA) fitted with a flame ionization detector, using commercial ethylene as a standard for identification and quantification Every experiment had three repeats. The reliability of experimental data was assessed by statistical methods using Statistica 12 (Stat-Soft Inc., USA). Results. Undiluted culture fluid (obtained by growing the fungus on liquid wort) of our strain 502 inhibited the growth of Z. mays seedlings by 14 %, L. sativum seedlings by 18 % (1 : 100 dilution) and stimulated the growth of L. sativum roots by 54 and 41 % (1 : 10 and 1 : 100 dilutions, respectively). The culture fluid, obtained by growing the fungus on Raulin-Thom’s synthetic agar, demonstrated a slight inhibitory effect on the seedlings and roots of L. sativum, and at the dilution of 1 : 1000 stimulated growth by 30 %. Insignificant changes in the mitotic index of the meristem of A. cepa roots were revealed at the effect of the culture fluid of P. melonis, strain 502, diluted at the ratio of 1 : 100 and 1 : 1000. At the same time, the number of cells at the prophase stage decreased 1.7 times (1 : 100 dilution). There is a significant increase in the number of cells at the metaphase stage – 1.3 and 1.4 times (dilution 1 : 100 and 1 : 1000, respectively), the anaphase stage – 2.1 and 1.8 times (dilution 1 : 100 and 1 : 1000, respectively) and the telophase stage – 1.8 times (1 : 100 dilution), as compared with the positive control (culture medium). The frequencies of aberrant ana-telophases in the apical meristems of the initial roots were 5.0 and 2.2 % (at the culture fluid dilution of 1 : 100 and 1 : 1000, respectively). We researched the abil- ity of P. melonis 502 to synthesize ethylene and the highest level of it was registered after 5 weeks of cultivation (111.78 nmol/h g). Conclusions: It was demonstrated by us that the culture fluid of strain 502 showed no phytotoxic effect on roots and seedlings of the investigated cultures, demonstrating the exclusion of phytotoxins from the possible range of effectors. No cytotoxic or genotoxic activity of the culture fluid was observed either. However, the culture fluid altered the dynamics of the cell cycle, in particular, shortened the prophase and stimulated the metaphase, anaphase, and telophase. The culture fluid of the fungus stimulated the growth of L. sativum roots depending on the nutrient medium, where the fungus was grown and cultivated. In particular, when growing the fungus on the liquid wort, the growth was higher by 54 and 41 % (dilution 1 : 10 and 1 : 100, respectively), when growing on synthetic Raulin-Thom’s medium – by 30 %. This demonstrates the ability of strain 502 to possibly synthesize growth promoting substances. Also, we have shown the ability of this strain to synthetize ethylene in vitro (111.78 ± 13.27 nmol/h per g), which can act as virulence factor. We consider the obtained results to be the first stage of the study on the mechanism of the interaction between pathogenic strain 502 and plants.

show abstract

Lipopolysaccharide of Pantoea agglomerans 7460: O-specific polysaccharide and lipid A structures and biological activity

Cited by 2 publications

References 36 publications

Anti-TMV Activities of Pantoea agglomerans Lipopolysaccharides in vitro

Anti-TMV Activities of Pantoea agglomerans Lipopolysaccharides in vitro

Plant growth regulatory activity in the phytopathogenic fungus Plectosphaerella melonis strain 502

Contact Info

Product

Resources

About