Page 31 - Book of Abstracts

5 International Scientific Online Conference DOI: https://doi.org/10.15414/2021.9788055224015

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PHYTOTOXICITY OF NATIVE AND MODIFIED LIPOPOLYSACCHARIDES OF PANTOE
AGGLOMERANS, PSEUDOMONAS PUTIDA, P. CHLORORAPHIS SUBSP. CHLORORAPHIS AND
ESCHERICHIA COLI

Tetiana Bulyhina, Oksana Brovarska
D.K. Zabolotny Institute of Microbiology and Virology of the National Academy of Science of Ukraine,
Kyiv, Ukraine; E-mail.: dascaliuca@yahoo.com
When studying the interaction of plants with associative and pathogenic microflora, an
important issue is the role of surface structures of microorganisms in their recognition of the
host plant and interaction with plant cells. Lipopolysaccharides (LPSs) are one of the main
components of the outer membrane of cells of gram-negative bacteria involved in their
interaction with other organisms. A number of studies have shown that they can act as an agent
of innate plant immunity and can induce such reactions of plant cells as oxidative burst, NO
synthesis, the influx of calcium ions into cells, changes in the cell wall with deposition of calose
and phenolic compounds, induction or inhibition of hypersensitivity reactions. The effect of
LPSs preparations on plants is also associated with their direct toxic effect, which is mainly due
to the ability of the LPSs molecule to easily bind with various cells of the microorganism.
It is known that the biological activity of LPSs largely depends on the method of their
isolation, chemical structure, and conformation of the molecule. A change in the biological
properties of LPSs as a result of chemical treatment is associated with a change in the
conformation of LPSs molecules. The research aimed to investigate changes in the phytotoxic
activity of native and modified LPSs.
Phytotoxicity was determined on the seeds of salate, calculating the root and pagon index
(test indicators). To reveal the effect of LPSs on germination energy, lettuce seeds were soaked
for 2 hours in solutions of native and modified LPSs (1 mg/ml). LPSs modification was carried
out by succinylation and two LPSs (Pseudomonas putida and Pantoea agglomerans 7460) were
modified using succinic acid and germanium.
It was found that the studied native and modified LPS both stimulated and suppressed the
growth of roots and sprouts. Thus, three modified LPSs had a stimulating effect on roots and/or
sprouts, while three other native LPSs had an inhibiting effect on the growth of both roots and
sprouts. In addition, not all modified LPSs had a stimulating effect on the root and sprout index.
An interesting fact is that the modified LPS of Pseudomonas chlororaphis subsp.
chlororaphis UKM-106 (+10 C – temperature of cultivation) had a more stimulating effect on
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the growth of roots and sprouts (by 7 and 12 %, respectively) than native LPS. In turn, the
modified LPS of Pantoea agglomerans 7460 had the greatest stimulating effect on root growth,
and modified LPS Pseudomonas chlororaphis subsp. chlororaphis (+28 C – temperature of
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cultivation), even compared to native LPS (≈ 31 and 18 %, respectively).
Modification of E. coli 2890, 2892 LPSs had almost no effect on the phytotoxicity; it's even
slightly increased the negative effect on root growth, although it had a small stimulating effect
on sprouts growth.
Thus, the results obtained indicate that the studied native and modified LPSs during seed
treatment are characterized by different effects on the development of seedlings, depending on
the strain from which they are isolated and the method of modification.
Keywords: Pantoea agglomerans, Pseudomonas putida, P. chlororaphis subsp. chlororaphis, Escherichia
coli, succinylated lipopolysaccharide, phytotoxicity.

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5 International Scientific Conference Agrobiodiversity for Improving the Nutrition, Health, Quality of Life and |30
Spiritual Human Development
November 3 2021
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