Ядерна фізика та енергетика Nuclear Physics and Atomic Energy   ISSN: 1818-331X (Print), 2074-0565 (Online)   Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine   Languages: Ukrainian, English   Periodicity: 4 times per year   Open access peer reviewed journal

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J. Shylina¹, I. Zhuk^1,*, O. Molozhava², J. Shevchenko<sup>3

1</sup>.Institute of Cell Biology and Genetic Engineering, National Academy of Sciences of Ukraine, Kyiv, Ukraine
² Educational and Scientific Centre "Institute of Biology and Medicine" of the Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
³ Syngenta Group AG, Basel, Switzerland

^*Corresponding author. E-mail address: ivzhukvi@gmail.com

Abstract: The impact of chronic gamma irradiation (8 days, dose rate 12 μcGy/s, absorbed dose 8.29 cGy) on Pseudomonas aeruginosa strains IMV 9024, IMV 9095, and IMV 9096 was investigated. Irradiation of phytopathogenic strains IMV 9024 and IMV 9096 enhanced their phytotoxic activity, whereas in strain IMV 9095, it primarily promoted bacterial growth. In addition, irradiation stimulated pigment biosynthesis, notably the production of pyocyanin (in all examined strains, with the strongest effect in IMV 9024) and pyomelanin (in IMV 9024 and IMV 9096, most prominently in IMV 9024). The persistence of elevated phytotoxic activity across multiple bacterial generations following infection suggests the involvement of epigenetic regulatory mechanisms sustaining virulence factor expression. Collectively, these findings demonstrate that chronic low-dose irradiation can induce substantial alterations in plant–phytopathogen interactions.

Keywords: chronic gamma irradiation, Pseudomonas aeruginosa strains IMV 9024, IMV 9095, IMV 9096, pyocyanin, pyomelanin, phytotoxic activity.

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