Joanna Deckert,2 and
1Department of Plant Physiology, Poznan University of Life Sciences, Wołynska 35, 60-637 Poznan, Poland; 2Department of Plant Ecophysiology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland; 3Institute of Chemistry and Technical Electrochemistry, Poznan University of Technology, Piotrowo 3, Poznan, Poland; 4Department of Experimental Anaesthesiology, the Poznan University of Medical Sciences, Sw. Marii Magdaleny 14, 60-861 Poznan, Poland
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Accepted 11 July 2012.
We investigated how potato exposed to a chemical agent could activate nitric oxide (NO)-dependent events facilitating more potent defense responses to a subsequent pathogen attack. Obtained data revealed that all applied inducers, i.e., β-aminobutyric acid (BABA), γ-aminobutyric acid (GABA), laminarin, or 2,6-dichloroisonicotinic acid (INA), were active stimuli in potentiating NO synthesis in the primed potato. It is assumed, for the mechanism proposed in this paper, that priming involves reversible S-nitrosylated protein (S-nitrosothiols [SNO]) storage as one of the short-term stress imprint components, apart from epigenetic changes sensitized by NO. Based on BABA- and GABA-induced events, it should be stated that a rise in NO generation and coding the NO message in SNO storage at a relatively low threshold together with histone H2B upregulation might create short-term imprint activation, facilitating acquisition of a competence to react faster after challenge inoculation. Laminarin elicited strong NO upregulation with an enhanced SNO pool–altered biochemical imprint in the form of less effective local recall, nevertheless being fully protective in distal responses against P. infestans. In turn, INA showed the most intensified NO generation and abundant formation of SNO, both after the inducer treatment and challenge inoculation abolishing potato resistance against the pathogen. Our results indicate, for the first time, that a precise control of synthesized NO in cooperation with reversible SNO storage and epigenetic modifications might play an important role in integrating and coordinating defense potato responses in the priming phenomenon.
© 2012 The American Phytopathological Society