GROSSKINSKY, D. K., NASEEM, M., ABDELMOHSEN, U. R., PLICKERT, N., ENGELKE, T., GRIEBEL, T., ZEIER, J., NOVÁK, Ondřej, STRNAD, Miroslav, PFEIFHOFER, H., VAN DER GRAAFF, E., SIMON, U., ROITSCH, T. Cytokinins mediate resistance against Pseudomonas syringae in tobacco through increased antimicrobial phytoalexin synthesis independent of salicylic acid signaling. Plant Physiology. 2011, 157(2), 815-830. ISSN 0032-0889. E-ISSN 1532-2548

Cytokinins are phytohormones that are involved in various regulatory processes throughout plant development, but they are also produced by pathogens and known to modulate plant immunity. A novel transgenic approach enabling autoregulated cytokinin synthesis in response to pathogen infection showed that cytokinins mediate enhanced resistance against the virulent hemibiotrophic pathogen Pseudomonas syringae pv tabaci. This was confirmed by two additional independent transgenic approaches to increase endogenous cytokinin production and by exogenous supply of adenine-and phenylurea-derived cytokinins. The cytokinin-mediated resistance strongly correlated with an increased level of bactericidal activities and up-regulated synthesis of the two major antimicrobial phytoalexins in tobacco (Nicotiana tabacum), scopoletin and capsidiol.