In spite of the enormous information from research on genetics of plant disease resistance, the question still remains unresolved: what is directly inhibiting or killing pathogens and suppressing symptoms in resistant plants? This is particularly true for resistance to viral infections. Here we show that externally applied reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) or ROS-producing (O 2·− [superoxide] and H2O2) chemical systems infiltrated into tobacco leaves 2 hours after inoculation suppress replication of Tobacco mosaicvirus (TMV) in the susceptible Samsun (nn) cultivar. This was determined by a biological and a real-time PCR method. Infiltration of leaves of the resistant Xanthi (NN) cultivar with the ROS-producing chemicals and H2O2 significantly suppressed local necrotic lesions (i.e. the hypersensitive response) after inoculation of tobacco leaves with TMV. Accordingly, an early accumulation or external application of ROS, such as O 2·− and H2O2, in tobacco may contribute to the development of resistance to TMV infection.
Abramovitch, R. B., Anderson, J. C. and Martin, G. B. (2006): Bacterial elicitation and evasion of plant innate immunity. Nat. Rev. Molec. Cell Biol. 7, 601–611.
Martin G. B. , 'Bacterial elicitation and evasion of plant innate immunity ' (2006 ) 7 Nat. Rev. Molec. Cell Biol. : 601 -611.
Apel, K. and Hirt, H. (2004): Reactive oxygen species: metabolism, oxidative stress and signal transduction. Annu. Rev. Plant Biol. 55, 373–399.
Hirt H. , 'Reactive oxygen species: metabolism, oxidative stress and signal transduction ' (2004 ) 55 Annu. Rev. Plant Biol. : 373 -399.
Ausubel, F. M. (2005): An innate immune signaling pathways in plants and animals conserved? Nat. Immunol. 6, 973–979.
Ausubel F. M. , 'An innate immune signaling pathways in plants and animals conserved? ' (2005 ) 6 Nat. Immunol. : 973 -979.
Ádám, A., Farkas, T., Somlyai, G., Hevesi, M. and Király, Z. (1989): Consequence of O2 ·− generation during a bacterially induced hypersensitive reaction in tobacco: deterioration of membrane lipids. Physiol.Molec. Plant Pathol. 34, 13–26.
Király Z. , 'Consequence of O2·− generation during a bacterially induced hypersensitive reaction in tobacco: deterioration of membrane lipids ' (1989 ) 34 Physiol.Molec. Plant Pathol. : 13 -26.
Baker, J. C. and Orlandi, E.W. (1995):Active oxygen in plant pathogenesis. Annu. Rev. Phytopathol. 33, 299–321.
Orlandi E.W. , 'oxygen in plant pathogenesis ' (1995 ) 33 Annu. Rev. Phytopathol. : 299 -321.
Bendahmane, A., Kanyuka, K. and Baulcombe, D. C. (1999): The Rx gene from potato controls separate virus resistance and death responses. Plant Cell 11, 781–791.
Baulcombe D. C. , 'The Rx gene from potato controls separate virus resistance and death responses ' (1999 ) 11 Plant Cell : 781 -791.
Büschges, R., Hollricher, K. Panstruga, R. et al. (1997): The barley Mlo gene: a novel control element of plant pathogen resistance. Cell 88, 695–705.
Panstruga R. , 'The barley Mlo gene: a novel control element of plant pathogen resistance ' (1997 ) 88 Cell : 695 -705.
Covey, S. N., Al-Kaff, N. S., Langare, A. and Turner, D. S. (1997): Plants combat infection by gene silencing. Nature 85, 780–781.
Turner D. S. , 'Plants combat infection by gene silencing ' (1997 ) 85 Nature : 780 -781.
Doke, N. (1983): Involvement of a superoxide anion generation in the hypersensitive response of potato tuber tissues to infection with an incompatible race of Phytophthora infestans and to the hyphal wall components. Physiol. Plant Pathol. 23, 345–357.
Doke N. , 'Involvement of a superoxide anion generation in the hypersensitive response of potato tuber tissues to infection with an incompatible race of Phytophthora infestans and to the hyphal wall components ' (1983 ) 23 Physiol. Plant Pathol. : 345 -357.
Doke, N. and Ohashi, Y. (1988): Involvement of an O2 ·− generating system in the induction of necrotic lesions on tobacco leaves infected with Tobacco mosaic virus. Physiol. Molec. Plant Pathol. 32, 163–175.
Ohashi Y. , 'Involvement of an O2·− generating system in the induction of necrotic lesions on tobacco leaves infected with Tobacco mosaic virus ' (1988 ) 32 Physiol. Molec. Plant Pathol. : 163 -175.
Dorey, S., Baillieul, F., Saindrenan, P., Fritig, B. and Kaufmann, S. (1998): Tobacco class I and II catalases are differentially expressed during elicitor-induced hypersensitive cell death and localized acquired resistance. Mol. Plant-Microbe Interact. 11, 1102–1109.
Kaufmann S. , 'Tobacco class I and II catalases are differentially expressed during elicitor-induced hypersensitive cell death and localized acquired resistance ' (1998 ) 11 Mol. Plant-Microbe Interact. : 1102 -1109.
Hafez, Y. M. and Király, Z. (2003): Role of hydrogen peroxide in symptom expression of barley susceptible and resistant to powdery mildew. Acta Phytopathol. Entomol. Hung. 38, 227–236.
Király Z. , 'Role of hydrogen peroxide in symptom expression of barley susceptible and resistant to powdery mildew ' (2003 ) 38 Acta Phytopathol. Entomol. Hung. : 227 -236.
Holmes, F. O. (1938): Inheritance of resistance to tobacco mosaic virus disease in tobacco. Phytopathology 28, 553–561.
Holmes F. O. , 'Inheritance of resistance to tobacco mosaic virus disease in tobacco ' (1938 ) 28 Phytopathology : 553 -561.
Höller, K., Király, L., Künstler, A., Müller, M., Gullner, G., Fattinger, M. and Zechmann, B. (2010): Enhanced glutathione metabolism is correlated with sulfur induced resistance in Tobacco mosaic virus-infected genetically susceptible Nicotiana tabacum plants. Mol. Plant-Microbe Interact. 23, 1448–1459.
Zechmann B. , 'Enhanced glutathione metabolism is correlated with sulfur induced resistance in Tobacco mosaic virus-infected genetically susceptible Nicotiana tabacum plants ' (2010 ) 23 Mol. Plant-Microbe Interact. : 1448 -1459.
Jordan, C.M., Wakeman, R. J. and DeVay, J. E. (1992): Toxicity of free riboflavine and methionine riboflavin solutions to Phytophthora infestans and the reduction of potato late blight disease. Canad. J. Microbiol. 38, 1108–1111.
DeVay J. E. , 'Toxicity of free riboflavine and methionine riboflavin solutions to Phytophthora infestans and the reduction of potato late blight disease ' (1992 ) 38 Canad. J. Microbiol. : 1108 -1111.
Király, L., Barna, B. and Király, Z. (2007): Plant resistance to pathogen infection: Forms and mechanisms of innate and acquired resistance. J. Phytopathol. 155, 385–396.
Király Z. , 'Plant resistance to pathogen infection: Forms and mechanisms of innate and acquired resistance ' (2007 ) 155 J. Phytopathol. : 385 -396.
Király, L., Hafez, Y. M., Fodor, J. and Király, Z. (2008): Suppression of tobacco mosaic virus-induced hypersensitive-type necrotisation in tobacco at high temperature is associated with down-regulation of NADPH oxidase and superoxide and stimulation of dehydroascorbate reductase. J. Gen. Virol. 89, 799–808.
Király Z. , 'Suppression of tobacco mosaic virus-induced hypersensitive-type necrotisation in tobacco at high temperature is associated with down-regulation of NADPH oxidase and superoxide and stimulation of dehydroascorbate reductase ' (2008 ) 89 J. Gen. Virol. : 799 -808.
Király, Z., Barna, B. and Érsek, T. (1972): Hypersensitivity as a consequence, not the cause, of plant disease resistance to infection. Nature 239, 215–219.
Érsek T. , 'Hypersensitivity as a consequence, not the cause, of plant disease resistance to infection ' (1972 ) 239 Nature : 215 -219.
Király, Z., El-Zahaby, H., Galal, A., Abdou, S., Ádám, A., Barna, B. and Klement, Z. (1993): Effect of oxy free radicals on plant pathogenic bacteria and fungi and on some plant diseases. In: G. Mózsik et al. (eds): Oxygen Free Radicals and Scavengers in the Natural Sciences, Akadémiai Kiadó, Budapest, pp. 9–19.
Klement Z. , '', in Oxygen Free Radicals and Scavengers in the Natural Sciences , (1993 ) -.
Levine, A., Tenhaken, R., Dixon, R. and Lamb, C. (1994): H2O2 from the oxidative burst orchestrates the plant hypersensitive disease resistance response. Cell 79, 583–593.
Lamb C. , 'H2O2 from the oxidative burst orchestrates the plant hypersensitive disease resistance response ' (1994 ) 79 Cell : 583 -593.
Otulak, K. and Garbaczewska, G. (2010): Localisation of hydrogen peroxide accumulation during Solanum tuberosum cv. Rywal hypersensitive response to Potato virus Y. Micron 41, 327–335.
Garbaczewska G. , 'Localisation of hydrogen peroxide accumulation during Solanum tuberosum cv. Rywal hypersensitive response to Potato virus Y ' (2010 ) 41 Micron : 327 -335.
Ratcliff, F., Harrison, B. D. and Baulcombe, D. C. (1997): A similarity between viral defense and gene silencing in plants. Science 276, 1558–1560.
Baulcombe D. C. , 'A similarity between viral defense and gene silencing in plants ' (1997 ) 276 Science : 1558 -1560.
Schulze-Lefert, P. and Bieri, S. (2005): Recognition at a distance. Science 308, 506–508.
Bieri S. , 'Recognition at a distance ' (2005 ) 308 Science : 506 -508.
Shang, J., Xi, D.-H., Yuan, S. et al. (2010): Difference of physiological characters in dark green islands and yellow leaf tissue of Cucumber mosaic virus (CMV)-infected Nicotiana tabacum leaves. Z. Naturforsch. 65c, 73–78.
Yuan S. , 'Difference of physiological characters in dark green islands and yellow leaf tissue of Cucumber mosaic virus (CMV)-infected Nicotiana tabacum leaves ' (2010 ) 65c Z. Naturforsch. : 73 -78.
Staskawicz, B. J., Ausubel, F. F., Baker, B. J., Ellis, J. G. and Jones, J. D. G. (1995): Molecular genetics of plant disease resistance. Science 268, 661–667.
Jones J. D. G. , 'Molecular genetics of plant disease resistance ' (1995 ) 268 Science : 661 -667.
Talarczyk, A., Krzymowska, M., Borucki, W. and Hennig, J. (2002): Effect of yeast CTA1 gene expression on response of tobacco plants to tobacco mosaic virus infection. Plant Physiol. 129, 1032–1044.
Hennig J. , 'Effect of yeast CTA1 gene expression on response of tobacco plants to tobacco mosaic virus infection ' (2002 ) 129 Plant Physiol. : 1032 -1044.
Torres, M.A., Jones, J. D. G. and Dangl, J. L. (2006): Reactive oxygen species signaling in response to pathogens. Plant Physiol. 141, 373–378.
Dangl J. L. , 'Reactive oxygen species signaling in response to pathogens ' (2006 ) 141 Plant Physiol. : 373 -378.
Tzeng, D. D. and DeVay, J. E. (1993): Role of oxygen radicals in plant disease development. In: J. H. Andrews and I. C. Tommerup (eds): Advances in Plant Pathology. Vol. 10. Academic Press, London, pp. 1–34.
DeVay J. E. , '', in Advances in Plant Pathology , (1993 ) -.
Waterhouse, P. M., Smith, N. A. and Wang, M. B. (1999): Virus resistance and gene silencing: killing the messenger. Trends Plant Sci. 4, 452–457.
Wang M. B. , 'Virus resistance and gene silencing: killing the messenger ' (1999 ) 4 Trends Plant Sci. : 452 -457.
Whitham, S., Dinesh-Kumar, S. P., Choi, D., Hehl, R., Corr, C. and Baker, B. (1994): The product of the tobacco mosaic virus resistance gene N: similarity to Toll and the interleukin-1 receptor. Cell 78, 1101–1115.
Baker B. , 'The product of the tobacco mosaic virus resistance gene N: similarity to Toll and the interleukin-1 receptor ' (1994 ) 78 Cell : 1101 -1115.
Wu, Shortt, B. J., Lawrence, E. B., Leon, J., Fitzsimmons, K. C., Levine, R. B., Raskin, I. and Shah, D.M. (1997): Activation of host defence mechanisms by elevated production of H2O2 in transgenic plants. Plant Physiol. 115, 427–435.
Shah D.M. , 'Activation of host defence mechanisms by elevated production of H2O2 in transgenic plants ' (1997 ) 115 Plant Physiol. : 427 -435.
Yi, S.Y., Yu, S. H. and Choi, D. (1999): Molecular cloning of a catalase cDNA from Nicotiana glutinosa L. and its repression by tobacco mosaic virus infection. Mol. Cells 9, 320–325.
Choi D. , 'Molecular cloning of a catalase cDNA from Nicotiana glutinosa L. and its repression by tobacco mosaic virus infection ' (1999 ) 9 Mol. Cells : 320 -325.
Yi, S.Y., Yu, S. H. and Choi, D. (2003): Involvement of hydrogen peroxide in repression of catalase in TMV-infected resistant tobacco. Mol. Cells 15, 364–369.
Choi D. , 'Involvement of hydrogen peroxide in repression of catalase in TMV-infected resistant tobacco ' (2003 ) 15 Mol. Cells : 364 -369.
Yoda, H., Yamaguchi, Y. and Sano, H. (2003): Induction of hypersensitive cell death by hydrogen peroxide produced through polyamine degradation in tobacco plants. Plant Physiol. 132, 1973–1981.
Sano H. , 'Induction of hypersensitive cell death by hydrogen peroxide produced through polyamine degradation in tobacco plants ' (2003 ) 132 Plant Physiol. : 1973 -1981.