White rot caused by Sclerotinia sclerotiorum (SS) is one of the most devastating plant diseases of sunflower. Controlling this pathogen by available tools hardly result in acceptable control. The aim of this study was to elucidate the effects of plant resistance inducers, BTH (benzothiadiazole in Bion 50 WG) and arbuscular mycorrhizal fungi (AMF) on disease development of white rot in three sunflower genotypes. Defence responses were characterized by measuring the disease severity and identifying cellular/histological reactions (e.g. autofluorescence) of host plants upon infection. Depending on the host genotype, a single application of inducers reduced disease symptoms. Histological examination of host responses revealed that BTH and/or AMF pre-treatments significantly impeded the development of pathogenic hyphae in Iregi szürke csíkos and P63LE13 sunflower plants and it was associated with intensive autofluorescence of cells. Both localized and systemic induction of resistance was observed. Importantly, the frequency of mycorrhization of hybrid P63LE13 and PR64H41 was significantly increased upon BTH treatment, so it had a positive effect on the formation of plant-mycorrhiza interactions in sunflower. To our knowledge, this is the first report on the additive effect of BTH on mycorrhization and the positive effect of these inducers against SS in sunflower.
Aysan, E., Demir, S. (2009) Using arbuscular mycorrhizal fungi and Rhizobium leguminosarum Biovar phaseoli against Sclerotinia sclerotiorum (Lib.) de Bary in the common bean (Phaseolus vulgaris L.). Plant Pathol. J. 8, 74–78.
Azcón-Aguilar, C., Barea, J. M. (1996) Arbuscular mycorrhizas and biological control of soil-borne plant pathogens –an overview of the mechanisms involved. Mycorrhiza 6, 457–464.
Bán, R., Virányi, F., Komjáti, H. (2004) Benzothiadiazole-induced resistance to Plasmopara halstedii (Farl.) Berl. et de Toni in sunflower. In: Spencer-Phillips, P. T. N (ed.) Advances in downy mildew research. Kluwer Academic Publishers, Dordrecht, pp. 265–273.
Barilli, E., Prats, E., Rubiales, D. (2010) Benzothiadiazole and BABA improve resistance to Uromyces pisi (Pers.) Wint. in Pisum sativum L. with an enhancement of enzymatic activities and total phenolic content. Eur. J. Plant Pathol. 128, 483–493.
Buzi, A., Chilosi, G., De Sillo, D., Magro, P. (2004) Induction of resistance in melon to Didymella bryoniae and Sclerotinia sclerotiorum by seed treatments with acibenzolar-S-methyl and methyl jasmonate but not with salicylic acid. J. Phytopath. 152, 34–42.
Chandrashekara, C. P., Patil, V. C., Sreenivasa, M. N. (1995) Response of two sunflower (Helianthus annuus L.) genotypes to VA-mycorrhizal inoculation and phosphorus levels. Biotropia 8, 53–59.
Cordier, C., Pozo, M. J., Barea, J. M., Gianinazzi, S., Gianinazzi-Pearson, V. (1998) Cell defense responses associated with localized and systemic resistance to Phytophthora parasitica induced in tomato by an arbuscular mycorrhizal fungus. Mol. Plant Microbe Int. 11, 1017–1028.
Dann, E., Diers, B., Byrum, J., Hammerschmidt, R. (1998) Effect of treating soybean with 2,6-dichloroisonicotinic acid (INA) and benzothiadiazole (BTH) on seed yields and the level of disease caused by Sclerotinia sclerotiorum in field and greenhouse studies. Eur. J. Plant Pathol. 104, 271–278.
Ezzat, A. S., Ghoneem, K. M., Saber, W. I. A., Al-Askar, A. A. (2015) Control of wilt, stalk and tuber rots diseases using arbuscular mycorrhizal fungi, Trichoderma species and hydroquinone enhances yield quality and storability of Jerusalem artichoke (Helianthus tuberosus L.). Egypt. Journ. Biol. Pest Cont. 25, 11–22.
Faessel, L., Nassr, N., Lebeau, T., Walter, B. (2010) Chemically-induced resistance on soybean inhibits nodulation and mycorrhization. Plant Soil 329, 259–268.
Görlach, J., Volrath, S., Knauf-Beiter, G., Hengy, G., Beckhove, U., Kogel, K.-H., Oostendorp, M., Staub, T., Ward, E., Kessmann, H., Ryals, J. (1996) Benzothiadiazole, a novel class of inducers of systemic acquired resistance, activates gene expression and disease resistance in wheat. The Plant Cell 8, 629–643.
Harrach, B. D., Baltruschat, H., Barna, B., Fodor, J., Kogel, K.-H. (2013) The mutualistic fungus Piriformospora indica protects barley roots from a loss of antioxidant capacity caused by the necrotrophic pathogen Fusarium culmorum. Mol. Plant-Microbe Int. 26, 599–605.
Koornneef, A., Pieterse, C. M. J. (2008) Cross talk in defense signaling. Plant Physiol. 146, 839–844.
Körösi, K., Bán, R., Barna, B., Virányi, F. (2011) Biochemical and molecular changes in downy mildew-infected sunflower triggered by resistance inducers. J. Phytopath. 159, 471–478.
Mur, A. J., Kenton, P., Atzorn, R., Miersch, O., Wasternack, C. (2006) The outcomes of concentrationspecific interactions between salicylate and jasmonate signaling include synergy, antagonism, and oxidative stress leading to cell death. Plant Physiol. 140, 249–262.
MYCOCALC software package (2001) Retrieved from http://www2.dijon.inra.fr/mychintec/ Mycocalc-prg/download.html.
Oostendorp, M., Kunz, W., Dietrich, B., Staub, T. (2001) Induced disease resistance in plants by chemicals. Eur. J. Plant Pathol. 107, 19–28.
Özgönen, H., Bicici, M., Erkilic, A. (2001) The effect of salicyclic acid and endomycorrhizal fungus Glomus etunicatum on plant development of tomatoes and fusarium wilt caused by Fusarium oxysporum f. sp lycopersici. Turk. J. Agric. For. 25, 25–29.
Pozo, M. J., Azcon-Aguilar, C. (2007) Unraveling mycorrhiza-induced resistance. Cur. Op. in Plant Biol. 10, 393–398.
Prats, E., Rubiales, D., Jorrin, J. (2002) Acibenzolar-S-methyl-induced resistance to sunflower rust (Puccinia helianthi) is associated with an enhancement of coumarins on foliar surface. Physiol. Mol. Plant Pathol. 60, 155–162.
Rodríguez, M. A., Venedikian, N., Bazzalo, M. E., Godeas, A. (2004) Histopathology of Sclerotinia sclerotiorum attack on flower parts of Helianthus annuus heads in tolerant and susceptible varieties. Mycopathologia 157, 291–302.
Ryals, J., Uknes, S., Ward, E. (1994) Systemic acquired resistance. Plant Physiol. 104, 1109–1112.
Saharan, G. S., Mehta, N. (2008) Sclerotinia diseases of crop plants: biology, ecology and disease management. Springer Science+Business Media B.V.
Tosi, L., Luigetti, L., Zazzerini, A. (1999) Benzothiadiazole induces resistance to Plasmopara helianthi in sunflower plants. J. Phytopath. 147, 365–370.
Tosi, L., Zazzerini, A. (2000) Interactions between Plasmopara helianthi, Glomus mosseae and two plant activators in sunflower plants. Eur. J. Plant Pathol. 106, 735–744.
Trouvelot, A., Kough, J. L., Gianinazzi-Pearson, V. (1986) Mesure du taux de mycorhization VA d’un système radiculaire. Recherche de méthodes d’estimation ayant une signification fonctionnelle. In: Gianinazzi-Pearson, V., Gianinazzi, S. (eds) Physiological and Genetical Aspects of Mycorrhizae. Paris. INRA Press, pp. 217–221.
Vierheilig, H., Steinkellner, S., Khaosaad, T., Garcia-Garrido, J. M. (2008) The biocontrol effect of mycorrhization on soilborne fungal pathogens and the autoregulation of the AM symbiosis: One mechanism, two effects? In: Varma, A. (ed.) Mycorrhiza. Berlin Heidelberg, Springer-Verlag, pp. 307–320.
Walters, D. R., Ratsep, J., Havis, N. D. (2013) Controlling crop diseases using induced resistance: challenges for the future. J. Exp. Bot. 64, 1263–1280.