Central role of Methyl jasmonate in resistance of wheat against crown and root rot caused by Fusarium culmorum

The Fusarium crown and root rot pathogen Fusarium culmorum (Fc) is a hemibiotrophic pathogen, with a short biotrophic phase preceding necrotrophic life-style. In this study, for the first time, a comparative proteomic analysis was made in seedling roots of two wheat cultivars Falat (susceptible) and Sumai3 (resistant) subjected to Methyl jasmonate (MeJA) at 2 days post Fc-inoculation (2 dpi) to understand defense responses induced by treatment during the necrotrophic stage. Using a high-resolution 2-D gel, a total of 176 proteins were identified at 48 h after MeJA treatment. Among the 176 matched spots, the expression abundances (vol%) of 30 protein spots were changed more than 2-fold (p < 0.05), and thus were treated as differentially expressed proteins (DEPs). Most DEPs from both cultivars were assigned to the 4 categories: metabolic process, energy, defense, and cell structure. Along with the increased resistance induced by MeJA during the later stage of infection which leads to decrease in disease index of both cultivars particularly much greater in susceptible cv. Falat, we observed increased accumulation of isocitrate dehydrogenase, malate dehydrogenase, enolase, glyceraldehyde-3-phosphate dehydrogenase, lipoxygenase (LOX), ATP synthase, peroxidase and L-ascorbate peroxidase compared to untreated Fc-inoculated control in both cultivars. Moreover, the photosynthesis responsive DEPs like RuBisCO down-regulated, to adjust the metabolic status and reserve energy to confront the pathogen attack. Consequently, the soil application of MeJA could be one of a suitable and healthier solution in integrated management to decease the incidence of Fc-infection by triggering plant defense responses via octadecanoid pathway.