Stagonospora nodorum blotch (SNB) is an\ud important wheat disease caused by Parastagonospora\ud nodorum (Berk.) Studies in Mycology, 75: 307–390\ud (2013). This necrotrophic pathogen can attack common\ud and durum wheat, causing grain yield, quality and safety\ud worsening. This work aims to studying a novel diagnostic\ud technique for early detecting P. nodorum attack and\ud infection progression in three Italian commercial varieties\ud of durum wheat. Plants of these wheat varieties were\ud inoculated in field with a spore suspension of\ud P. nodorum. Different experimental conditions were\ud used: P. nodorum was inoculated in plants at different\ud growth stage (GS); GS32 (Inf A) and GS 73 (milk\ud development - Inf B). To consider natural contaminating\ud mycoflora interference for the subsequent analysis, noninoculated\ud controls, fungicide-treated (T) or non-treated\ud (NT) were used. Inf A produced symptoms both on\ud leaves and ears which appeared to be more severe compared\ud to those induced by Inf B, even if the latter\ud affected more thoroughly wheat yield in at least one\ud variety of wheat. An early detection of SNB could be\ud helpful to manage a targeted control strategy.\ud Hyperspectral imaging analyses showed that this rapid\ud and non-invasive technique allows differentiation between\ud spectra of healthy and diseased tissues already\ud 48 h after inoculation. qPCR confirmed hyperspectral\ud results. The results showed that marked differences\ud emerge in the ability of the varieties to tolerate the\ud SNB disease especially regarding grain yield and quality.\ud Compared with classical approaches, the\ud hyperspectral imaging analysis may represent a useful\ud tool for early detection of P. nodorum on wheat

The Septoria Leaf Blotch Complex (SLBC), caused by the two ascomycetes Zymoseptoria tritici and Parastagonospora nodorum, can reduce wheat global yearly yield by up to 50%. In the last decade, SLBC incidence has increased in Italy; notably, durum wheat has proven to be more susceptible than common wheat. Field fungicide treatment can efficiently control these pathogens, but it leads to the emergence of resistant strains and adversely affects human and animal health and the environment. Our previous studies indicated that active compounds produced by Trametes versicolor can restrict the growth of mycotoxigenic fungi and the biosynthesis of their secondary metabolites (e.g., mycotoxins). Specifically, we identified Tramesan: a 23 kDa α-heteropolysaccharide secreted by T. versicolor that acts as a pro-antioxidant molecule in animal cells, fungi, and plants. Foliar-spray of Tramesan (3.3 μM) on SLBC-susceptible durum wheat cultivars, before inoculation of causal agents of Stagonospora Nodorum Blotch (SNB) and Septoria Tritici Blotch (STB), significantly decreased disease incidence both in controlled conditions (SNB: −99%, STB: −75%) and field assays (SNB: −25%, STB: −30%). We conducted these tests were conducted under controlled conditions as well as in field. We showed that Tramesan increased the levels of jasmonic acid (JA), a plant defense-related hormone. Tramesan also increased the early expression (24 hours after inoculation—hai) of plant defense genes such as PR4 for SNB infected plants, and RBOH, PR1, and PR9 for STB infected plants. These results suggest that Tramesan protects wheat by eliciting plant defenses, since it has no direct fungicidal activity. In field experiments, the yield of durum wheat plants treated with Tramesan was similar to that of healthy untreated plots. These results encourage the use of Tramesan to protect durum wheat against SLBC.

No abstract

No abstract

No abstract

The Septoria Leaf Blotch Complex (SLBC), caused by the two ascomycetes Zymoseptoria tritici and Parastagonospora nodorum, can reduce global yearly yield of wheat by up to 50%. In the last decade in Italy, SLBC incidence has increased; notably, durum wheat has proven to be more susceptible than common wheat. Field fungicide treatment can efficiently control these pathogens, but it leads to the emergence of resistant strains and adversely affects human and animal health, and the environment. Our previous studies indicated that active compounds produced by Trametes versicolor can restrict the growth of mycotoxigenic fungi and the biosynthesis of their secondary metabolites (e.g. mycotoxins). Specifically, we identified Tramesan: a 23 KDa -heteropolysaccharide secreted by T. versicolor that acts as a pro-antioxidant molecule in animal cells, fungi, and plants. Foliar-spraying of Tramesan (3.3 µM) in SLBC-susceptible varieties of durum significantly diminished symptoms of Stagonospora Nodorum Blotch (SNB) and Septoria Tritici Blotch (STB) by 75% and 65%, respectively. Tests were conducted under controlled conditions as well as in field. We show that Tramesan elicits wheat defence against SNB and STB augmenting the synthesis of defence-related hormones, notably JA and SA, that in turn switch on the expression of markers of defence (PR1, PR4 inter alia). In field experiments, yield of durum wheat plants treated with Tramesan was similar to that of untreated ones. The results suggest the use of Tramesan for protecting durum wheat against SLBC.