Histochemical aspects of wheat resistance to leaf blast mediated by silicon

Abstract

Blast, caused by Pyricularia oryzae, has become a significant disease threat to wheat (Triticum aestivum L.) in Brazil. This study aimed to investigate at the histochemical level if silicon (Si) could enhance the production of flavonoids in the leaves of wheat plants in response to P. oryzae infection. Plants from the Aliança cultivar, which are susceptible to blast, were grown in hydroponic cultures containing 0 (-Si) or 2 mM of Si (+Si) and inoculated by spraying a conidial suspension of P. oryzae (1 × 10 5 conidia mL ). This increased Si concentration was correlated with reduced fungal growth inside the epidermal cells and the development of blast symptoms on leaves. Strong fluorescence, which is an indication of the presence of flavonoids, was detected in the leaf cells of +Si plants usingNeu's and Wilson's reagents. A novel item of evidence is that, at the histochemical level, Si is involved in the potentiation of the biosynthetic pathway of flavonoids that increases wheat resistance to blast.

Wheat blast research: Status and imperatives

“…They also observed that expression of all defence related genes was significantly increased on infection but expression level was two to three times higher for +Si plants as compared to -Si counterparts. Similar results of increased Si concentration causing reduced fungal growth were reported by Silva et al (2015). They found that at histochemical level, Si is involved in the potentiation of the biosynthetic pathway of flavonoids that increases wheat resistance to blast.…”

“…Ever since its first report, blast pathogen was variously named by researchers for example, Pyricularia oryzae Oliveira et al, 2015;Cruz et al, 2015a;Silva et al, 2015), Pyricularia grisea (Filha et al, 2011;Kohli et al, 2011;Rocha et al, 2014), Magnaporthe grisea (Urashima and Kato, 1994;Peng et al, 2011;Pagani et al, 2014) and M. oryzae Triticum (Cruz et al, 2015a). Blast pathogen has shown capability to evolve fast to adapt to new climates.…”

Association of the Production of Phenylpropanoid Compounds at the Infection Sites of Corynespora cassiicola with Soybean Resistance against Target Spot

“…; Silva et al. ). Leaf sections from non‐inoculated plants for both cultivars were also collected and preserved to serve as the control treatment.…”

“…() and Silva et al. () with a few modifications. Briefly, approximately 30–40 transverse sections (10–30 μ m thick) per petiole and leaf samples were obtained from non‐inoculated and infected leaf sections from plants of each cultivar using a table microtome (model LPC; Rolemberg and Bhering Commercial and Importation LTDA, Belo Horizonte, Brazil).…”

“…; Silva et al. ). Germinated conidia of Colletotrichum gloeosporioides showed different patterns of appressoria formation and germ tube growth on the leaves of apple cultivars that differed in their levels of resistance to Glomerella leaf spot (Araujo et al.…”