Silicon induces resistance to the brown spot fungus Cochliobolus miyabeanus by preventing the pathogen from hijacking the rice ethylene pathway

0446665 - ÚEB 2016 RIV GB eng J - Journal Article
Van Bockhaven, J. - Spíchal, L. - Novák, Ondřej - Strnad, Miroslav - Asano, T. - Kikuchi, S. - Hofte, M. - De Vleesschauwer, D.
Silicon induces resistance to the brown spot fungus Cochliobolus miyabeanus by preventing the pathogen from hijacking the rice ethylene pathway.
New Phytologist. Roč. 206, č. 2 (2015), s. 761-773. ISSN 0028-646X. E-ISSN 1469-8137
R&D Projects: GA MŠMT(CZ) LO1204
Institutional support: RVO:61389030
Keywords : Bipolaris oryzae * Cochliobolus miyabeanus * disease resistance
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 7.210, year: 2015

Although numerous studies have shown the ability of silicon (Si) to mitigate a wide variety of abiotic and biotic stresses, relatively little is known about the underlying mechanism(s). Here, we have investigated the role of hormone defense pathways in Si-induced resistance to the rice brown spot fungus Cochliobolus miyabeanus. To delineate the involvement of multiple hormone pathways, a multidisciplinary approach was pursued, combining exogenous hormone applications, pharmacological inhibitor experiments, time-resolved hormone measurements, and bioassays with hormone-deficient and/or -insensitive mutant lines. Contrary to other types of induced resistance, we found Si-induced brown spot resistance to function independently of the classic immune hormones salicylic acid and jasmonic acid. Our data also rule out a major role of the abscisic acid (ABA) and cytokinin pathways, but suggest that Si mounts resistance to C.miyabeanus by preventing the fungus from hijacking the rice ethylene (ET) machinery. Interestingly, rather than suppressing rice ET signaling per se, Si probably interferes with the production and/or action of fungal ET. Together our findings favor a scenario whereby Si induces brown spot resistance by disarming fungal ET and argue that impairment of pathogen virulence factors is a core resistance mechanism underpinning Si-induced plant immunity.
Permanent Link: http://hdl.handle.net/11104/0248642