title: Priming of plant resistance by natural compounds. Hexanoic acid as a model.
abstract: Some alternative control strategies of currently emerging plant diseases are based on the use of resistance inducers. This review highlights the recent advances made in the characterization of natural compounds that induce resistance by a priming mechanism. These include vitamins, chitosans, oligogalacturonides, volatile organic compounds, azelaic and pipecolic acid, among others. Overall, other than providing novel disease control strategies that meet environmental regulations, natural priming agents are valuable tools to help unravel the complex mechanisms underlying the induced resistance (IR) phenomenon. The data presented in this review reflect the novel contributions made from studying these natural plant inducers, with special emphasis placed on hexanoic acid (Hx), proposed herein as a model tool for this research field. Hx is a potent natural priming agent of proven efficiency in a wide range of host plants and pathogens. It can early activate broad-spectrum defenses by inducing callose deposition and the salicylic acid (SA) and jasmonic acid (JA) pathways. Later it can prime pathogen-specific responses according to the pathogen's lifestyle. Interestingly, Hx primes redox-related genes to produce an anti-oxidant protective effect, which might be critical for limiting the infection of necrotrophs. Our Hx-IR findings also strongly suggest that it is an attractive tool for the molecular characterization of the plant alarmed state, with the added advantage of it being a natural compound.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universitat de Valencia, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas Valencia, Spain.
authors.forename: Paz
authors.initials: P
authors.lastname: Aranega-Bou
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universitat de Valencia, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas Valencia, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: de la O Leyva
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universitat de Valencia, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas Valencia, Spain.
authors.forename: Ivan
authors.initials: I
authors.lastname: Finiti
authors.affiliation: Grupo de Bioquímica y Biotecnología, Área de Fisiología Vegetal, Departamento de Ciencias Agrarias y del Medio Natural, Escola Superior de Tecnologia i Ciències Experimentals, Universitat Jaume I Castellón, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Agustín
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universitat de Valencia, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas Valencia, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: González-Bosch
keywords: Botrytis cinerea; hexanoic acid; natural inducers; oxidative stress; priming; vitamins