title: Non-host Plant Resistance againstPhytophthora capsiciIs Mediated in Part by Members of theI2 RGene Family inNicotianaspp.
abstract: The identification of host genes associated with resistance toPhytophthora capsiciis crucial to developing strategies of control against this oomycete pathogen. Since there are few sources of resistance toP. capsiciin crop plants, non-host plants represent a promising source of resistance genes as well as excellent models to studyP. capsici- plant interactions. We have previously shown that non-host resistance toP. capsiciinNicotianaspp. is mediated by the recognition of a specificP. capsicieffector protein, PcAvr3a1 in a manner that suggests the involvement of a cognate disease resistance (R) genes. Here, we have used virus-induced gene silencing (VIGS) and transgenic tobacco plants expressing dsRNA inNicotianaspp. to identify candidateRgenes that mediate non-host resistance toP. capsici. Silencing of members of theI2multigene family in the partially resistant plantN. edwardsoniiand in the resistantN. tabacumresulted in compromised resistance toP. capsici. VIGS of two other components required forRgene-mediated resistance,EDS1andSGT1, also enhanced susceptibility toP. capsiciinN. edwardsonii, as well as in the susceptible plantsN. benthamianaandN. clevelandii. The silencing ofI2family members inN. tabacumalso compromised the recognition of PcAvr3a1. These results indicate that in this case, non-host resistance is mediated by the same components normally associated with race-specific resistance.
authors.affiliation: Boyce Thompson Institute for Plant Research, IthacaNY, USA; Laboratorio de Ciencias Agrogenómicas, Escuela Nacional de Estudios Superiores - León, Universidad Nacional Autónoma de MexicoLeón, Mexico.
authors.forename: Julio C
authors.initials: JC
authors.lastname: Vega-Arreguín
authors.affiliation: Laboratorio de Ciencias Agrogenómicas, Escuela Nacional de Estudios Superiores - León, Universidad Nacional Autónoma de Mexico León, Mexico.
authors.forename: Harumi
authors.initials: H
authors.lastname: Shimada-Beltrán
authors.affiliation: Laboratorio de Ciencias Agrogenómicas, Escuela Nacional de Estudios Superiores - León, Universidad Nacional Autónoma de Mexico León, Mexico.
authors.forename: Jacobo
authors.initials: J
authors.lastname: Sevillano-Serrano
authors.affiliation: Boyce Thompson Institute for Plant Research, IthacaNY, USA; Département de Biologie, Faculté des Sciences, Université de Sherbrooke, SherbrookeQC, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Moffett
keywords: Nicotiana; Phytophthora capsici; R gene; hypersensitive response; non-host resistance