Nonhost and basal resistance: how to explain specificity?
Nonhost resistance to plant pathogens can be constitutive or induced by microbes. Successful pathogens suppress microbe-induced plant defences by delivering appropriate effectors, which are apparently not sufficiently effective on nonhost plant species, as can be concluded from the strong host specificity of many biotroph plant pathogens. Such effectors act on particular plant targets, such as promoters or motifs in expressed sequences. Despite much progress in the elucidation of the molecular aspects of nonhost resistance to plant pathogens, very little is known about the genes that determine whether effectors can or cannot suppress the basal defence. In hosts they can, in nonhosts they cannot. The targets determining the host status of plants can be identified in inheritance studies. Recent reports have indicated that nonhost resistance is inherited polygenically, and exhibits strong similarity and association with the basal resistance of plants to adapted pathogens.
Niks
Rients E
RE
Laboratory of Plant Breeding, Wageningen University, PO Box 386, 6700 AJ Wageningen, The Netherlands.
Marcel
Thierry C
TC
Laboratory of Plant Breeding, Wageningen University, PO Box 386, 6700 AJ Wageningen, The Netherlands.
D017343:Genes, Plant / Q000235:genetics; D058507:Host Specificity / Q000235:genetics / Q000276:immunology*; D054884:Host-Pathogen Interactions / Q000235:genetics; D007113:Immunity, Innate / Q000235:genetics; D040582:Inheritance Patterns / Q000235:genetics; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology