title: A molecular evolutionary concept connecting nonhost resistance, pathogen host range, and pathogen speciation.
abstract: Any given pathogenic microbial species typically colonizes a limited number of plant species. Plant species outside of this host range mount nonhost disease resistance to attempted colonization by the, in this case, non-adapted pathogen. The underlying mechanism of nonhost immunity and host immunity involves the same non-self detection systems, the combined action of nucleotide-binding and leucine-rich repeat (NB-LRR) proteins and pattern recognition receptors (PRRs). Here we hypothesize that the relative contribution of NB-LRR- and PRR-triggered immunity to nonhost resistance changes as a function of phylogenetic divergence time between host and nonhost. Similarly, changes in pathogen host range, e.g. host range expansions, appear to be driven by variation in pathogen effector repertoires, in turn leading to reproductive isolation and subsequent pathogen speciation.
authors.affiliation: Max-Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions, Carl-von-Linné-Weg 10, D-50829 Köln, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Schulze-Lefert
authors.forename: Ralph
authors.initials: R
authors.lastname: Panstruga
mesh_terms: D017360:Arabidopsis / Q000276:immunology / Q000382:microbiology; D001419:Bacteria / Q000472:pathogenicity; D019143:Evolution, Molecular; D005658:Fungi / Q000472:pathogenicity; D049810:Genetic Speciation; D058507:Host Specificity / Q000235:genetics*; D000090263:Leucine-Rich Repeat Proteins; D057865:Plant Immunity / Q000235:genetics*; D010944:Plants / Q000276:immunology* / Q000382:microbiology*; D011506:Proteins / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism
chemical_list: D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins; D011971:Receptors, Immunologic