The stem rust resistance gene Rpg5 encodes a protein with nucleotide-binding-site, leucine-rich, and protein kinase domains

Abstract

We isolated the barley stem rust resistance genes Rpg5 and rpg4 by map-based cloning. These genes are colocalized on a 70-kb genomic region that was delimited by recombination. The Rpg5 gene consists of an unusual structure encoding three typical plant disease resistance protein domains: nucleotide-binding site, leucine-rich repeat, and serine threonine protein kinase. The predicted RPG5 protein has two putative transmembrane sites possibly involved in membrane binding. The gene is expressed at low but detectable levels. Posttranscriptional gene silencing using VIGS resulted in a compatible reaction with a normally incompatible stem rust pathogen. Allele sequencing also validated the candidate Rpg5 gene. Allele and recombinant sequencing suggested that the probable rpg4 gene encoded an actin depolymerizing factor-like protein. Involvement of actin depolymerizing factor genes in nonhost resistance has been documented, but discovery of their role in gene-for-gene interaction would be novel and needs to be further substantiated.actin depolymerizing factor ͉ barley ͉ disease resistance domains ͉ map-based cloning

Plant Innate Immunity: Perception of Conserved Microbial Signatures

“…In addition, several structurally related proteins are predicted to be receptors of conserved microbial signatures as they have a confirmed role in (broad-spectrum) disease resistance or are known to bind a conserved microbial signature ( Table 1). The recognition of conserved microbial signatures is most likely not restricted to the apoplastic space because several cytoplasmic non-RD kinases were recently identified as conferring broad-spectrum disease resistance (21,22,71). Clearly, as more genomes (especially monocot genomes) are explored, new receptor variants will be found ( Figure 1, Table 1).…”

A unique wheat disease resistance-like gene governs effector-triggered susceptibility to necrotrophic pathogens

“…Another, albeit smaller, class of R proteins are those composed of serine/threonine protein kinase (S/TPK) domains such as the barley Rpg1 stem rust R gene (3). The barley Rpg5 stem rust R gene represents a unique structure among R genes in that it contains an N-terminal NBS-LRR and a C-terminal S/TPK (4).…”

Durable resistance to the wheat rusts: integrating systems biology and traditional phenotype-based research methods to guide the deployment of resistance genes

“…With the Ug99 family of stem rust races Table 1 The structures of known genes conferring resistance to Puccinia spp. in cereals (Cloutier et al 2007;Brueggeman et al 2008;Fu et al 2009;Krattinger et al 2009;updated Despite the general trend presented here, lack of durability is not exclusively or even necessarily associated with the NBS-LRR forms of resistance genes, as illustrated by the emergence of pathotype Pgt-QCC virulent on the long-deployed barley stem rust resistance gene Rpg1 (a protein kinase) (Martens et al 1989;Jin et al 1994;Brueggeman et al 2002) and the current efficacy of the leaf rust resistance gene Lr21 (an NBS-LRR gene of limited deployment) against all known races of leaf rust (Huang et al 2009) diversifying (Jin et al 2008(Jin et al , 2009), 1 and with nearly 80 races of stripe rust with new virulence patterns appearing in the United States alone since 2000, 2 it is generally agreed that the defeat of major genes is no longer a question of ''if'' but ''when'' and that the need for alternative defense strategies is pressing. Specifically, these recent epidemics have reinvigorated interest within the wheat breeding and research communities in partial resistance genes as sources of potentially more durable resistance.…”