Borhan, M.H. and Gunn, N and Cooper, A and Gulden, S and Tör, M and Rimmer, S.R. and Holub, E.B. (2008) WRR4 Encodes a TIR-NB-LRR Protein That Confers Broad-Spectrum White Rust Resistance in Arabidopsis thaliana to Four Physiological Races of Albugo candida. Molecular Plant-Microbe Interactions, 21 (6). pp. 757-768. ISSN 0894-0282Full text not available from this repository. (Request a copy)
White blister rust in the Brassicaceae is emerging as a superb model for exploring how plant biodiversity has channeled speciation of biotrophic parasites. The causal agents of white rust across a wide breadth of cruciferous hosts currently are named as variants of a single oomycete species, Albugo candida. The most notable examples include a major group of physiological races that each are economically destructive in a different vegetable or oilseed crop of Brassica juncea (A. candida race 2), B. rapa (race 7), or B. oleracea (race 9); or parasitic on wild crucifers such as Capsella bursa-pastoris (race 4). Arabidopsis thaliana is innately immune to these races of A. candida under natural conditions; however, it commonly hosts its own molecularly distinct subspecies of A. candida (A. candida subsp. arabidopsis). In the laboratory, we have identified several accessions of Arabidopsis thaliana (e.g.,. Ws-3) that can permit varying degrees of rust development following inoculation with A. candida races 2, 4, and 7, whereas race 9 is universally incompatible in Arabidopsis thaliana and nonrusting resistance is the most prevalent outcome of interactions with the other races. Subtle variation in resistance phenotypes is evident, observed initially with an isolate of A. candida race 4, indicating additional genetic variation. Therefore, we used the race 4 isolate for mapbased cloning of the first of many expected white rust resistance (WRR) genes. This gene was designated WRR4 and encodes a cytoplasmic toll-interleukin receptor-like nucleotide-binding leucine-rich repeat receptor-like protein that confers a dominant, broad-spectrum white rust resistance in the Arabidopsis thaliana accession Columbia to representative isolates of A. candida races 2, 4, 7, and 9, as verified by transgenic expression of the Columbia allele in Ws-3. The WRR4 protein requires functional expression of the lipase-like protein EDS1 but not the paralogous protein PAD4, and confers full immunity that masks an underlying nonhypersensitive incompatibility in Columbia to A. candida race 4. This residual compatibility is independent of functional EDS1.
This is an Open Access article. The full-text can be accessed via the Official URL.
|Uncontrolled Keywords:||basidiomycete, gene-for-gene, innate immunity, Leptosphaeria, natural variation, nonhost, RB, Bs2, RLM1, sid2, molecular biology, plant-pathogen interactions|
|Subjects:||Q Science > QK Botany
Q Science > QR Microbiology > QR355 Virology
Q Science > QH Natural history > QH426 Genetics
Q Science > QH Natural history > QH301 Biology
Q Science > QR Microbiology
|Divisions:||Academic Departments > Institute of Science and the Environment
Research Centres > National Pollen and Aerobiology Research Unit
|Depositing User:||Janet Davidson|
|Date Deposited:||19 Jan 2011 19:37|
|Last Modified:||08 Oct 2013 12:53|
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