Specific targeting of the Arabidopsis resistance protein RPW8.2 to the interfacial membrane encasing the fungal Haustorium renders broad-spectrum resistance to powdery mildew.

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TitleSpecific targeting of the Arabidopsis resistance protein RPW8.2 to the interfacial membrane encasing the fungal Haustorium renders broad-spectrum resistance to powdery mildew.
Publication TypeJournal Article
Year of Publication2009
AuthorsWang, W, Wen, Y, Berkey, R, Xiao, S
JournalPlant Cell
Volume21
Issue9
Pagination2898-913
Date Published2009 Sep
ISSN1532-298X
KeywordsActins, Arabidopsis, Arabidopsis Proteins, Ascomycota, Cytoskeleton, DNA, Plant, Gene Expression Regulation, Plant, Host-Pathogen Interactions, Hydrogen Peroxide, Immunity, Innate, Molecular Sequence Data, Plant Diseases, Plants, Genetically Modified, Salicylic Acid
Abstract

Powdery mildew fungal pathogens penetrate the plant cell wall and develop a feeding structure called the haustorium to steal photosynthetate from the host cell. Here, we report that the broad-spectrum mildew resistance protein RPW8.2 from Arabidopsis thaliana is induced and specifically targeted to the extrahaustorial membrane (EHM), an enigmatic interfacial membrane believed to be derived from the host cell plasma membrane. There, RPW8.2 activates a salicylic acid (SA) signaling-dependent defense strategy that concomitantly enhances the encasement of the haustorial complex and onsite accumulation of H(2)O(2), presumably for constraining the haustorium while reducing oxidative damage to the host cell. Targeting of RPW8.2 to the EHM, however, is SA independent and requires function of the actin cytoskeleton. Natural mutations that impair either defense activation or EHM targeting of RPW8.2 compromise the efficacy of RPW8.2-mediated resistance. Thus, the interception of haustoria is key for RPW8-mediated broad-spectrum mildew resistance.

DOI10.1105/tpc.109.067587
Alternate JournalPlant Cell
PubMed ID19749153
PubMed Central IDPMC2768920