Accurate and adequate spatiotemporal expression and localization of RPW8.2 is key to activation of resistance at the host-pathogen interface.

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TitleAccurate and adequate spatiotemporal expression and localization of RPW8.2 is key to activation of resistance at the host-pathogen interface.
Publication TypeJournal Article
Year of Publication2010
AuthorsWang, W, Berkey, R, Wen, Y, Xiao, S
JournalPlant Signal Behav
Volume5
Issue8
Pagination1002-5
Date Published2010 Aug
ISSN1559-2324
KeywordsAmino Acid Motifs, Arabidopsis, Arabidopsis Proteins, Cell Membrane, Host-Pathogen Interactions, Membrane Proteins, Plant Diseases, Recombinant Fusion Proteins, Sequence Deletion
Abstract

Numerous fungal and oomycete pathogens penetrate the plant cell wall and extract nutrition from the host cells by a feeding structure called the haustorium. We recently revealed that the Arabidopsis resistance protein RPW8.2 is specifically targeted to the extrahaustorial membrane (EHM) for activation of haustorium-targeted resistance to powdery mildew pathogens. Consistent with its EHM-localization, RPW8.2 contains a putative transmembrane (TM) domain at its N-terminus. Here, we show that translational fusion of YFP to the N-terminus of RPW8.2 results in localization of YFP-RPW8.2 to both the plasma membrane and the EHM, and loss of RPW8.2's defense function. We also show that deletion of the TM domain results in mis-localization of the RPW8.2-YFP fusion protein and extremely low levels of accumulation. These results indicate that an intact N-terminal TM domain is necessary for EHM-specific localization and defense function of RPW8.2. In addition, we show that when expressed from the strong constitutive 35S viral promoter, RPW8.2 accumulates at low levels in the EHM insufficient to activate resistance, highlighting the importance of stronger spatiotemporal expression of RPW8.2 from its native promoter. Taken together, our results indicate that accurate and adequate spatiotemporal expression and localization of RPW8.2 is key to activation of resistance at the host-pathogen interface.

Alternate JournalPlant Signal Behav
PubMed ID20864817
PubMed Central IDPMC3115180