title: Dominant negative RPW8.2 fusion proteins reveal the importance of haustorium-oriented protein trafficking for resistance against powdery mildew in Arabidopsis.
abstract: Powdery mildew fungi form feeding structures called haustoria inside epidermal cells of host plants to extract photosynthates for their epiphytic growth and reproduction. The haustorium is encased by an interfacial membrane termed the extrahaustorial membrane (EHM). The atypical resistance protein RPW8.2 from Arabidopsis is specifically targeted to the EHM where RPW8.2 activates haustorium-targeted (thus broad-spectrum) resistance against powdery mildew fungi. EHM-specific localization of RPW8.2 suggests the existence of an EHM-oriented protein/membrane trafficking pathway during EHM biogenesis. However, the importance of this specific trafficking pathway for host defense has not been evaluated via a genetic approach without affecting other trafficking pathways. Here, we report that expression of EHM-oriented, nonfunctional RPW8.2 chimeric proteins exerts dominant negative effect over functional RPW8.2 and potentially over other EHM-localized defense proteins, thereby compromising both RPW8.2-mediated and basal resistance to powdery mildew. Thus, our results highlight the importance of the EHM-oriented protein/membrane trafficking pathway for host resistance against haustorium-forming pathogens such as powdery mildew fungi.
authors.affiliation: a Institute for Bioscience and Biotechnology Research ; University of Maryland ; Rockville , MD USA.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zhang
authors.forename: Robert
authors.initials: R
authors.lastname: Berkey
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Pan
authors.forename: Wenming
authors.initials: W
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Ma
authors.forename: Harlan
authors.initials: H
authors.lastname: King
authors.forename: Shunyuan
authors.initials: S
authors.lastname: Xiao
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001203:Ascomycota; D060467:Disease Resistance; D056229:Fungal Structures / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves; D030821:Plants, Genetically Modified; D021381:Protein Transport
chemical_list: D029681:Arabidopsis Proteins; C418463:RPW8.2 protein, Arabidopsis
keywords: Arabidopsis; EHM, extrahaustorial membrane; PM, plasma membrane; RPW8; eds, enhanced disease susceptibility; extrahaustorial membrane; haustorium; powdery mildew; protein targeting
references.citation: Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3718-23
references.pmid: 10737809
references.citation: Plant J. 2014 Sep;79(5):835-47
references.pmid: 24941879
references.citation: Plant Cell. 2001 Feb;13(2):337-50
references.pmid: 11226189
references.citation: Plant J. 2001 Feb;25(3):335-48
references.pmid: 11208025
references.citation: Proc Natl Acad Sci U S A. 2001 Aug 28;98(18):10475-80
references.pmid: 11504929
references.citation: J Cell Biol. 2001 Oct 15;155(2):239-49
references.pmid: 11591731
references.citation: Plant Cell. 2003 Jan;15(1):33-45
references.pmid: 12509520
references.citation: Plant J. 2004 Feb;37(4):528-38
references.pmid: 14756761
references.citation: Plant J. 2005 Apr;42(1):95-110
references.pmid: 15773856
references.citation: Plant J. 2005 Nov;44(3):516-29
references.pmid: 16236160
references.citation: Plant J. 2007 Jan;49(2):302-12
references.pmid: 17241452
references.citation: Genetics. 2007 Aug;176(4):2317-33
references.pmid: 17565954
references.citation: Mol Plant Microbe Interact. 2007 Aug;20(8):966-76
references.pmid: 17722700
references.citation: Nature. 2008 Feb 14;451(7180):835-40
references.pmid: 18273019
references.citation: Plant Cell. 2009 Sep;21(9):2898-913
references.pmid: 19749153
references.citation: Plant J. 2009 Nov;60(3):539-50
references.pmid: 19624472
references.citation: Plant J. 2011 Feb;65(4):610-21
references.pmid: 21208308
references.citation: Plant Signal Behav. 2010 Aug;5(8):1002-5
references.pmid: 20864817
references.citation: Curr Opin Plant Biol. 2011 Dec;14(6):738-46
references.pmid: 21924669
references.citation: Mol Plant. 2012 Sep;5(5):1125-37
references.pmid: 22334594
references.citation: Plant Cell. 2013 Oct;25(10):4242-61
references.pmid: 24151293
references.citation: Plant Cell Physiol. 2014 Aug;55(8):1484-96
references.pmid: 24899552
references.citation: Science. 2001 Jan 5;291(5501):118-20
references.pmid: 11141561