title: Arabidopsis 14-3-3 lambda is a positive regulator of RPW8-mediated disease resistance.
abstract: The RPW8 locus from Arabidopsis thaliana Ms-0 includes two functional paralogous genes (RPW8.1 and RPW8.2) and confers broad-spectrum resistance via the salicylic acid-dependent signaling pathway to the biotrophic fungal pathogens Golovinomyces spp. that cause powdery mildew diseases on multiple plant species. To identify proteins involved in regulation of the RPW8 protein function, a yeast two-hybrid screen was performed using RPW8.2 as bait. The 14-3-3 isoform lambda (designated GF14lambda) was identified as a potential RPW8.2 interactor. The RPW8.2-GF14lambda interaction was specific and engaged the C-terminal domain of RPW8.2, which was confirmed by pulldown assays. The physiological impact of the interaction was revealed by knocking down GF14lambda by T-DNA insertion, which compromised basal and RPW8-mediated resistance to powdery mildew. In addition, over-expression of GF14lambda resulted in hypersensitive response-like cell death and enhanced resistance to powdery mildew via the salicylic acid-dependent signaling pathway. The results from this study suggest that GF14lambda may positively regulate the RPW8.2 resistance function and play a role in enhancing basal resistance in Arabidopsis.
authors.affiliation: Center for Biosystems Research, University of Maryland Biotechnology Institute, Rockville, MD 20850, USA.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Yang
authors.forename: Wenming
authors.initials: W
authors.lastname: Wang
authors.forename: Mark
authors.initials: M
authors.lastname: Coleman
authors.forename: Undral
authors.initials: U
authors.lastname: Orgil
authors.forename: Jiayue
authors.initials: J
authors.lastname: Feng
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Ma
authors.forename: Robert
authors.initials: R
authors.lastname: Ferl
authors.forename: John G
authors.initials: JG
authors.lastname: Turner
authors.forename: Shunyuan
authors.initials: S
authors.lastname: Xiao
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D016923:Cell Death; D018506:Gene Expression Regulation, Plant; D010935:Plant Diseases / Q000276:immunology; D011485:Protein Binding; D020156:Salicylic Acid / Q000378:metabolism
chemical_list: D048948:14-3-3 Proteins; D029681:Arabidopsis Proteins; C418463:RPW8.2 protein, Arabidopsis; D020156:Salicylic Acid; C117576:AFT1 protein, Arabidopsis