Abstract Detail

Host/Plant Pathogen Interactions and Plant Health Management

Copeland, Charles [1], Woloshen, Virginia [1], Li, Xin [1].

The role of CDC48A in the negative regulation of R protein-mediated immunity.

In order to be successful, all multicellular organisms must be able to defend themselves against potentially harmful microbes. Plant Resistance (R) proteins, many of which contain nucleotide-binding and leucine-rich repeat (NLR) domains, perceive effector proteins produced by invading pathogens and activate downstream defense signalling. This results in effective immunity against the pathogen. However, excessive accumulation of R proteins results in an autoimmune response even in the absence of pathogen interaction, which is detrimental to plant growth. Plants must therefore control R protein accumulation through delicate mechanisms, including degradation via the 26S proteasome pathway. However, the details of this regulation are still unclear. A forward genetic screen was conducted for negative regulators of R protein-mediated immunity, based on enhancement of the autoimmune phenotype of snc1, a gain-of-function NLR mutant. We identified a partial loss-of-function allele of CDC48A, which encodes an ATPase that is highly conserved throughout eukaryotes. Although CDC48A has an essential function in Arabidopsis, its role in plant immunity has not been reported. The cdc48A mutant displays a dwarf phenotype, constitutive Pathogenesis Related 2 gene expression, and enhanced disease resistance. The immune phenotype of cdc48A is dependent on EDS1 and is suppressed by high temperature, indicating that CDC48A may regulate Toll/Interleukin-1 Receptor (TIR) type R proteins. CDC48 interacts with MUSE3, an E4 enzyme known to target R proteins including SNC1 for degradation. Therefore, CDC48 may facilitate the proteasome-mediated degradation of R proteins such as SNC1.

1 - University of British Columbia, Michael Smith Laboratories and Botany, 3529 - 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada

Keywords:
none specified

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PPA017
Abstract ID:436
Candidate for Awards:CSPB President's Award for Best Student Presentation