Idenfication and characterization of SSD6 in Arabidopsis
W. XIE (1) (1) University of Copenhagen, Denmark

Plants protect themselves from pathogens by activating a defence signalling network. The Arabidopsis double mutant pen1 syp122 is dwarfed and mimics a response as if it was attacked by pathogens. Using EMS as mutagen on pen1 syp122, a triple mutant screen was performed. More than 200 partially rescued pen1 syp122 ssdx (suppressor of syntaxin-related death) lines were collected. SSD genes are typically required for pathogen defence. In one of those triple mutants, a novel defence component, SSD6, was identified by Mutmap. T-DNA insertion and overexpression studies confirmed the identity of SSD6. In total, five ssd6 mutant alleles were identified by complementation test and sequencing. SSD6 is a large protein with at least six domains with predicted functions. All plant species have homologues of SSD6, but none of these have been formally reported. Subcellular localization of wild-type and mutant versions of SSD6 was performed to help unraveling its function and those of its domains. Using our newly developed split-GFP Gateway vector system, a topology study showed SSD6 to be a membrane anchored cytosolic protein. ssd6 single mutants were inoculated by different pathogens to test SSD6’s involvement in defence. The position of SSD6 in the defence signalling network is being studied using pen1 syp122 ssd6 ssdy quadruple mutants.

Abstract Number: P7-219
Session Type: Poster