An EDS1-SAG101 Complex Is Essential for TNL-Mediated Immunity in Nicotiana benthamiana. Issue 10 (2nd July 2019)

• Record Type: Journal Article
• Authors: Gantner, Johannes; Ordon, Jana; Kretschmer, Carola; Guerois, Raphaël; Stuttmann, Johannes
• Is Part Of: The Plant Cell. Volume 31:Issue 10(2019)
• Page Start: 2456
• Page End: 2474
• Publication Date: 2019-07-02
• DOI: 10.1105/tpc.19.00099
• Languages: English
• ISSNs: 1040-4651

Abstract

Abstract : The model Solanaceous plant Nicotiana benthamiana is established as a system for analysis of the role of EDS1 complexes in signaling downstream of TIR-domain containing immune receptors Abstract: Heterodimeric complexes containing the lipase-like protein ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) are regarded as central regulators of plant innate immunity. In this context, a complex of EDS1 with PHYTOALEXIN DEFICIENT4 (PAD4) is required for basal resistance and signaling downstream of immune receptors containing an N-terminal Toll-interleukin-1 receptor-like domain (TNLs) in Arabidopsis ( Arabidopsis thaliana ). Here we analyze EDS1 functions in the model Solanaceous plant Nicotiana benthamiana ( Nb ). Stable Nb mutants deficient in EDS1 complexes are not impaired in basal resistance, a finding which contradicts a general role for EDS1 in immunity. In Nb, PAD4 demonstrated no detectable immune functions, but TNL-mediated resistance responses required EDS1 complexes incorporating a SENESCENCE ASSOCIATED GENE101 (SAG101) isoform. Intriguingly, SAG101 is restricted to those genomes also encoding TNL receptors, and we propose it may be required for TNL-mediated immune signaling in most plants, except the Brassicaceae. Transient complementation in Nb was used for accelerated mutational analyses while avoiding complex biotic interactions. We identify a large surface essential for EDS1-SAG101 immune functions that extends from the N-terminal lipase domains to the C-terminal EDS1-PAD4 domains and might mediate interaction partner recruitment. Furthermore, this work demonstrates the value of genetic resources in Nb, which will facilitate elucidation of EDS1 functions.