PT - JOURNAL ARTICLE AU - Oliver Johanndrees AU - Erin L. Baggs AU - Charles Uhlmann AU - Federica Locci AU - Henriette L. Läßle AU - Katharina Melkonian AU - Kiara Käufer AU - Joram A. Dongus AU - Hirofumi Nakagami AU - Ksenia V. Krasileva AU - Jane E. Parker AU - Dmitry Lapin TI - Differential <em>EDS1</em> requirement for cell death activities of plant TIR-domain proteins AID - 10.1101/2021.11.29.470438 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.11.29.470438 4099 - http://biorxiv.org/content/early/2021/11/30/2021.11.29.470438.1.short 4100 - http://biorxiv.org/content/early/2021/11/30/2021.11.29.470438.1.full AB - Toll/interleukin-1 Receptor (TIR) domains are integral to immune systems across all domains of life. TIRs exist as single-domain and as larger receptor or adaptor proteins. In plants, TIRs constitute N-terminal domains of nucleotide-binding leucine-rich repeat (NLR) immune receptors. Although TIR-NLR and TIR signaling requires the Enhanced disease susceptibility 1 (EDS1) protein family, TIR domains persist in species that have incomplete or no EDS1 members. To assess whether particular TIR groups appear with EDS1, we searched for TIR-EDS1 co-occurrence patterns. Using a large-scale phylogenetic analysis of TIR domains from 39 algae and land plant species, we identify four conserved TIR groups, two of which are TIR-NLRs present in eudicots and two are more widespread. Presence of one TIR-only protein group is highly correlated with EDS1 and members of this group elicit EDS1-dependent cell death. By contrast, a more widely represented TIR group of TIR-NB-WD40/TPR (TNP) proteins (formerly called XTNX) has at least one member which can induce EDS1-independent cell death. Our data provide a new phylogeny-based plant TIR classification and identify TIR groups that appear to have evolved with and are dependent on EDS1, while others have EDS1-independent activity.One sentence summary Land plants have evolved four conserved TIR groupsCompeting Interest StatementThe authors have declared no competing interest.