Universität zu Köln

Johanndrees, Oliver ORCID: 0000-0001-6659-3951 (2022). Comparative Phylogenetic and Molecular Analysis of Plant TIR Domain Proteins. PhD thesis, Universität zu Köln.

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Abstract

Toll/Interleukin 1 receptor (TIR) domains are found across kingdoms of life, where they serve as integral components in immune and cell death pathways. TIRs occur as single-domain proteins and parts of larger protein receptor complexes with common sets of associated domains. Self-association and enzymatic activity are common TIR features, conserved across kingdoms. In plants, TIRs constitute N-terminal signaling domains of intracellular nucleotide-binding leucine-rich repeat receptors (NLRs), which form an important part of the plant immune system to detect pathogen interference. Activated TIR-NLRs (TNLs) produce distinct enzymatic metabolites that serve as second messengers in immunity. While in plants, all studied TIR signaling requires the ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) protein family, TIR domains were predicted in plant species with an incomplete or missing EDS1 family. It remains unknown whether TIRs and EDS1 family members co-evolved in plants, and how TIRs evolved in plants without EDS1. The work presented here provides a large-scale phylogenetic analysis of TIR domains from 39 algae and land plant species, which identified four conserved TIR groups shared by multiple plant clades. Using the phylogeny, this study provides a comprehensive phylogeny-based nomenclature for plant TIRs. Among the conserved groups is a TIR-only group, which highly correlates with EDS1 in tested species and induces EDS1-dependent cell death. In contrast, a member of the most widespread group of TIR-NB-TPR (TNP) proteins, which persisted in plants without EDS1, induces EDS1-independent cell death. This is the first reported incidence of EDS1-independent cell death, induced by a plant TIR domain protein to date, and is in striking contrast to the majority of studied TIRs, including TNLs. This study furthermore provides a comprehensive set of conserved TIR-only and TNP mutants, generated by CRISPR/Cas9 mutagenesis, to study involvement of conserved TIRs in immune signaling pathways.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Johanndrees, Oliver ojohannd@smail.uni-koeln.de orcid.org/0000-0001-6659-3951 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-645462
Date:	19 September 2022
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Außeruniversitäre Forschungseinrichtungen > MPI for Plant Breeding Research
Subjects:	Life sciences
Uncontrolled Keywords:	Keywords Language TIR; phylogeny; cell death; plant immunity English
Date of oral exam:	16 November 2022
Referee:	Name Academic Title Parker, Jane E. Prof. Dr. Döhlemann, Gunther Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/64546