The N-terminal domains of NLR immune receptors exhibit structural and functional similarities across divergent plant lineages

Khong Sam Chia, Jiorgos Kourelis, Albin Teulet, Martin Vickers, Toshiyuki Sakai, Joseph F. Walker, Sebastian Schornack, Sophien Kamoun, Philip Carella

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

Nucleotide-binding domain and leucine-rich repeat (NLR) proteins are a prominent class of intracellular immune receptors in plants. However, our understanding of plant NLR structure and function is limited to the evolutionarily young flowering plant clade. Here, we describe an extended spectrum of NLR diversity across divergent plant lineages and demonstrate the structural and functional similarities of N-terminal domains that trigger immune responses. We show that the broadly distributed coiled-coil (CC) and toll/interleukin-1 receptor (TIR) domain families of nonflowering plants retain immune-related functions through translineage activation of cell death in the angiosperm Nicotiana benthamiana. We further examined a CC subfamily specific to nonflowering lineages and uncovered an essential N-terminal MAEPL motif that is functionally comparable with motifs in resistosome-forming CC-NLRs. Consistent with a conserved role in immunity, the ectopic activation of CCMAEPL in the nonflowering liverwort Marchantia polymorpha led to profound growth inhibition, defense gene activation, and signatures of cell death. Moreover, comparative transcriptomic analyses of CCMAEPL activity delineated a common CC-mediated immune program shared across evolutionarily divergent nonflowering and flowering plants. Collectively, our findings highlight the ancestral nature of NLR-mediated immunity during plant evolution that dates its origin to at least ∼500 million years ago.

Original languageEnglish
Pages (from-to)2491-2511
Number of pages21
JournalThe Plant Cell
Volume36
Issue number7
Early online date10 Apr 2024
DOIs
Publication statusPublished - Jul 2024

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