A new biochemistry connecting pathogen detection to induced defense in plants

New Phytol. 2022 May;234(3):819-826. doi: 10.1111/nph.17924. Epub 2022 Feb 5.

Abstract

Plant cell surface and intracellular immune receptors recognizing pathogen attack utilize the same defense machineries to mobilize resistance. New genetic, protein structural and biochemical information on receptor activation and signaling is transforming understanding of how their shared defense network operates. We discuss the biochemical activities of two classes of intracellular nucleotide-binding/leucine-rich repeat (NLR) receptor - one forming a Ca2+ channel, the other an NADase enzyme - which define engagement of enhanced disease susceptibility 1 (EDS1)-family heterodimers and cofunctioning helper NLRs (RNLs) to connect receptor systems and amplify defenses. Toll-interleukin-1 receptor (TIR) domain NLR receptors and TIR-domain proteins, with a capacity to produce NAD+-derived small molecules, require EDS1 dimers and RNLs for defense induction. The TIR-driven EDS1/RNL modules emerge as central elements in Ca2+ -based immunity signaling initiated by receptors outside and inside host cells.

Keywords: EDS1; NADase; RNL; TIR; disease resistance; effector-triggered immunity; immune receptor; pattern-triggered immunity.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis Proteins* / metabolism
  • Arabidopsis* / genetics
  • NLR Proteins / metabolism
  • Plant Diseases
  • Plant Immunity / genetics
  • Plants / metabolism

Substances

  • Arabidopsis Proteins
  • NLR Proteins