Help wanted: helper NLRs and plant immune responses

Curr Opin Plant Biol. 2019 Aug;50:82-94. doi: 10.1016/j.pbi.2019.03.013. Epub 2019 May 4.

Abstract

Plant nucleotide-binding domain and leucine-rich repeat-containing (NLR) proteins function as intracellular receptors in response to pathogens and activate effector-triggered immune responses (ETI). The activation of some sensor NLRs (sNLR) by their corresponding pathogen effector is well studied. However, the mechanisms by which the recently defined helper NLRs (hNLR) function to transduce sNLR activation into ETI-associated cell death and disease resistance remains poorly understood. We briefly summarize recent examples of sNLR activation and we then focus on hNLR requirements in sNLR-initiated immune responses. We further discuss how shared sequence homology with fungal self-incompatibility proteins and the mammalian mixed lineage kinase domain like pseudokinase (MLKL) proteins informs a plausible model for the structure and function of an ancient clade of plant hNLRs, called RNLs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Disease Resistance
  • Fungal Proteins
  • NLR Proteins
  • Plant Diseases*
  • Plant Immunity
  • Plant Proteins
  • Plants*

Substances

  • Fungal Proteins
  • NLR Proteins
  • Plant Proteins