Barley endosomal MONENSIN SENSITIVITY1 is a target of the powdery mildew effector CSEP0162 and plays a role in plant immunity

Wenlin Liao, Mads E. Nielsen, Carsten Pedersen, Wenjun Xie, Hans Thordal-Christensen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

11 Citations (Scopus)
28 Downloads (Pure)

Abstract

Encasements formed around haustoria and biotrophic hyphae as well as hypersensitive reaction (HR) cell death are essential plant immune responses to filamentous pathogens. In this study we examine the components that may contribute to the absence of these responses in susceptible barley attacked by the powdery mildew fungus. We find that the effector CSEP0162 from this pathogen targets plant MONENSIN SENSITIVITY1 (MON1), which is important for the fusion of multivesicular bodies to their target membranes. Overexpression of CSEP0162 and silencing of barley MON1 both inhibit encasement formation. We find that the Arabidopsis ecotype No-0 has resistance to powdery mildew, and that this is partially dependent on MON1. Surprisingly, we find the MON1-dependent resistance in No-0 not only includes an encasement response, but also an effective HR. Similarly, silencing of MON1 in barley also blocks Mla3-mediated HR-based powdery mildew resistance. Our results indicate that MON1 is a vital plant immunity component, and we speculate that the barley powdery mildew fungus introduces the effector CSEP0162 to target MON1 and hence reduce encasement formation and HR.

Original languageEnglish
JournalJournal of Experimental Botany
Volume74
Issue number1
Pages (from-to)118-129
ISSN0022-0957
DOIs
Publication statusPublished - 2023

Keywords

  • Barley powdery mildew
  • Blumeria hordei
  • effector
  • encasement
  • Hordeum vulgare
  • immunity
  • MON1
  • multivesicular body
  • pathogen resistance
  • CELL-DEATH
  • DISEASE RESISTANCE
  • ARABIDOPSIS
  • GENES
  • DEFENSE
  • GTPASE
  • PAPILLAE
  • TETRACONAZOLE
  • TRAFFICKING
  • ACTIVATION

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