A barley powdery mildew fungus non-autonomous retrotransposon encodes a peptide that supports penetration success on barley

Mathias Nottensteiner, Bernd Zechmann, Christopher McCollum, Ralph Hückelhoven

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

Pathogens overcome plant immunity by means of secreted effectors. Host effector targets often act in pathogen defense, but might also support fungal accommodation or nutrition. The barley ROP GTPase HvRACB is involved in accommodation of fungal haustoria of the powdery mildew fungus Blumeria graminis f.sp. hordei (Bgh) in barley epidermal cells. We found that HvRACB interacts with the ROP-interactive peptide 1 (ROPIP1) that is encoded on the active non-long terminal repeat retroelement Eg-R1 of Bgh. Overexpression of ROPIP1 in barley epidermal cells and host-induced post-transcriptional gene silencing (HIGS) of ROPIP1 suggested that ROPIP1 is involved in virulence of Bgh. Bimolecular fluorescence complementation and co-localization supported that ROPIP1 can interact with activated HvRACB in planta. We show that ROPIP1 is expressed by Bgh on barley and translocated into the cytoplasm of infected barley cells. ROPIP1 is recruited to microtubules upon co-expression of MICROTUBULE ASSOCIATED ROP GTPase ACTIVATING PROTEIN (HvMAGAP1) and can destabilize cortical microtubules. The data suggest that Bgh ROPIP targets HvRACB and manipulates host cell microtubule organization for facilitated host cell entry. This points to a possible neo-functionalization of retroelement-derived transcripts for the evolution of a pathogen virulence effector.

Original languageEnglish
Pages (from-to)3745-3758
Number of pages14
JournalJournal of Experimental Botany
Volume69
Issue number15
DOIs
StatePublished - 27 Jun 2018

Keywords

  • Blumeria graminis
  • Hordeum vulgare
  • ROP GTPase
  • effector-triggered susceptibility
  • microtubule
  • retrotransposon
  • susceptibility factor
  • virulence

Fingerprint

Dive into the research topics of 'A barley powdery mildew fungus non-autonomous retrotransposon encodes a peptide that supports penetration success on barley'. Together they form a unique fingerprint.

Cite this