Characterization of the membrane-associated HaRxL17 Hpa effector candidate

Marie-cécile Caillaud, Sophie J. M. Piquerez, Jonathan D. G. Jones

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6 Citations (Scopus)


We examined changes to subcellular architecture during the compatible
interaction between the biotroph pathogen
Hyaloperonospora arabidopsidis (Hpa)
and its host Arabidopsis. Live-cell imaging
highlighted rearrangements in plant
cell membranes upon infection. In particular,
the tonoplast appeared close to the
extrahaustorial membrane surrounding
the haustorium. We investigated the
subcellular localization patterns of Hpa
RxLR effector candidates (HaRxLs)
in planta. This subcellular localization
screening led to the identification of
an extrahaustorial membrane-localized
effector, HaRxL17 that when stably
expressed in Arabidopsis increased plant
susceptibility to Hpa during compatible
and incompatible interactions. Here,
we report that the N-terminal part of
HaRxL17 is sufficient to target the
plant cell membranes. We showed that
both C- or N-terminal fluorescent-tagged
HaRxL17 localizes around Hpa haustoria,
in early and in late stages of infection.
As with Hpa infection, GFP-HaRxL17
also localizes around haustoria during
infection with Albugo laibachii. Thus,
HaRxL17 that increases plant susceptibility
to Hpa during both compatible
and incompatible interactions, localizes
around oomycete haustoria when stably
expressed in Arabidopsis.
Original languageEnglish
Pages (from-to)145-149
Number of pages5
JournalPlant Signaling & Behavior
Issue number1
Publication statusPublished - 1 Jan 2012


  • oomycete
  • effector
  • RxLR
  • haustoria
  • nucleus
  • membrane

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