The E3 Ligase APIP10 Connects the Effector AvrPiz-t to the NLR Receptor Piz-t in Rice

PLoS Pathog. 2016 Mar 31;12(3):e1005529. doi: 10.1371/journal.ppat.1005529. eCollection 2016 Mar.

Abstract

Although nucleotide-binding domain, leucine-rich repeat (NLR) proteins are the major immune receptors in plants, the mechanism that controls their activation and immune signaling remains elusive. Here, we report that the avirulence effector AvrPiz-t from Magnaporthe oryzae targets the rice E3 ligase APIP10 for degradation, but that APIP10, in return, ubiquitinates AvrPiz-t and thereby causes its degradation. Silencing of APIP10 in the non-Piz-t background compromises the basal defense against M. oryzae. Conversely, silencing of APIP10 in the Piz-t background causes cell death, significant accumulation of Piz-t, and enhanced resistance to M. oryzae, suggesting that APIP10 is a negative regulator of Piz-t. We show that APIP10 promotes degradation of Piz-t via the 26S proteasome system. Furthermore, we demonstrate that AvrPiz-t stabilizes Piz-t during M. oryzae infection. Together, our results show that APIP10 is a novel E3 ligase that functionally connects the fungal effector AvrPiz-t to its NLR receptor Piz-t in rice.

Publication types

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

MeSH terms

  • Magnaporthe
  • Oryza / enzymology
  • Oryza / microbiology*
  • Plant Diseases / microbiology*
  • Ubiquitin-Protein Ligases / metabolism*
  • Ubiquitination / immunology

Substances

  • Ubiquitin-Protein Ligases

Grants and funding

This work was funded by NSF-IOS (#1120949), and the OARDC-OSU SEEDS program to GLW, and by grants from the Natural Science Foundation of China to BZ (30971878) and YN (31101405). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.