The WY domain in the Phytophthora effector PSR1 is required for infection and RNA silencing suppression activity

Peng Zhang, Yijuan Jia, Jinxia Shi, Chen Chen, Wenwu Ye, Yuanchao Wang, Wenbo Ma, Yongli Qiao

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Phytophthora pathogens manipulate host innate immunity by secreting numerous RxLR effectors, thereby facilitating pathogen colonization. Predicted single and tandem repeats of WY domains are the most prominent C-terminal motifs conserved across the Phytophthora RxLR superfamily. However, the functions of individual WY domains in effectors remain poorly understood. The Phytophthora sojae effector PSR1 promotes infection by suppressing small RNA biogenesis in plant hosts. We identified one single WY domain following the RxLR motif in PSR1. This domain was required for RNA silencing suppression activity and infection in Nicotiana benthamiana, Arabidopsis and soybean. Mutations of the conserved residues in the WY domain did not affect the subcellular localization of PSR1 but abolished its effect on plant development and resistance to viral and Phytophthora pathogens. This is at least in part due to decreased protein stability of the PSR1 mutants in planta. The identification of the WY domain in PSR1 allows predicts that a family of PSR1-like effectors also possess RNA silencing suppression activity. Mutation of the conserved residues in two members of this family, PpPSR1L from P. parasitica and PcPSR1L from P. capsici, perturbed their biological functions, indicating that the WY domain is critical in Phytophthora PSR1 and PSR1-like effectors.

Original languageEnglish
Pages (from-to)839-852
Number of pages14
JournalNew Phytologist
Issue number2
Publication statusPublished - Jul 2019


  • host–pathogen interaction
  • Phytophthora pathogenesis
  • PSR1
  • RNA silencing
  • RxLR effector
  • WY domains

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