Phytophthora effector targets a novel component of small RNA pathway in plants to promote infection

• DOI: 10.1073/pnas.1421475112
• Publication Date: 2015-04-21T02:51:43Z
• Authors: Yongli Qiao; Jinxia Shi; Yi Zhai; Yingnan Hou; Wenbo Ma
• Keywords: Phytophthora; Nicotiana; 0301 basic medicine; Protein Structure; RNA helicase; Arabidopsis; Veterinary and Food Sciences; Plant Biology; Genetically Modified; Small Interfering; gene silencing; 03 medical and health sciences; Tobacco; Genetics; 2.1 Biological and endogenous factors; small RNA; Gene Silencing; Aetiology; RNA, Small Interfering; Alleles; Plant Diseases; 580; Cell Nucleus; Agricultural; Virulence; Plant; Biological Sciences; Plants; RxLR effector; Plants, Genetically Modified; Protein Structure, Tertiary; MicroRNAs; Infectious Diseases; Phenotype; RNA, Plant; Phytophthora pathogenesis; RNA; RNA Interference; Infection; Tertiary; RNA Helicases; Biotechnology

Significance

Phytophthora is a major threat to agriculture. However, the molecular interaction of these severe pathogens with plant hosts is poorly understood. Here, we report that the Phytophthora Suppressor of RNA Silencing 1 (PSR1) effectively promotes infection in Arabidopsis thaliana by directly targeting an essential protein containing a aspartate–glutamate–alanine–histidine-box RNA helicase domain. This PSR1-Interacting Protein 1 (PINP1) is required for the accumulation of distinct classes of endogenous small RNAs and acts as a positive regulator of plant immunity. Silencing of PINP1 impaired the assembly of microRNA-processing complexes in the nucleus, leading to defects in development and immunity. This study revealed a conserved RNA helicase as a regulator of RNA silencing and provides mechanistic insight into Phytophthora pathogenesis.