title: Evidence for involvement of Dicer-like, Argonaute and histone deacetylase proteins in gene silencing in Phytophthora infestans.
abstract: Gene silencing may have a direct or indirect impact on many biological processes in eukaryotic cells, and is a useful tool for the determination of the roles of specific genes. In this article, we report silencing in Phytophthora infestans, an oomycete pathogen of potato and tomato. Gene silencing is known to occur in P. infestans, but its genetic basis has yet to be determined. Genes encoding the major components of the RNA interference (RNAi) pathway, Dicer-like (Pidcl1), Argonaute (Piago1-5) and RNA-directed RNA polymerase (Pirdr1), were identified in the P. infestans genome by comparative genomics, together with families of other genes potentially involved in gene silencing, such as histone deacetylases, histone methyltransferases, DEAD helicases, chromodomain proteins and a class 1 RNaseIII. Real-time reverse transcription-polymerase chain reaction demonstrated transcript accumulation for all candidate genes throughout the asexual lifecycle and plant infection, but at different levels of mRNA abundance. A functional assay was developed in which silencing of the sporulation-associated Picdc14 gene was released by the treatment of protoplasts with in vitro-synthesized double-stranded RNAs homologous to Pidcl1, Piago1/2 and histone deacetylase Pihda1. These results suggest that the components of gene silencing, namely Dicer-like, Argonaute and histone deacetylase, are functional in P. infestans. Our data demonstrate that this oomycete possesses canonical gene silencing pathways similar to those of other eukaryotes.
authors: Department of Plant Biology and Forest Genetics, Uppsala BioCenter, SLU, 750 07 Uppsala, Sweden. ramesh.vetukuri@slu.se
authors: Ramesh R
authors: RR
authors: Vetukuri
authors: Anna O
authors: AO
authors: Avrova
authors: Laura J
authors: LJ
authors: Grenville-Briggs
authors: Pieter
authors: P
authors: Van West
authors: Fredrik
authors: F
authors: Söderbom
authors: Eugene I
authors: EI
authors: Savenkov
authors: Stephen C
authors: SC
authors: Whisson
authors: Christina
authors: C
authors: Dixelius
mesh_terms: D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism; D020868:Gene Silencing; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism; D018551:Solanum lycopersicum / Q000382:microbiology; D010802:Phylogeny; D055750:Phytophthora infestans / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D034622:RNA Interference; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D011198:Solanum tuberosum / Q000382:microbiology
chemical_list: D060565:Argonaute Proteins; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D012324:RNA-Dependent RNA Polymerase; D006655:Histone Deacetylases