Project description:Deep sequencing of small RNAs from three Phytophthora species, P. infestans, P. ramorum and P. sojae, was done to systematically analyze small RNA-generating components of Phytophthora genomes. We found that each species produces two distinct small RNA populations that are predominantly 21- or 25-nucleotides long. We present evidence that 25-nucleotide small RNAs are short-interfering RNAs that silence repetitive genetic elements. In contrast, 21-nucleotide small RNAs are associated with inverted repeats, including a novel microRNA family, and may function at the post-transcriptional level. Phytophthora infestans mycelium small RNAs were sequenced and aligned to the P. infestans genome for analysis.
Project description:Phytophthora spp. encode large sets of effector proteins and distinct populations of small RNAs (sRNAs). Reports suggest that pathogen-derived sRNAs can modulate the expression of plant defense genes. The experiments reported here were designed to shed light on impact of sRNAs in the potato-P. infestans interaction. We used the Argonaute or Ago1 from P. infestans tagged with GFP transformed into the 88069 strain to infect potato cv. Bintje plants. Collected leaf materials were used in co-immunoprecipitation experiments together with P. infestans harboring GFP (control GFP) and P. infestans mycelia grown on media (control mycelia). These three materials were sequenced at a Ion Proton platform. The reads length of 8-38 nt were adaptor-trimmed and mapped to the P. infestans genome and the Solanom tuberosum genome v4.04. Both P. infestans-associated and potato derived sRNAs were identified.