Phytophthora have distinct endogenous small RNA populations that include short interfering and microRNAs: Phytophthora ramorum small RNA

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 ramorum mycelium small RNAs were sequenced and aligned to the P. ramorum genome for analysis. *Raw data files (fastq) are unavailable for this study.