Researchers from Northwest A&F University recently reported the identification and functional characterization of tsRNAs in the oomycete pathogen Phytophthora sojae. They show that multiple tRNAs are processed into abundant tsRNAs, which accumulate in a similar developmental stage-specific manner and are negatively correlated with the expression of predicted target genes. Degradome sequencing and 5′ RLM RACE experiments indicate tsRNAs can trigger degradation of target transcripts. Transient expression assays using GUS sensor constructs confirmed the requirement of sequence complementarity in tsRNA-mediated RNA degradation in P. sojae.
These results show that the tsRNA are a class of functional endogenous sRNAs and suggest that tsRNA regulate gene expression through inducing sequence-specific degradation of target RNAs in oomycetes.