Plant extracellular vesicles contain diverse small RNA species and are enriched in 10-17 nucleotide “tiny” RNAs (bioRxiv)

Small RNAs are known to move between cells and even between organisms. Studies in mammals have shown that extracellular vesicles (EVs) can contribute to small RNA transport, and recently small-RNA containing EVs were identified in plants. Baldrich et al. extend this work with an analysis of the types of small RNAs contained in plant EVs. Interestingly, while the typical distribution of small RNAs is dominated by 21-24 nt lengths, small RNAs in EVs are notably smaller than with the majority 10-17 nt, so are described as tiny RNAs (tyRNAs). Many of these appear to be derived from the loop region of processed miRNAs, in contrast to tyRNAs found outside of EVs, suggesting that the EVs are selectively packaged with a subset of tyRNAs.  As yet, the function of these EVs and they tyRNAs they contain remain uncertain. (Summary by Mary Williams) bioRxiv 10.1101/472928