MicroRNAs from the parasitic plant Cuscuta campestris target host messenger RNAs

There’s only one thing worse than having a parasite suck the life juices out of you, and that’s having a parasite suck the life juices out of you while simultaneously injecting you with miRNAs to increase your vulnerability. Shahid et al. looked at microRNAs isolated from dodder (Cuscuta campestris), which parasistizes a wide range of eudicots. They found that during parasitism dodder produces 22 nt miRNAs that recognize mRNA sequences of many of its hosts; 22 nt miRNAs are rare and associated with the production of siRNAs from their targets, which can lead to enhanced gene silencing. Mutation of one of the targeted genes, SIEVE ELEMENT OCCLUSION RELATED 1 (SEOR1) led to an increase in biomass of the parasite, which suggests that dodder’s miRNA production contributes to its success as a parasite.  bioRxiv 10.1101/180497