GSE184641
Time course of trans-species miRNAs from Cuscuta campestris grown on Arabidopsis thaliana
Cuscuta campestris is an obligate stem parasite which uses an organ called the haustoria to divert water and photosynthates from the host.  Previously, we have identified that at the haustorial interface between Cuscuta campestris and Arabidopsis thaliana, miRNAs generated by the parasite are able to move into the host and regulate host gene expression.  This study identifies how long after attachment does trans-species miRNA transcription begin in Arabidopsis thaliana and Solanum lycopersicum, as well as identifying which stage of haustoria development they become detectable.  A time course was performed by harvesting interfaces every 24 hours post attachment, and samples were subjected to RNA extraction and sRNA sequencing. We have identified that in Arabidopsis thaliana, trans-species miRNAs become detectable two days post attachment. In S. lycopersicum, some trans-species miRNAs are detectable one day post attachment, but all become detectable by day 2.  Secondary siRNA accumulation was detected four days post attachment in both hosts.  In order to determine which stage of haustoria development trans-species miRNAs become detectable, vibratome sectioning was performed on the haustorial interfaces of both hosts.  By looking at the morphology of the developing haustoria, it was determined that trans-species miRNAs become detectable during the adhesive phase.  This suggests that trans-species miRNA production is one of the first steps of haustoria development, as the parasite tissue has not started to invade host tissue before they become detectable.    Overall design: Samples were taken every 24 hours for 15 days (days 0 through 14) after coiling of the parasite around the host stem. There were between 1 and 3 replicate samples per time point.