Mobile Host mRNAs Are Translated to Protein in the Associated Parasitic Plant .

spp. are obligate parasites that connect to host vascular tissue using a haustorium. In addition to water, nutrients, and metabolites, a large number of mRNAs are bidirectionally exchanged between spp. and their hosts. This trans-specific movement of mRNAs raises questions about whether these molecules function in the recipient species. To address the possibility that mobile mRNAs are ultimately translated, we built upon recent studies that demonstrate a role for transfer RNA (tRNA)-like structures (TLSs) in enhancing mRNA systemic movement. was grown on that expressed a β-glucuronidase () reporter transgene either alone or in fusions. Histochemical staining revealed localization in tissue of grown on with fusions, but not in grown on with alone. This corresponded with detection of transcripts in on with , but not in on with alone. Similar results were obtained with host plants expressing the same constructs containing an endoplasmic reticulum localization signal. In , GUS activity was localized in the companion cells or phloem parenchyma cells adjacent to sieve tubes. We conclude that host-derived mRNAs are translated in and that the TLS fusion enhances RNA mobility in the host-parasite interactions.