Trafficking of mRNA from tomato to dodder

Experiment description: An intriguing new paradigm in plant biology is that systemically-mobile mRNAs play a role in coordinating development. In this process, specific mRNAs are loaded into the phloem transport stream for translocation to distant tissues, where they may impact developmental processes. However, despite its potential significance for plant growth regulation, mRNA trafficking remains poorly understood and challenging to study. Here we show that phloem-mobile mRNAs can also traffic between widely divergent species from a host to the plant parasite, lespedeza dodder (Cuscuta pentagona Engelm.). Reverse transcriptase PCR (RT-PCR) and microarray analysis were used to detect specific tomato transcripts in dodder grown on tomato (Lycopersicon esculentum Mill.) that were not present in control dodder grown on other host species. The foreign transcripts included LeGAI, which has been previously shown to be translocated in the phloem, as well as nine other transcripts not reported to be mobile. Dodders are parasitic plants that obtain resources by drawing from the phloem of a host plant, and have joint plasmodesmata with host cortical cells. Although viruses are known to move between dodder and its hosts, translocation of endogenous plant mRNA has not been reported. These results point to a potentially new level of interspecies communication, and raise questions about the ability of parasites to recognize, use, and respond to transcripts acquired from their hosts.

Author: James H Westwood

Contact: James H Westwood (, Plant Pathol. Physiol. Weed Sci. of Virginia Tech

PubMed ID: 17189329

External link: GEO