Long-distance transport of mRNA via parenchyma cells  and phloem across the host-parasite junction in Cuscuta.
It has been shown that the parasitic plant dodder (Cuscuta pentagona) establishes a continuous vascular system through which water and nutrients are drawn. Along with solutes, viruses and proteins, mRNA transcripts are transported from the host to the parasite. The path of the transcripts and their stability in the parasite have yet to be revealed. To discover the route of mRNA transportation, the in situ reverse transcriptase-polymerase chain reaction (RT-PCR) technique was used to locally amplify host transcript within parasitic tissue. The stability of host mRNA molecules was also checked by monitoring specific transcripts along the growing dodder thread. Four mRNAs, alpha and beta subunits of PYROPHOSPHATE (PPi)-DEPENDENT PHOSPHOFRUCTOKINASE (LePFP), the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), and GIBBERELLIC ACID INSENSITIVE (LeGAI), were found to move from host (tomato (Solanum lycopersicum)) to dodder. LePFP mRNA was localized to the dodder parenchyma cells and to the phloem. LePFP transcripts were found in the growing dodder stem up to 30 cm from the tomato-dodder connection. These results suggest that mRNA molecules are transferred from host to parasite via symplastic connections between parenchyma cells, move towards the phloem, and are stable for a long distance in the parasite. This may allow developmental coordination between the parasite and its host.
David-Schwartz
Rakefet
R
Section of Plant Biology, University of California, Davis, CA 95616, USA.
Runo
Steven
S
Section of Plant Biology, University of California, Davis, CA 95616, USA.|Department of Biochemistry and Biotechnology, Kenyatta University, P.O. Box 43844, Nairobi, Kenya.
Townsley
Brad
B
Section of Plant Biology, University of California, Davis, CA 95616, USA.
Machuka
Jesse
J
Department of Biochemistry and Biotechnology, Kenyatta University, P.O. Box 43844, Nairobi, Kenya.
Sinha
Neelima
N
Section of Plant Biology, University of California, Davis, CA 95616, USA.
D001692:Biological Transport; D034182:Cuscuta / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D006790:Host-Parasite Interactions; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism / Q000469:parasitology*; D000455:Medicago sativa / Q000235:genetics / Q000378:metabolism / Q000469:parasitology*; D052585:Phloem / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger