Research Interests: Regulation of meristem transition by mobile mRNA

In higher plants, recent findings indicate that many mRNAs not only serve as templates for translation but also act as systemic signals to fine-tune plant development. We are particularly interested in the mechanisms of RNA movement and the function of these phloem-mediated mobile mRNAs. To explore the functional complexity of mobile mRNA, RNA-seq was conducted to establish a phloem sap mRNA database from broccoli (Brassica oleracea). Analysis of this database identified 63 putative mobile mRNA involves in floral regulation. By use of Arabidopsis grafting experiments, we show that a number of mobile mRNAs indeed act non-cell autonomously to regulate floral initiation or floral reversion. Currently, we are investigating the function of other mobile mRNA in floral regulation or diverse developmental processes.

To investigate the mechanisms underlying intra- and inter-cellular trafficking of mobile mRNA, we adopted an MS2-GFP based mRNA labeling system to visualize real-time trafficking of mobile mRNA in living cells. We substantially reduced cytoplasmic fluorescent background to improve MS2 system, which allowed us to observe the cytoplasmic green fluorescence foci with an MS2-binding site dependent manner (Fig 1). ex vivo RNA images showed that mobile mRNA is targeted to plasmodesmata, presumably for cell-to-cell movement. To elucidate the molecular mechanism underlying long-distance movement of mobile mRNA, we established a biochemical approach and identified some phloem proteins interact with in vitro synthesized mobile mRNA. Analysis of these putative phloem proteins may provide us an opportunity to understand long-distance trafficking of mobile mRNA.