Characteristics of long-distance mobile mRNAs from shoot to root in grafted plant species

Thousands of long-distance mobile mRNAs were identified from different grafting systems, based on high-throughput sequencing technology. Moreover, the long-distance delivery of RNAs was proved to involve multiple mechanisms. Here, we analyzed the homology, motif, and tRNA-like structure (TLS) of long-distance mobile mRNAs identified by RNA-seq as well as the RNA-binding protein (RBP) in nine grafting combinations including Arabidopsis thaliana, Vitis vinifera, Cucumis sativus, Citrullus lanatus, Nicotiana benthamiana, Malus domestica, Pyrus spp., Glycine max and Phaseolus vulgaris. Although several mRNAs were found to be shared in herbaceous, woody, and related species, the vast majority of long-distance mobile mRNAs were species-specific. Four non-specific movement-related motifs were identified, while the TLS was not necessary for mRNA long distance mobility. In addition, we found that RBPs were conserved among herbaceous and woody plants as well as related species. This paper reports a further in-depth analysis of the endogenous mechanisms by which the species-specific transportable mRNAs were selected by bioinformatics, in order to provide insights for future research on long-distance mobile mRNAs.