Studies on viroid–host interactions have become essential to understand different aspects of the structure–function relationships in the RNA world. Work on viroid RNA has led to seminal discoveries in RNA biology. Over the last two decades, significant progress has been made as to how viroid RNA traffics within and among cells, and how these noncoding RNAs reach vascular tissue to systemically invade plants. The viroid RNA structure consists of different loops and bulges, flanked by double-stranded segments, which give rise to potential RNA motifs that can serve as guiding signals for their intra- and intercellular movement. In this chapter we update knowledge on viroid RNA movement and emphasize its potential as an ideal model to study RNA trafficking.

Work in the laboratories of G. Gomez and V. Pallas was supported by grants AGL2013-47886-R (GG) and BIO2014-54362-R (VP) from the Spanish Granting Agency (Direccion General Investigacion Cientifica) and PROMETEO program 2015/010 (Gen. Valenciana).

Peer reviewed

Capítulo 8.