Archivio Journal of Plant Pathology

Abstract:

Viroids are sub-viral plant pathogens consisting of covalently closed circular RNAs that infect herbaceous and woody hosts. They do not code for any peptide or protein and therefore are fully dependent on the host machinery for most biological processes, including pathogenesis. Certain viroid-host combinations show severe symptoms but the biochemical bases of this process are currently unknown. In this work, we have characterized the symptoms induced by Hop stunt viroid (HSVd) when provided as a transgene in Nicotiana benthamiana plants, a natural non-host that is able to process and translocate HSVd. The presence of HSVd in this transgenic plant causes severe stunting and decrease in the leaf size, followed by strong alteration of flower development and reduced fertility. These symptoms are similar to those induced by HSVd in natural infections, indicating that in N. benthamiana HSVd expression mimics the metabolic disorders induced in natural hosts. Therefore, these transgenic plants may be useful to study the viroid-host interactions leading to pathogenesis.