Phytosterol metabolism in plant positive-strand RNA virus replication

The genome of most plant viruses consists of a single positive-strand of RNA (+ ssRNA). Successful replication of these viruses is fully dependent on the endomembrane system of the infected cells, which experiences a massive proliferation and a profound reshaping that enables assembly of the macromolecular complexes where virus genome replication occurs. Assembly of these viral replicase complexes (VRCs) requires a highly orchestrated interplay of multiple virus and co-opted host cell factors to create an optimal microenvironment for efficient assembly and functioning of the virus genome replication machinery. It is now widely accepted that VRC formation involves the recruitment of high levels of sterols, but the specific role of these essential components of cell membranes and the precise molecular mechanisms underlying sterol enrichment at VRCs are still poorly known. In this review, we intend to summarize the most relevant knowledge on the role of sterols in ( +)ssRNA virus replication and discuss the potential of manipulating the plant sterol pathway to help plants fight these infectious agents.

Automated summary

The genome of most plant viruses consists of a single positive-strand of RNA (+ ssRNA) and successful replication depends on the endomembrane system of infected cells, which undergoes massive proliferation and reshaping. The assembly of viral replicase complexes (VRCs) requires a coordinated interaction of virus and host factors, with high levels of sterols involved in creating an optimal microenvironment for efficient replication. The specific role and molecular mechanisms of sterols in VRC formation are still poorly understood, but manipulating plant sterol pathways may offer potential strategies to combat these infectious agents.