IntroductionPotato virus X (PVX) is a plant RNA virus. Its infection cycle includes invasion of the host plant, RNA replication, translation of viral proteins, cell-to-cell movement, and release of new virions. Upon infection, PVX releases its plus-strand RNA genome from the virion and produces a viral replicase using the host translation machinery. The replicase synthesizes negative-strand RNA. Subsequently, new plus-strand genomic RNAs (gRNAs) and subgenomic RNAs (sgRNAs) are produced. Movement and coat proteins are translated from sgRNAs for packaging and movement through plasmodesmata. In this mini-review, all aspects of the PVX viral infection cycle are discussed.ClassificationPotato virus X (PVX) is a small, non-enveloped virus, which has a monopartite plus-strand RNA genome. It therefore belongs to class IV of the Baltimore system. PVX is part of the Potexvirus genus. Along with eight other genera, this genus belongs to the family Alphaflexiviridae [1]. Virion Morphology and Contents PVX forms small filamentous virions that have a deeply grooved surface [2]. The flexible filaments consist of single-stranded genomic RNA plus coated with viral coat protein (CP). The helical structure has a pitch of 3.6 nm and contains 8 7/8 CP subunits per turn [3]. Full-length filaments have a template length of 515 nm and a diameter of 13 nm [4]. The CP consists of a single domain with high α-helix content [4]. The N-terminal part of this domain is exposed on the surface while the C-terminal region is buried in the virion. Several experiments indicate that CP is an O-glycoprotein. Equal amounts of galactose and fructose residues are O-linked to an acetylated serine residue at the N-terminal region [2]. This mediates the formation of a structured medium of the paper......but 10%. This despite obtaining high virus titers. Asymptomatic plants are considered carriers of PVX and are an important source of infection. In more severe conditions, necrotic streaks and significant mosaic, wrinkling and roughness of leaves may appear. Particularly in the case of mixed Potato Virus Y (PVY) infections, the yield loss can be up to 50%. Several potato plants carry PVX resistance genes. To date, two resistance genes have been identified. One gene product mediates systemic salicylic acid defense responses, while the other encodes the Rx protein. This protein has a nucleotide binding site (NBS) and a leucine-rich repeat (LRR). The native Rx fold confers an inactive conformation. During interactions with the viral CP, Rx partially unfolds, and thus its NBS-LRR domain [27]. This activates the signaling cascade mediating virus resistance.