The multifunctional helper component proteinase (HCpro) of potyviruses (genus Potyvirus; Potyviridae) shows self-interaction and interacts with other potyviral and host plant proteins. Host proteins that are pivotal to potyvirus infection include the eukaryotic translation initiation factor eIF4E and the isoform eIF(iso)4E, which interact with viral genome-linked protein (VPg). Here we show tha...

Monopartite members of the family Potyviridae utilize three virus-encoded proteinases to cleave the viral polyprotein into mature proteins. The amino-terminal region of the viral polyprotein is autolytically cleaved by the P1 proteinase. A domain required for P1 proteinase activity of Wheat streak mosaic virus (WSMV) was mapped using a series of templates with nested 3'-truncations or 5'-deleti...

Phylogenomic evidence suggested that recombination is an important evolutionary force for potyviruses, one of the larger families of plant RNA viruses. However, mixed-genotype potyvirus infections are marked by low levels of cellular coinfection, precluding template switching and recombination events between virus genotypes during genomic RNA replication. To reconcile these conflicting observat...

Infections by plant virus generally cause disease symptoms by interfering with cellular processes. Here we demonstrated that infection of Nicotiana tabacum (N.t) by plant viruses representative of the Tobamoviridae, Potyviridae, and Potexviridae families altered accumulation of certain microRNAs (miRNAs). A correlation was observed between symptom severity and alteration in levels of miRNAs 156...

BACKGROUND The bipartite single-stranded RNA genome of Sweet potato chlorotic stunt virus (SPCSV, genus Crinivirus; Closteroviridae) encodes a Class 1 RNase III (RNase3), a putative hydrophobic protein (p7) and a 22-kDa protein (p22) from genes located in RNA1. RNase3 and p22 suppress RNA silencing, the basal antiviral defence mechanism in plants. RNase3 is sufficient to render sweetpotato (Ipo...

Superinfection exclusion (SIE) is an antagonistic interaction between identical or closely related viruses in host cells. Previous studies by us and others led to the hypothesis that SIE was elicited one more proteins encoded genomes of primary viruses. Here, we tested this using Turnip mosaic virus (TuMV), a member genus Potyvirus family Potyviridae, with significant economic consequences. To ...

Background and Aims: Celery mosaic virus (CeMV) is one of the causal agents of viral diseases in celery (Apium graveolens). CeMV is a member of the Potyvirus genus in Potyviridae family. The virus is naturally transmitted by aphids in a non-persistent manner. During growing season 2006-2007 viral disease symptoms were observed in celery fields grown in Tehran Province (Bage daneshkade, Mohamads...