Characterization of Two Aggressive PepMV Isolates Useful in Breeding Programs.

Pepino mosaic virus (PepMV) causes significant economic losses in tomato crops worldwide. Since its first detection infecting tomato in 1999, aggressive PepMV variants have emerged. This study aimed to characterize two aggressive PepMV isolates, PepMV-H30 and PepMV-KLP2.

Fluorescently labelled pepino mosaic virus strains share infected tissues and colocalize in cellular aggregates reminiscent of viral replication complexes.

Mixed infections of pepino mosaic virus (PepMV) isolates from the EU and CH2 strains are frequent in tomato crops. An asymmetric antagonistic relationship has been described between these strains, making their in planta interaction worthy of study. The aim of this work was to verify if PepMV isolates labelled with fluorescent proteins recapitulate the interactions described for wild type isolates and, if so, to determine the proportion of cells infected with each isolate in single and mixed infected plants.

Transcriptome analyses unveiled differential regulation of AGO and DCL genes by pepino mosaic virus strains.

Pepino mosaic virus (PepMV) is a single-stranded (ss), positive-sense (+) RNA potexvirus that affects tomato crops worldwide. We have described an in planta antagonistic interaction between PepMV isolates of two strains in which the EU isolate represses the accumulation of the CH2 isolate during mixed infections. Reports describing transcriptomic responses to mixed infections are scant.

Determinants of Persistent Patterns of Pepino Mosaic Virus Mixed Infections.

Pepino mosaic virus (PepMV) has become a pandemic virus in tomato crops, causing important economic losses worldwide. In Spain, isolates of the EU and CH2 strains co-circulate, with PepMV-EU predominantly found in mixed infections. Simultaneous mixed infections result in an asymmetric antagonism against PepMV-CH2, but the outcome of over-infections has never been tested.

Increasing temperature alters the within-host competition of viral strains and influences virus genetic variability.

Environmental conditions can affect viral accumulation, virulence and adaptation, which have implications in the disease outcomes and efficiency of control measures. Concurrently, mixed viral infections are relevant in plants, being their epidemiology shaped by within-host virus-virus interactions. However, the extent in which the combined effect of variations in abiotic components of the plant ecological niche and the prevalence of mixed infections affect the evolutionary dynamics of viral populations is not well understood.

Implications of mixed viral infections on plant disease ecology and evolution.

Mixed viral infections occur more commonly than would be expected by chance in nature. Virus-virus interactions may affect viral traits and leave a genetic signature in the population, and thus influence the prevalence and emergence of viral diseases. Understanding about how the interactions between viruses within a host shape the evolutionary dynamics of the viral populations is needed for viral disease prevention and management.