Causal agent of sharka disease: historical perspective and current status of Plum pox virus strains

Abstract

Knowledge of the existence of strains or types of Plum pox virus (PPV), defined as monophyletic groups of closely related isolates sharing similar properties, has gradually emerged. Early attempts illustrated both the interest and the limits of biological properties for discrimination of isolates but in the late 1970s gel‐immunodiffusion assays allowed the grouping of PPV isolates into two serogroups typified by the Dideron (D) and Marcus (M) isolates. Technical difficulties, however, limited the widespread use of this approach and only in the early 1990s, with the availability of more discriminating and higher throughput techniques, did it become clear that PPV isolates could be allocated into two major groups. This led to the description of the strains, or types, PPV‐D and PPV‐M. Following this, distant PPV isolates typifying other strains such as El Amar (PPV‐EA), Cherry (PPV‐C) or Winona (PPV‐W) were identified, as well as the widespread group of recombinants known as PPV‐Rec. Each of the six known strains or types can now be identified using a range of serological or molecular techniques. However, their evolutionary history and, in particular, the reason for the wide prevalence of the PPV‐D, ‐M and ‐Rec types relative to PPV‐EA, ‐C or ‐W is still a matter of speculation.

Putative Recombination Events and Evolutionary History of Five Economically Important Viruses of Fruit Trees Based on Coat Protein-Encoding Gene Sequence Analysis

“…PPV-Rec isolates have recently been reported to be frequent in central and eastern Europe (Glasa et al 2004), and the former Yugoslavia has been tentatively identified as the origin of PPV-Rec (Glasa et al 2005). It is noteworthy that numerous researchers focused on the C-terminus NIb gene as the major location of recombination events in PPV and considered the genetically similar coherent ensemble of isolates (PPV- Rec) to be a definitive permanent subgroup (Candresse and Cambra 2006;James and Glasa 2006). What we demonstrated here is that recombination in PPV occurs in the CP gene too.…”

Assessment of the diversity and dynamics of Plum pox virus and aphid populations in transgenic European plums under Mediterranean conditions

“…The molecular variability of the PPV genome has also been characterized by RFLP analysis (Wetzel et al 1991) and sequencing of the entire or partial genome of many isolates (Candresse et al 1994;Candrese and Cambra 2006). Taken together with serological and biological variability, PPV isolates can be clustered into six different types or strains: PPV-D (Dideron), PPV-M (Marcus), PPV-EA (El Amar), PPV-C (Cherry), PPV-W (Winona) and a recombinant type between D and M, PPV-Rec (Recombinant) (López-Moya et al 2000;Szemes et al 2001;Glasa et al 2004;James and Varga 2005;Candresse and Cambra 2006;James and Glasa 2006). Recombination was not considered a mechanism with any significant role in PPV evolution.…”

First report of plum pox virus infecting Japanese apricot (Prunus mume Sieb. et Zucc.) in Japan

“…As a result, the 243-bp fragments obtained from symptomatic Japanese apricot leaves had 100% identity with each other. These sequences had 100% identity with the corresponding sequences of PPV-D isolates reported from different parts of the world, but had relatively low identities with that of PPV-M, the most epidemic strain, and of PPV-C, the cherry strain (Candresse and Cambra 2006) (Fig. 2).…”