Identification of Plum pox virus Determinants Implicated in Specific Interactions with Different Prunus spp

Area of Science:

• Plant virology
• Molecular biology
• Genetics

Background:

• Plum Pox Virus (PPV) is a significant pathogen affecting Prunus species.
• Understanding PPV pathogenicity determinants is crucial for disease management.
• Two PPV isolates, pGPPV (D group) and pGPPVPS (M group), were used to study host-specific infection.

Purpose of the Study:

• To characterize the pathogenic properties of two PPV infectious clones in woody hosts.
• To identify the genetic determinants responsible for differential infection in plum and peach.
• To elucidate the molecular basis of PPV host specificity.

Main Methods:

• Infectious clones of PPV (pGPPV and pGPPVPS) were constructed and inoculated into Prunus spp. seedlings.
• Chimeric viruses were created by exchanging genomic fragments between the two clones.
• Phenotypic characterization of infection (local/systemic) was performed in plum and peach cultivars.

Main Results:

• PPV isolates exhibited differential infection capabilities in plum and peach.
• In plum, systemic infection determinants were mapped to a region encoding P3 and 6K1 proteins.
• In peach, determinants for stable infection were complex and not precisely located, excluding specific viral proteins.

Conclusions:

• PPV infection in plum and peach is controlled by distinct genetic determinants.
• The P3 and 6K1 proteins play a role in systemic infection in plum.
• Multiple viral factors likely contribute to PPV pathogenicity in peach.