Polerovirus genomic variation.

Area of Science:

• Plant virology
• Molecular evolution
• Genomics

Background:

• Poleroviruses are single-stranded RNA viruses in the Solemo viridae family, infecting diverse plants and transmitted by aphids.
• Viral adaptation relies on genomic flexibility, with mutations often accumulating in host adaptation and vector transmission determinants.
• Key polerovirus proteins include P0 (gene silencing suppressor), CP (coat protein), and CP-RT (coat protein-read-through).

Purpose of the Study:

• To profile genomic variation across the polerovirus genome.
• To identify regions under positive selection and their role in host and vector adaptation.
• To investigate the structural properties (order/disorder) of key polerovirus proteins.

Main Methods:

• Single-nucleotide variation analysis.
• Selection analyses to detect positive selection.
• Order/disorder analysis of viral proteins.

Main Results:

• Open reading frames (ORFs) encoding P0 and the CP-RT read-through domain exhibit the highest variability and positive selection.
• Protein P0 is not disordered, while CP-RT and VPg (virus protein genome-linked) contain disordered regions.
• Disordered protein regions are associated with multifunctional proteins and multiple interaction partners.

Conclusions:

• P0, VPg, and CP-RT utilize distinct mechanisms to mediate adaptation to host plants and aphid vectors.
• These proteins contribute to the broad host and vector range observed in poleroviruses.
• Understanding polerovirus genomic variation aids diagnostics, resistance breeding, and elucidates virus-environment interactions.