A current overview of the Papaya meleira virus, an unusual plant virus

Viruses. 2015 Apr 8;7(4):1853-70. doi: 10.3390/v7041853.

Abstract

Papaya meleira virus (PMeV) is the causal agent of papaya sticky disease, which is characterized by a spontaneous exudation of fluid and aqueous latex from the papaya fruit and leaves. The latex oxidizes after atmospheric exposure, resulting in a sticky feature on the fruit from which the name of the disease originates. PMeV is an isometric virus particle with a double-stranded RNA (dsRNA) genome of approximately 12 Kb. Unusual for a plant virus, PMeV particles are localized on and linked to the polymers present in the latex. The ability of the PMeV to inhabit such a hostile environment demonstrates an intriguing interaction of the virus with the papaya. A hypersensitivity response is triggered against PMeV infection, and there is a reduction in the proteolytic activity of papaya latex during sticky disease. In papaya leaf tissues, stress responsive proteins, mostly calreticulin and proteasome-related proteins, are up regulated and proteins related to metabolism are down-regulated. Additionally, PMeV modifies the transcription of several miRNAs involved in the modulation of genes related to the ubiquitin-proteasome system. Until now, no PMeV resistant papaya genotype has been identified and roguing is the only viral control strategy available. However, a single inoculation of papaya plants with PMeV dsRNA delayed the progress of viral infection.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Carica / immunology
  • Carica / virology*
  • Genome, Viral
  • Host-Pathogen Interactions
  • Plant Diseases / immunology
  • Plant Diseases / virology*
  • Plant Viruses / genetics*
  • Plant Viruses / physiology*
  • RNA Viruses / genetics*
  • RNA Viruses / physiology*