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.
Highlights
Plant viruses cause many diseases of international importance and are responsible for huge losses of crop production and quality in all parts of the world
Papaya fruits with sticky disease symptoms are commercially unacceptable as the disease compromises their texture and flavor, rendering them unfit for consumption, which prevents their exportation to the international market [9]
The presence of double-stranded RNA (dsRNA) with a molecular weight similar to that associated with sticky disease was detected in samples of the Gramineae species Brachiaria decunbens, which is present in the papaya orchards that are affected by the sticky disease in the south of Bahia [15]
Summary
Plant viruses cause many diseases of international importance and are responsible for huge losses of crop production and quality in all parts of the world. Papaya viruses cause diseases of international importance with serious reductions in fruit production that may even totally destroy affected orchards. In Mexico, PRSV causes severe damage in the main papaya production states with crop losses of up to 85% [8]. Little information exists about PYLV and its economic importance for fruit production, but in some orchards the disease may have an incidence of up to 40% of the plants. The disease caused by PLDMV has low economic importance to the papaya production in Brazil [7], and in Mexico this disease has not be found.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call