Ultra-sensitive detection of papaya ringspot virus using single-tube nested PCR

Area of Science:

• Plant Pathology
• Molecular Biology
• Virology

Background:

• Papaya ringspot virus (PRSV) poses a significant threat to global papaya production.
• Early detection of PRSV is crucial for effective disease management and preventing widespread outbreaks.
• Existing detection methods like RT-PCR and ELISA have limitations in sensitivity and speed.

Purpose of the Study:

• To develop and validate an ultrasensitive, single-tube nested PCR (STNP) assay for the early detection of PRSV.
• To compare the sensitivity and detection speed of the STNP assay against conventional RT-PCR and ELISA.
• To assess the utility of the STNP assay for field applications, epidemiological studies, and quarantine protocols.

Main Methods:

• Design and optimization of two nested PCR primer sets targeting the P3 gene of PRSV.
• Development of a single-tube nested PCR (STNP) protocol.
• Comparative analysis of STNP, RT-PCR, and ELISA using serial dilutions of viral RNA and infected plant samples.
• Evaluation of detection limits and time-to-detection in experimentally infected papaya plants.

Main Results:

• The developed STNP assay demonstrated higher sensitivity compared to standard RT-PCR.
• STNP successfully detected PRSV in papaya plants as early as 7 days post-inoculation.
• RT-PCR and ELISA methods detected PRSV at 14-21 days post-inoculation.
• The STNP assay could detect PRSV in asymptomatic infected plants.

Conclusions:

• The single-tube nested PCR (STNP) assay provides a highly sensitive and rapid method for early PRSV detection.
• This assay significantly advances the capability for timely identification of PRSV infections in the field.
• The STNP assay is a valuable tool for epidemiological surveillance, disease management, and strengthening quarantine protocols to protect papaya cultivation.