Typically, the detection of a plant virus within its vector is carried out on the entire insect body. This process can be a possible source of confusion in the quantification of transmissible virus particles for styletborne viruses such as Potato virus Y (PVY), since the transmissible virus fraction is the one only retained in the aphid vector's mouthparts. The objective of this study was to develop and validate the quantitative PCR method for the detection and quantification of PVY in the vector's stylet. Using a specific method based on TaqMan chemistry with higher sensitivity than conventional reverse transcription PCR, this study reveals that a significant amount of the virus is enclosed within the dissected stylets of Myzus persicae. Because this quantification only concerns the portion of the virus attached to the stylets, uniformity was observed in the recorded numbers of virus targets. This novel assay is applicable to several PVY strains as a rapid and sensitive detection method for use in PVY research and offers a convenient tool for deciphering the mechanism of Potyvirus acquisition.
Keywords: absolute quantification; transmission; virus RNA copies.