Transcript imaging and candidate gene strategy for the characterisation of Prunus/PPV interactions

Abstract

Plum pox virus (PPV), the causing agent of the sharka disease, belongs to the genus Potyvirus that contains the largest number of virus species infecting plants. The virus genome has been extensively characterised and sequenced. However, few data are available on its interactions with the host plant, Prunus. In this study, we are focusing on the cloning and characterisation of any candidate genes involved in the expression of the resistance/susceptibility trait and any polymorphic genes putatively involved in the trait variation. In order to clone candidate genes, two main approaches are currently developed: the homology cloning of genes presumed to affect the resistance/susceptibility trait and the differential screening of cDNA pools corresponding to infected and non-infected plant material. The second approach is based on the transcript imaging of the host plant response to PPV infection. Previously, it has been shown that infection by a potyvirus is associated with specific changes in host gene expression, mainly down-regulation, while the expression of some genes remained unchanged. Thereby, in the differential display approach combined to further characterisation of candidate gene expression, we aim to monitor host gene expression in response to the virus and to describe a highly regulated interaction between the Prunus host plant and the infecting Plum pox virus.

Keywords

• plum pox virus (ppv)
• sharka disease
• prunus
• genetic resistance
• tolerance
• cdna-aflp
• candidate gene