The present invention, in some embodiments thereof, relates to methods for enhancing fitness of pathogen-infected plants, and, more particularly, but not exclusively, to methods of using RNA interference for modulation of plant-pathogen resistance response gene expression. In particular, the present invention provides compositions and methods for enhancing host plant fitness and fruit yield and quality following Candidatus Liberibacter spp infection and, specifically, Candidatus Liberibacter spp infection in citrus plants and trees, as in Huang Long Bing.