Imp Gene Analysis for Diagnosis and Genotyping of Flavescence Dorée Related Phytoplasmas

Imp is a gene coding for the immunodominant membrane protein Imp that is supposed to be involved in host-pathogen interactions. It was identified in some 'Candidatus Phytoplasma' species and showed a considerable sequence variability. For this characteristic it can be exploited to complement conventional phytoplasma classification based on the conserved 16S rRNA gene, enhancing the differentiation of closely related phytoplasma strains. This protocol describes a method for amplification and sequence analysis of the imp gene of Flavescence dorée (FD) related phytoplasmas, that can be useful for detecting and genotyping the strains involved, for example, in the complex FD epidemiology.