High-Throughput Sequencing Analysis of the Bacterial Community in Stone Fruit Phloem Tissues Infected by "Candidatus Phytoplasma prunorum".

"Candidatus Phytoplasma prunorum" (CPp) is a highly destructive phytopathogenic agent in many stone fruit-growing regions in Europe and the surrounding countries. In this work, we focused on documenting entire bacterial community in the phloem tissues of 60 stone fruit trees. Nested PCR and two real-time PCR assays were used to select CPp-positive (group A) and CPp-negative samples (group B). Afterwards, high-throughput amplicon sequencing was performed to assess bacterial community compositions in phloem tissues. The bacterial composition in phloem tissue consisted of 118 distinct genera, represented mainly by Pseudomonas, Acinetobacter, Methylobacterium, Sphingomonas, and Rhizobium. Statistics showed that CPp influenced the bacterial composition of infected plants (group A) and that the bacterial community depended on the geographical origin of the sample. This is the first work focusing on an analysis of the influence of CPp on the bacteria coexisting in the phloem tissues of stone fruit trees.