Comparison of Bacterial Community of Healthy and Erwinia amylovora Infected Apples

Fire blight disease, caused by Erwinia amylovora, could damage rosaceous plants such as apples, pears, and raspberries. In this study, we designed to understand how E. amylovora affected other bacterial communities on apple rhizosphere; twig and fruit endosphere; and leaf, and fruit episphere. Limited studies on the understanding of the microbial community of apples and changes the community structure by occurrence of the fire blight disease were conducted. As result of these experiments, the infected trees had low species richness and operational taxonomic unit diversity when compared to healthy trees. Rhizospheric bacterial communities were stable regardless of infection. But the communities in endosphere and episphere were significanlty affected by E. amylovora infection. We also found that several metabolic pathways differ significantly between infected and healthy trees. In particular, we observed differences in sugar metabolites. The finding provides that sucrose metabolites are important for colonization of E. amylovora in host tissue. Our results provide fundamental information on the microbial community structures between E. amylovora infected and uninfected trees, which will contribute to developing novel control strategies for the fire blight disease.

Automated summary

This study investigated the impact of fire blight disease caused by Erwinia amylovora on bacterial communities in the rhizosphere, endosphere, and episphere of apple trees, revealing that infected trees had lower species richness and diversity compared to healthy trees. While rhizospheric bacterial communities remained stable, those in the endosphere and episphere were significantly affected by E. amylovora infection. Differences in metabolic pathways, particularly sugar metabolites, were observed between infected and healthy trees, with sucrose metabolites identified as important for colonization of E. amylovora in host tissue.