Euonymus japonicus phyllosphere microbiome issignificantlychanged by powdery mildew.

Abstract

Euonymus japonicusThunb. is a woody and ornamental plant popular in China, Europe and North America. Powderymildewis one of the mostseriousdiseases that affect E. japonicus growth. In this study, the diseasedand apparently healthyleaves were collected from E. japonicus planted ina greenbeltinBeijing, and the effect of powderymildew on the epiphytic microbial community was investigated by usingIllumina sequencing. The results showed that the healthy leaves (HL) harbored greater bacterial and fungal diversity than diseased leaves (DL). Furthermore, bothbacterialand fungalcommunities in DL exhibited significantly different structures from those in HL. The relative abundance of severalbacterialphyla (Proteobacteria and Firmicutes) and fungal phyla (Ascomycota and Basidiomycota) were altered by powdery mildew. At the genus level, most genera decreased as powdery mildew pathogen Erysiphe increased, while the genera Kocuria and Exiguobacterium markedly increased. Leaf properties, especially protein content was found to significantlyaffect beta-diversity ofthe bacterialand fungal community. Network analysis revealed that positive bacterial interactions in DL were stronger than those in HL samples. Insights into the underlying the indigenous microbial phyllosphere populations of E. japonicus response to powderymildew will help in the development of methods for controlling plant diseases.