Euonymus japonicus phyllosphere microbiome is significantly changed by powdery mildew.

Euonymus japonicus Thunb. is a woody and ornamental plant popular in China, Europe and North America. Powdery mildew is one of the most serious diseases that affect E. japonicus growth. In this study, the diseased and apparently healthy leaves were collected from E. japonicus planted in a greenbelt in Beijing, and the effect of powdery mildew on the epiphytic microbial community was investigated by using Illumina sequencing. The results showed that the healthy leaves (HL) harbored greater bacterial and fungal diversity than diseased leaves (DL). Furthermore, both bacterial and fungal communities in DL exhibited significantly different structures from those in HL. The relative abundance of several bacterial phyla (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 significantly affect beta-diversity of the bacterial and 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 powdery mildew will help in the development of methods for controlling plant diseases.

Phylogeny of Celastraceae tribe Euonymeae inferred from morphological characters and nuclear and plastid genes.

The phylogeny of Celastraceae tribe Euonymeae (≈ 230 species in eight genera in both the Old and New Worlds) was inferred using morphological characters together with plastid (matK, trnL-F) and nuclear (ITS and 26S rDNA) genes. Tribe Euonymeae has been defined as those genera of Celastraceae with generally opposite leaves, isomerous carpels, loculicidally dehiscent capsules, and arillate seeds (except Microtropis). Euonymus is the most diverse (129 species) and widely cultivated genus in the tribe. We infer that tribe Euonymeae consists of at least six separate lineages within Celastraceae and that a revised natural classification of the family is needed. Microtropis and Quetzalia are inferred to be distinct sister groups that together are sister to Zinowiewia. The endangered Monimopetalum chinense is an isolated and early derived lineage of Celastraceae that represents an important component of phylogenetic diversity within the family. Hedraianthera is sister to Brassiantha, and we describe a second species (Brassiantha hedraiantheroides A.J. Ford) that represents the first reported occurrence of this genus in Australia. Euonymus globularis, from eastern Australia, is sister to Menepetalum, which is endemic to New Caledonia, and we erect a new genus (Dinghoua R.H. Archer) for it. The Madagascan species of Euonymus are sister to Pleurostylia and recognized as a distinct genus (Astrocassine ined.). Glyptopetalum, Torralbasia, and Xylonymus are all closely related to Euonymus sensu stricto and are questionably distinct from it. Current intrageneric classifications of Euonymus are not completely natural and require revision.

Leaf epidermal features of 21 medicinal plants of Euonymus in China.

OBJECTIVE: To accumulate taxonomic data of the leaf epidermal features of the medicinal species of Euonymus. METHOD: Twenty-nine materials of 21 taxa (including 16 species, 4 varieties and 1 form) representing 5 sections of Euonymus are examined by using both of light microscopy and scanning electron microscopy. RESULT: The form of epidermal cells in Euonymus is usually polygonal or irregular. The stomata were anomocytic in all the species examined except E. maackii and E. bungeanus var. semipersistens. Stomatal types of all species studied may be anomocytic, anisocytic, cycolocytic or the transitional types among them. CONCLUSION: The results show that some characteristics (including cuticular membrane, shape of guard cells, inner margin of outer stomatal rim, outer stomatal rim and stomata type) of the leaf epidermis can provide some anatomical evidence for the classification. The characteristics of leaf epidermis support following treatments: E. acanthocarpus var. longipes, E. acanthocarpus var. scandens and E. acanthocarpus var. sutchuanensis should be merged into E. acanthocarpus; E. bungeanus var. semipersistens should be merged into E. maackii; E. hamiltonianus f. lanceifolius should be merged into E. hamiltonianus.