Community structure and ecological function analyses of endophytic and rhizosphere soil fungi in Kadsura coccinea

Abstract

To investigate rhizosphere soil and endophytic fungal community structure, diversity, and ecological function in Kadsura coccinea, the endophytic fungal communities from roots, stems, leaves, and rhizosphere soils of mature K. coccinea were analyzed based on ITS high-throughput sequencing technology. The results were as follows: (1) A total of 2 241 operational taxonomic units (OTUs) were obtained from 12 samples at 97% of sequence homology level. The OTUs of endophytic (root, stem and leaf) and rhizosphere soil fungi were 386, 536, 258 and 1 435, respectively, of which 18 OTUs were in common. They belonged to 10 phyla, 41 classes, 95 orders, 212 families and 367 genera. The dominant fungal communities at the phylum level in the endophytic and rhizosphere soil of K. coccinea were Ascomycota and Basidiomycota. Among them, Ascomycota accounted for 96.99% and 95.37% of the endophytic fungal community in leaves and stems, respectively. At the genus level, the saprophytic fungi Mortierella accounted for a relatively high proportion (13.5%) in the rhizosphere soil. In contrast, pathogenic fungi such as Ascomycota_unclassified and Elsinoe were mainly found in vigorously growing tissues (leaves and stems). (2) Alpha diversity analysis showed that the richness and diversity of the fungal community in the rhizosphere soil of K. coccinea were significantly higher than those in endophytic fungi. Although the abundance of endophytic fungi in stems was significantly higher than that in roots and leaves, the differences in endophytic fungal diversity among roots, stems and leaves were not significant. The principal component analysis (PCoA) revealed that the fungal community structures of leaves and stems were more similar, and those of roots and rhizosphere soils were more similar. (3) The function of fungal communities in different tissues and rhizosphere soils of K. coccinea was predicted and analyzed by using FUNGuild platform. The results showed that the rhizosphere soil fungi and endophytic fungi contained a large number of unclassified fungi. Among the functionally classified fungi, the pathotroph functional group had a higher proportion in the vigorously growing tissues. This study provides a theoretical basis for the screening and exploring of active functional fungi in K. coccinea.

Keywords

• kadsura coccinea
• high-throughput sequencing
• its
• endophytic fungi
• rhizosphere soil fungi
• diversity
• funguild