AUTHOR=Zhang Hong , Wei Tian-Peng , Li Lin-Zhu , Luo Ming-Yan , Jia Wei-Yu , Zeng Yan , Jiang Yu-Lan , Tao Guang-Can 

TITLE=Multigene Phylogeny, Diversity and Antimicrobial Potential of Endophytic Sordariomycetes From Rosa roxburghii

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.755919

DOI=10.3389/fmicb.2021.755919

ISSN=1664-302X

ABSTRACT=<p><italic>Rosa roxburghii</italic> Tratt. is widely applied in food, cosmetics, and traditional medicine, and has been demonstrated to possess diverse bioactivities. Plant endophytic fungi are important microbial resources with great potential for application in many fields. They not only establish mutualistic symbiosis with host plants but also produce a variety of bioactive compounds. Therefore, in the present study, endophytic fungi were isolated from <italic>R. roxburghii</italic>, the diversity and antimicrobial activities were evaluated. As a result, 242 strains of endophytic Sordariomycetes were successfully isolated. Multigene phylogenetic analyses showed that these isolates included eight orders, 19 families, 33 genera. The dominant genera were <italic>Diaporthe</italic> (31.4%), <italic>Fusarium</italic> (14.4%), <italic>Chaetomium</italic> (7.9%), <italic>Dactylonectria</italic> (7.0%), <italic>Graphium</italic> (4.5%), <italic>Colletotrichum</italic> (4.1%), and <italic>Clonostachys</italic> (4.1%). For different tissues of <italic>R. roxburghii</italic>, alpha diversity analysis revealed that the diversity of fungal communities decreased in the order of root, fruit, stem, flower, leaf, and seed, and <italic>Clonostachys</italic> and <italic>Dactylonectria</italic> exhibited obvious tissue specificity. Meanwhile, functional annotation of 33 genera indicated that some fungi have multitrophic lifestyles combining endophytic, pathogenic, and saprophytic behavior. Additionally, antimicrobial activities of endophytic Sordariomycetes against <italic>Lasiodiplodia theobromae</italic>, <italic>Botryosphaeria dothidea</italic>, <italic>Colletotrichum capsici</italic>, <italic>Pyricularia oryzae</italic>, <italic>Rhizoctonia solani</italic>, <italic>Fusarium oxysporum</italic>, <italic>Pseudomonas syringae</italic>, <italic>Pantoea agglomerans</italic>, <italic>Staphylococcus aureus</italic>, <italic>Bacillus subtilis</italic>, <italic>Escherichia coli</italic>, and <italic>Pseudomonas aeruginosa</italic> were screened. Dual culture test assays showed that there were 40 different endophytic species with strong inhibition of at least one or moderate inhibition of two or more against the 12 tested strains. The results from the filter paper diffusion method suggested that extracellular metabolites may be more advantageous than intracellular metabolites in the development of antimicrobial agents. Eleven isolates with good activities were screened. In particular, <italic>Hypomontagnella monticulosa</italic> HGUP194009 and <italic>Nigrospora sphaerica</italic> HGUP191020 have shown promise in both broad-spectrum and intensity. Finally, some fungi that commonly cause disease have been observed to have beneficial biological activities as endophytic fungi. In conclusion, this study showed the species composition, alpha diversity, and lifestyle diversity of endophytic Sordariomycetes from <italic>R. roxburghii</italic> and demonstrated these isolates are potential sources for exploring antimicrobial agents.</p>