The cultivable endophytic fungal community of Scutellaria baicalensis: diversity and relevance to flavonoid production by the host.

Scutellaria baicalensis (SB), a traditional Chinese medicinal plant, is widely used because of its important pharmacological activities. However, the endophytic fungi that promote flavonoid accumulation in SB remain unclear. Therefore, we analyzed the endophytic fungal community of SB and screened the endophytic fungi that might promote flavonoid synthesis in SB. ITS1/ITS4Blast was used to identify the endophytic fungi in SB. In total, 687 strains were identified in 57 genera. The dominant genus in the leaves and stems was Alternaria and that in the roots was Fusarium. Alternaria was the dominant genus in SB collected from all sites and in wild and cultivated SB. Alpha diversity indexes indicated more abundant endophytic fungi in samples from Chengde, the genuine producing area of SB, than in those from other sites. Beta diversity index analysis indicated that SB plants with closer geographical relationships showed more similar endophytic fungal community profiles. Spearman correlation analysis revealed that baicalin, wogonoside, wogonin, and oroxylin A contents were significantly correlated with the relative abundance of Alternaria. Overall, the results indicate the importance of geographical factors in influencing the endophytic fungal community of SB and suggest that the presence of Alternaria spp. might contribute to flavonoid synthesis in SB.