ARS | Publication request: Diversity and biological activities of endophytic fungi associated with micropropagated medicinal plant Echinacea purpurea (L.) Moench

Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 29, 2012
Publication Date: August 1, 2012
Citation: Rosa, L.H., Tabanca, N., Techen, N., Wedge, D.E., Pan, Z., Bernier, U.R., Becnel, J.J., Agramonte, N.M., Walker, L., Moraes, R. 2012. Diversity and biological activities of endophytic fungi associated with micropropagated medicinal plant Echinacea purpurea (L.) Moench. American Journal of Plant Sciences. 3:1105-1114.

Interpretive Summary: Various studies have demonstrated that the endophytic fungal communities associated with medicinal plants produce several bioactive compounds with different biological activities such as antimicrobial, cytotoxic, immunesuppressive and anti-parasitic to protect the host. Echinacea is the second top-selling botanical supplement in the US market due to immune modulator properties. Commercially available formulations may contain different plant parts of three fungal species (Echinacea purpurea, E. pallida, and E. angustifolia). Our study evaluates the diversity of microbial community associated with healthy E. purpurea clones and their ability to produce defense compounds. We recovered and identified thirty-nine fungal endophytes through the molecular methods in 15 distinct phylotypes. Our goal was to further study the role of endophytes in association with elite Echinacea purpurea plants, we investigated the diversity of fungal endophytes associated with micropropagated clones and their capabilities to produce defence compounds to protect its host against pathogenic fungi and herbivores.

Technical Abstract: Echinacea is one of the top ten selling medicinal herbs in Europe and United States. Commercially available formulations may contain different plant parts of three species (Echinacea purpurea, E. pallida, and E. angustifolia). Our study evaluates the diversity of microbial community associated with healthy E. purpurea clones and their ability to produce defense compounds. We recovered and identified thirty-nine fungal endophytes through the molecular methods in 15 distinct phylotypes, which were closely related to species of the following genera Ceratobasidium, Cladosporium Colletotrichum, Fusarium, Glomerella, and Mycoleptodiscus. These taxa were previously reported as decomposer and phytopathogenic fungi. The fungal community associated with two E. purpurea clones showed high richness and domi-nance indices with different distribution among plant organs. Crude extracts of fungal isolates were tested for antifungal and insecticidal biological activities. A total of 16 extracts (41%) showed antifungal properties; while just the extract of M. indicus exhibited larvicidal activity against A. aegypti. These results suggest that the symbiosis between the endo-phytic fungal community and micropropagated clones of E. purpurea was re-established after acclimatization to soil and the endophytic fungi produced compounds against phytopathogenic fungi.