Planta Med 2011; 77 - P_12
DOI: 10.1055/s-0031-1273541

Antifungal Activity of Endophytic Fungi Associated with Two Medicinal Smalanthus Species

LH Rosa 1, N Tabanca 2, N Techen 3, DE Wedge 2, RM Moraes 3, 4, LA Walker 3
  • 1Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, P. O. Box 486, CEP 31270–901, Brazil
  • 2USDA-ARS, Natural Products Utilization Research Unit (NPURU), University of Mississippi, University, MS 38677 USA
  • 3National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, MS 38677, USA
  • 4Center for Water and Wetland Resoures, The University of Mississippi Field Station 15 Road 2078, Abbeville, MS 38601, USA

Endophytic microorganisms living in tissues of ethno-medicinal plants appear to be potential new sources of bioactive compounds because of possible chemical contribution to the host's defense. In this study, two hosts of fungal endophytes, S. sonchifolius and S. uvedalius were evaluated for potential sources of compounds with antifungal properties. The genus Smallanthus sensu Robinson includes 21 species distributed from Canada to the Andes Mountains in South America. Smallanthus sonchifolius, also known as Yacon, is the most widely studied species due to its functional properties, while S. uvedalius, the North American species had medicinal value for the North American Cherokees and Iroquois. Fungal endophytes obtained from S. sonchifolius were identified by sequence analysis of the ITS region of the rRNA genes as Cladosporium, Colletotrichum, Coniothyrium, Didymella, Fusarium/Gibberella, Nigrospora, Plectosphaerella, and Trichoderma. Ethanolic extracts were screened for antifungal activity against the phytopathogenic fungi Colletotrichum fragariae, C. gloeosporioides, and C. acutatum. A total of 21 extracts showed antifungal activity to at least against one phytopathogenic test fungi. Trichoderma asparelllum, Gibberella sp., and Fusarium oxysporum produced extracts with the most antifungal activity against the Colletotrichum test species. Our results indicate that three genera Cladosporium, Fusarium and Trichoderma are common to both S. sonchifolius and S. uvedalius. These endophytes are possible sources of bioactive antifungal compounds that might be used to develop new environmental friendly pesticides.

Acknowledgements: This work received partial support of the Fundação of Amparo the Pesquisa of the Minas Gerais (FAPEMIG) process CBB 00044/09. They provided a fellowship for L.H. Rosa during his visit to The National Center for Natural Products Research at the University of Mississippi. The authors also thank the USDA, Agricultural Research Service Specific Cooperative Agreement No. 58–6408–7-012 for the research support. The authors thank Ms. J. Linda Robertson, Ms. Ramona Pace, Ms. Xiaoning Wang, Mr. Nathan Newlon, Mr. Greg Allen and Mr. William Reid for performing biological activity tests.