title: Diversity and antifungal activity of the endophytic fungi associated with the native medicinal cactus Opuntia humifusa (Cactaceae) from the United States.
abstract: The endophytic fungal community associated with the native cactus Opuntia humifusa in the United States was investigated and its potential for providing antifungal compounds. A hundred-eight endophytic fungal isolates were obtained and identified by molecular methods into 17 different taxa of the genera Alternaria, Aureobasidium, Biscogniauxia, Cladosporium, Cryptococcus, Curvularia, Diaporthe, Epicoccum, Paraconiothyrium, Pestalotiopsis and Phoma. The most frequent species associated with O. humifusa were Alternaria sp. 3, Aureobasidium pullulans and Diaporthe sp. The fungal community of O. humifusa had a high richness and diversity; additionally, the species richness obtained indicates that the sample effort was enough to recover the diversity pattern obtained. Six extracts of endophytes showed antifungal properties and (1)H NMR analyses of the extracts of Alternaria sp. 5 Ohu 8B2, Alternaria sp. 3 Ohu 30A, Cladosporium funiculosum Ohu 17C1 and Paraconiothyrium sp. Ohu 17A indicated the presence of functional groups associated with unsaturated fatty-acid olefinic protons and fatty acid methylene and methyl protons. GC-FID analysis of these extracts confirmed the presence of a mixture of different fatty acids. The (1)H NMR analyses of Biscogniauxia mediterranea Ohu 19B extracts showed the presence of aromatic compounds. From the extract of B. mediterranea we isolated the compound 5-methylmellein that displayed moderate antifungal activity against the phytopathogenic fungi Phomopsis obscurans. Our results suggest that native medicinal cacti of the United States can live symbiotically with rich and diverse endophytic communities and may be a source of bioactive molecules, including those able to inhibit or control plant disease pathogens.
authors: Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors: Alice F
authors: AF
authors: Silva-Hughes
authors: Natural Products Utilization Research Unit, Agricultural Research Service, United States Department of Agriculture, University, MS, USA. Electronic address: dwedge@olemiss.edu.
authors: David E
authors: DE
authors: Wedge
authors: Natural Products Utilization Research Unit, Agricultural Research Service, United States Department of Agriculture, University, MS, USA.
authors: Charles L
authors: CL
authors: Cantrell
authors: Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors: Camila R
authors: CR
authors: Carvalho
authors: Natural Products Utilization Research Unit, Agricultural Research Service, United States Department of Agriculture, University, MS, USA.
authors: Zhiqiang
authors: Z
authors: Pan
authors: National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS, USA; Center for Water and Wetland Resources, University of Mississippi, Abbeville, MS, USA.
authors: Rita M
authors: RM
authors: Moraes
authors: Geosystems Research Institute, Mississippi State University, MS, USA.
authors: Victor L
authors: VL
authors: Madoxx
authors: Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address: lhrosa@icb.ufmg.br.
authors: Luiz H
authors: LH
authors: Rosa
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D044822:Biodiversity; D001688:Biological Products / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005658:Fungi / Q000737:chemistry / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D029747:Opuntia / Q000382:microbiology*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014481:United States
chemical_list: D000935:Antifungal Agents; D001688:Biological Products; D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer
keywords: Cacti; Diversity; Endophytes; Fungi; Pesticides