Ludwig H. Pfenning

One fungus, one name

In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice.

One fungus, one name: defining the genus Fusarium in a scientifically robust way that preserves longstanding use.

In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice.

New bioactive metabolites produced by Phomopsis cassiae, an endophytic fungus in Cassia spectabilis

Two new metabolites, ethyl 2,4-dihydroxy-5,6-dimethylbenzoate (1) and phomopsilactone (2) were isolated from Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures were elucidated by 1D and 2D NMR, MS and IR spectral data. Compounds 1 and 2 displayed strong antifungal activity against the phytopatogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as cytotoxicity against human cervical tumor cell line (HeLa), in in vitro assays.

Novel antimicrobial secondary metabolites from a Penicillium sp. isolated from Brazilian cerrado soil

Electronic Journal of Biotechnology ISSN: 0717-3458 Vol.12 No.4, Issue of October 15, 2009

Substâncias antifúngicas de Xylaria sp., um fungo endofítico isolado de Palicourea marcgravii (Rubiaceae)

Five compounds, 2-hexyl-3-methyl-butanodioic acid (1), cytochalasin D (2), 7-dechlorogriseofulvin (3), cytochalasin B (4) and griseofulvin (5), have been isolated from the endophytic fungus Xylaria sp., and their structures were elucidated on the basis of spectroscopic data. In the bioautography assay against Cladosporium cladosporioides and Cladosporium sphaerospermum, compounds 1 and 2 were found to be active while compounds 3, 4 and 5 did not show antifungal activity.

Fusarium tupiense sp. nov., a member of the Gibberella fujikuroi complex that causes mango malformation in Brazil

Fusarium tupiense, the main causal agent of mango malformation in Brazil, is described through a combination of morphological, biological and molecular markers. This new species belongs to the Gibberella fujikuroi species complex (GFSC) and has an anamorph morphologically similar to Fusarium mangiferae and F. sterilihyphosum. F. tupiense can be differentiated from other species in the G. fujikuroi species complex on the basis of sexual crosses, amplified fragment length polymorphism (AFLP) markers and partial sequences of the tef1 and tub2 genes. Female fertility for field isolates of F. tupiense appears to be low. PCR with primers specific for the mating type (MAT) alleles and sexual crosses identified this species as heterothallic with two idiomorphs. Female-fertile tester strains were developed for the identification of field strains of this species through sexual crosses.

Fungal endophytes associated with the mistletoe Phoradendron perrottettii and its host tree Tapirira guianensis

The endophytic mycobiota of leaves and stems of the mistletoe Phoradendron perrottettii and its host tree Tapirira guianensis, two physiologically connected plant species of the Brazilian savannah in southeastern Brazil, were investigated to evaluate host and organ recurrence among endophytes. Leaves and stems of P. perrottettii and leaves of T. guianensis were sampled in the dry and wet season. Stems of T. guianensis were also sampled in the wet season. Endophytes were isolated by an adapted trituration and particle filtration protocol. A total of 1,615 isolates representing 99 species and 20 sterile morphotypes were recovered; 64 morphospecies occurred as singletons. The number of isolates and species was higher in the wet season. Leaves of P. perrottettii were less densely colonized than other organs studied, but were the most species-rich. Conversely, stems of T. guianensis yielded more isolates but were less species-rich. Both plants were found to harbor similar but distinguishable endophytic assemblages. The Jaccard’s index of similarity between the fungal assemblages of both plants was 0.82, higher than found for other plants in similar habitats. The fungal species composition seemed to be influenced by the collection season and organ type, as demonstrated by multivariate correspondence analysis. Paraconiothyrium brasiliense, P. sporulosum and Verticillium leptobactrum were the dominant species in P. perrottettii. In leaves of T. guianensis, Pseudocercospora sp., Phomopsis sp. 1 and Lecanicillium psalliotae were the most frequent, while Stagonospora sp. 1 and Phomopsis sp. 1 were the dominant endophytes in its stems. The results indicated that some of the dominant endophytic taxa isolated in this study colonize different hosts and plant organs while others seem to exhibit a high degree of host or organ recurrence. This study represents the first evaluation of diversity of fungal endophytes in natural vegetation of the Brazilian savannah and contributes information about the distribution and possible specificity of endophytes in tropical dicotyledoneous plants.

Chemical and molecular characterization of Phomopsis and Cytospora-like endophytes from different host plants in Brazil.

Phomopsis and related taxa comprise important endophytic and plant pathogenic species, and are known for the production of a diverse array of secondary metabolites. Species concepts within this group based on morphological characters and assumed host specificity do not reflect phylogenetic affinities. Additional phenotypic characters, such as profiles of secondary metabolites, are needed for practical species recognition. We investigated 36 strains of Phomopsis spp. and Cytospora-like fungi, obtained as endophytes of different host plants in Brazil, using metabolite profiling based on HPLC-UV/liquid chromatography -mass spectrometry (LC-MS) combined with cluster analysis of the results. Strains were also subjected to phylogenetic analyses based on internal transcribed spacer (ITS) rDNA. Six chemotypes were identified. Chemotypes 1-5 contained Phomopsis strains, while Cytospora-like strains formed the chemotype 6. Strains of chemotype 1 typically produced alternariols, altenusin, altenuene, cytosporones, and dothiorelones. Alternariol and seven unknown compounds were consistently produced by strains of chemotype 2. Members of chemotypes 3-5 produced poor metabolite profiles containing few chemical markers. Cytospora-like endophytes (chemotype 6) produced a characteristic set of metabolites including cytosporones and dothiorelones. Bayesian and Maximum Parsimony (MP) trees classified strains of each chemotype into single phylogenetic lineages or closely related groups. Strains of chemotypes 1 and 2 formed a monophyletic group along with Diaporthe neotheicola. The remaining Phomopsis strains formed monophyletic (chemotype 4) or polyphyletic (chemotypes 3 and 5) lineages inside a large and well supported clade. Cytospora-like strains formed a monophyletic lineage located at an intermediary position between Diaporthe/Phomopsis and Valsa/Cytospora clades. The combined results show that the production of secondary metabolites by Phomopsis and related Diaporthales may be species-specific, giving support to the use of metabolite profiling and chemical classification for phenotypic recognition and delimitation of species.

VCG and AFLP analyses identify the same groups in the causal agents of mango malformation in Brazil

The causal agents of mango malformation disease in Brazil are a new Fusarium lineage in the Gibberella fujikuroi species complex and Fusarium sterilihyphosum; however information on the genetic and geographical diversity of these pathogens in Brazil is missing. Vegetative compatibility group (VCG) and amplified fragment length polymorphism (AFLP) analyses were used to measure the genetic diversity within these populations. Both techniques identified the same genetic groups. Six VCG and AFLP groups were identified amongst isolates of the new lineage from Brazil. FB-VCG 1/AFLP I was the most widespread group, found in seven of the 13 sites sampled. The second most frequent group was recovered from three sites. The remaining four groups were recovered from single-sites. We think that this lineage represents a genetically and geographically diverse indigenous population that reproduces clonally. In F. sterilihyphosum, group FS-VCG 1/AFLP VII was found at three sites in the southeast region of Brazil. FS-VCG 2/AFLP VIII contained isolates from South Africa but not from Brazil. Fusarium mangiferae isolates from India and South Africa formed one group, while isolates from Egypt and the USA formed a second group. F. sterilihyphosum at present is represented by a small population that might have been introduced only once into a restricted area. The clonal nature of the observed populations suggests that these fungi either occur naturally on indigenous hosts and have jumped to the introduced mango host (introduced in Brazil) or that they originated with mango and went through a severe population bottleneck when they were introduced to Brazil from India or Southeast Asia.

Antifungal Compounds Produced by Colletotrichum gloeosporioides, an Endophytic Fungus from Michelia champaca

In this study, eight endophytic fungi were isolated from the leaves, stems and roots of Michelia champaca. The isolates were screened and evaluated for their antifungal, anticancer and acetylcholinesterase (AChE) inhibitory activities. All of the extracts exhibited potent activity against two evaluated phytopathogenic fungi. Chemical investigation of EtOAc extracts of the endophytic fungus Colletotrichum gloeosporioides resulted in the isolation of one new compound, 2-phenylethyl 1H-indol-3-yl-acetate (1), and seven known compounds: uracil (2), cyclo-(S*-Pro-S*-Tyr) (3), cyclo-(S*-Pro-S*-Val) (4), 2(2-aminophenyl)acetic acid (5), 2(4-hydroxyphenyl)acetic acid (6), 4-hydroxy- benzamide (7) and 2(2-hydroxyphenyl)acetic acid (8). All of the compound structures were elucidated using 1D and 2D NMR and MS analyses. The antifungal and AChE inhibitory activities of compounds 1–8 were evaluated in vitro. Compound 1 exhibited promising activity against Cladosporium cladosporioides and C. sphaerospermum that was comparable to that of the positive control nystatin.