Search Results (4)

Tobacco mosaic virus (TMV) is one of the most persistent and infectious plant viruses. The substantial economic losses caused by TMV in the production of tobacco and vegetables (especially in the Solanaceae family) are prompting the introduction of innovative solutions that effectively inhibit infection by this pathogen. Biological control agents based on bacteria of the genera Pseudomonas, Bacillus, Pantoea and actinomycetes are becoming increasingly popular in the fight against TMV. Some fungi, including Fusarium spp., Trichoderma spp., Alternaria spp. and Sepedonium spp., as well as wood-rotting fungi, also exhibit high anti-TMV activity. This article presents a comprehensive review of recent scientific advances in the bioprotection of selected solanaceous crops against TMV. It provides information on the structure of the virus, its host range, pathogenicity and the severity of losses caused in pepper, tomato and tobacco production. The review characterises environmentally safe techniques involving biological control agents naturally occurring in the environment and the bioactive compounds extracted from them. It also identifies their effects on crops at the morphological, physiological and molecular levels. In addition, the manuscript outlines prospects for the future applications of beneficial micro-organisms and active compounds derived from them in the protection against TMV. Full article

Although keratinophilic fungi on avian feathers have been widely described, data from European literature are quite lacking regarding Mediterranean countries. The aim of the present study was therefore to evaluate the occurrence of fungal species on feathers of different avian species in Italy. A total of 378 feather samples from both aquatic (n = 254) and terrestrial birds (n = 124), for a total of 30 bird species, were cultured for keratinophilic fungi. Fungal isolates were recognized by their macro- and micro-scopical morphology, and results were corroborated by PCR and sequencing. Keratinophilic fungi belonging to 11 different species (Scopulariopsis brevicaulis, Chrysosporium keratinophilum, Trichophyton terrestre, Microsporum gypseum, Sepedonium sp., Chrysosporium pannorum, Myriodontium sp., Chrysosporium tropicum, Chrysosporium pruinosum, Chrysosporium luteum and Aphanoascus fulvescens) were isolated from 71 animals (18.8%). The frequency of isolation of keratinophilic species from terrestrial birds was significantly higher in waterfowl. Migratory birds in Italy have been proven to carry pathogenic fungi such as dermatophytes, (A. platyrhyncos, A. crecca, E. rubecula), besides saprophytic species. Full article

Fungal species of genus Sepedonium are rich sources of diverse secondary metabolites (e.g., alkaloids, peptaibols), which exhibit variable biological activities. Herein, two new peptaibols, named ampullosporin F (1) and ampullosporin G (2), together with five known compounds, ampullosporin A (3), peptaibolin (4), chrysosporide (5), c(Trp-Ser) (6) and c(Trp-Ala) (7), have been isolated from the culture of Sepedonium ampullosporum Damon strain KSH534. The structures of 1 and 2 were elucidated based on ESI-HRMSⁿ experiments and intense 1D and 2D NMR analyses. The sequence of ampullosporin F (1) was determined to be Ac-Trp¹-Ala²-Aib³-Aib⁴-Leu⁵-Aib⁶-Gln⁷-Aib⁸-Aib⁹-Aib¹⁰-GluOMe¹¹-Leu¹²-Aib¹³-Gln¹⁴-Leuol¹⁵, while ampullosporin G (2) differs from 1 by exchanging the position of Gln⁷ with GluOMe¹¹. Furthermore, the total synthesis of 1 and 2 was carried out on solid-phase to confirm the absolute configuration of all chiral amino acids as L. In addition, ampullosporin F (1) and G (2) showed significant antifungal activity against B. cinerea and P. infestans, but were inactive against S. tritici. Cell viability assays using human prostate (PC-3) and colorectal (HT-29) cancer cells confirmed potent anticancer activities of 1 and 2. Furthermore, a molecular docking study was performed in silico as an attempt to explain the structure-activity correlation of the characteristic ampullosporins (1–3). Full article

We present the first major survey of regional diversity, distribution and host-association of Sepedonium. Whereas the rather scarce worldwide records of this mycoparasitic fungus suggested no specific distribution pattern of most species before, we provide new evidence of endemic and specific host-parasite guilds of Sepedonium in Southern South America, including the description of a new species. The corresponding inventory was performed in temperate central Chile. The regional landscape, a mosaic of exotic timber plantations and remnants of native Nothofagus forests, facilitates a unique combination of endemic and adventitious Boletales hosts. During a two-year survey, 35 Sepedonium strains were isolated and cultured from infected basidiomata of allochthonous Chalciporus piperatus, Paxillus involutus, Rhizopogon spp. and Suillus spp., as well as from the native Boletus loyita, B. loyo, B. putidus and Gastroboletus valdivianus. Taxonomic diagnosis included morphology of conidia and conidiophores, sequences of ITS, RPB2 and EF1 molecular markers and characteristics of in vitro cultures. Phylogenetic reconstructions were performed using Bayesian methods. Four Sepedonium species could be identified and characterized, viz.: S. ampullosporum, S. chrysospermum, S. laevigatum and the newly described species S. loyorum. The most frequent species on introduced Boletales was S. ampullosporum, followed by S. chrysospermum and S. laevigatum. S. loyorum sp. nov. was found exclusively on native boletacean hosts, separated from its closest relative S. chalcipori by micromorphological and molecular attributes. Species descriptions and identification keys are provided. Ecological and biogeographical aspects of endemic and allochthonous symbiotic units consisting of mycoparasite, ectomycorrhizal fungal host and respective mycorrhizal tree are discussed. Full article