•Strain 38L1 was identified as Epicoccum nigrum using molecular analyses.•E. nigrum strain 38L1 has antagonistic activity against selected fungal pathogens in vitro.•Culture filtrates produced by ...strain 38L1 inhibited F. graminearum strain PH-1.•Strain 38L1 has biocontrol efficacy against F. graminearum strain PH-1 in vitro and in vivo.•Endophyte strain 38L1 reduced the severity of Fusarium head blight under growth chamber and field conditions.
Wheat (Triticum aestivum L.) and its products constitute a major part of the daily human and animal diet. However, Fusarium head blight caused by Fusarium graminearum is one of the most devastating fungal diseases in wheat. In this study, a fungal endophyte strain 38L1 was newly isolated from leaf of maize (Zea mays L.) and identified as Epicoccum nigrum using molecular phylogenetic analysis of the rDNA internal transcribed spacer (ITS), large subunit ribosomal RNA (LSU) and beta-tubulin (TUB) gene sequences. In dual cultures and double plate assays, strain 38L1 markedly inhibited the mycelial growth of F. graminearum strain PH-1 and four other pathogenic fungi including Botrytis cinerea strain P-1, Colletotrichum gloeosporioides strain Y-3, Botrytis cinerea strain F-2, and Sclerotinia sclerotiorum strain D-4, indicating a broad antifungal activity. Besides, culture filtrates of strain 38L1 indicated a high fungicidal effect resulting in a significant reduction of mycelial growth, mycelial biomass and spore germination of F. graminearum strain PH-1. Furthermore, the application of conidial suspensions and/or culture filtrates of E. nigrum strain 38L1 with spore suspensions of F. graminearum strain PH-1 on wheat spikes resulted in a significant biocontrol efficacy of Fusarium head blight in growth chamber and field conditions. Hence, these results suggest that E. nigrum strain 38L1 could be a potential biocontrol agent against F. graminearum strain PH-1 in vitro and in vivo.
Maize leaf spot occurs worldwide and affects maize production. Maize can be infected by several pathogens causing leaf spot, such as
,
,
species,
species, etc. In the current study, 30
isolates ...recovered from symptomatic maize leaves were identified based on morphological characteristics, pathogenicity, and multilocus sequence analyses of nuLSU, ITS,
, and
. These maize isolates were grouped into five
species, including
,
,
,
, and
. Pathogenicity tests showed that all five
species could produce small ellipse- and spindle-shaped spots on maize leaves. The lesion center was grayish yellow to dark gray and surrounded by a chlorotic area. Furthermore, the
isolates exhibited high pathogenicity to 20 main maize varieties of Heilongjiang Province but showed different sensitivities to the commonly used fungicides carbendazim and tebuconazole. In addition, these
isolates showed different production capacity of pectinase, cellulase, protease, amylase, laccase, and gelatinase, but all showed high lipase activity. This is the first report globally of
,
, and
as causal agents of maize leaf spot.
was first reported as a plant pathogen.
Fossil fungal spores and other non-pollen palynomorphs (NPPs) are powerful environmental proxies in European palaeoecological and archaeological contexts. However, their application on other ...continents, and particularly in the tropics, is hampered by uncertain equivalence with morphologically similar taxa in Europe, and incomplete knowledge of their ecology in the new local contexts. Here we use fossil NPP assemblages in a 25,000-year sediment record from Lake Challa, a steep-sided crater lake near Mt. Kilimanjaro in southeastern Kenya, to assess NPP diversity in a tropical-African context and the equivalence of African taxa with their European counterparts. We recovered a total of 65 well-defined NPP types, of which 61 are fungal spores, and 42 could be linked to known taxa. We provide diagnoses and illustrations of 61 recovered taxa, 58 of which have not been documented before.
Using the Challa pollen record of past regional vegetation dynamics and two independent proxies of past temperature and rainfall, we also assessed the association of individual fungal taxa with particular species and biomes of tropical-African vegetation, and with the history of regional climate change. We often found strong correspondence between the stratigraphic distribution of individual fungal spore taxa and the occurrence of specific vegetation types. Changing climate conditions appear to have had a strong impact on the ability of fungi to play a role in the decomposition of dead plants. For fungal spore assemblages, the most prominent change in regional palaeoenvironments over the past 25,000
years occurred at the start of the wet early Holocene, following Younger Dryas drought.
Epicoccum purpurascens is common in the Glacial and Late-Glacial parts of the sequence, but shows a strong decline during the early Holocene.
Coniochaeta cf.
ligniaria occurs throughout the record but shows dramatic fluctuations that appear to relate to major changes in humidity. Correlation between fungal abundance and humidity is also observed in taxa for which the Challa region provided suitable habitat from ca. 16,500
cal.
yr
BP (e.g.,
Curvularia) or from the Late-Glacial to Holocene transition (e.g.,
Tetraploa aristata,
Dictyoarthrinium cf.
sacchari, cf.
Byssothecium, types HdV-1032 and HdV-1033, cf.
Alternaria, cf.
Brachysporium, cf.
Helminthosporium,
Spegazzinia tessarthra and cf.
Lasiodiplodia theobromae). Many of these taxa did not occur, or were rare, during both wet and dry phases of the Glacial period, suggesting an additional temperature effect on their occurrence in tropical African environments. A possibly dominant role of temperature is revealed in the stratigraphic distribution of
Acrodictys, which appears at the onset of deglacial climate warming ca. 17,500
cal.
yr
BP and remains common throughout both wet and dry phases of the Holocene. Spores of the dung-inhabiting fungus
Sporormiella occur throughout the 25,000-year record without notable fluctuations, suggesting little changes in the overall population density of large herbivores in the region.
This study targeted the fungal communities in the phyllosphere of Quercus macrocarpa and compared the fungal species richness, diversity and community composition among trees located within and ...outside a small urban center using recently developed 454 sequencing and DNA tagging. The results indicate that the fungal phyllosphere communities are extremely diverse and strongly dominated by ascomycetes, with Microsphaeropsis two Operational Taxonomic Units (OTUs); 23.6%, Alternaria (six OTUs; 16.1%), Epicoccum (one OTU; 6.0%) and Erysiphe (two OTUs; 5.9%) as the most abundant genera. Although the sequencing effort averaged 1000 reads per tree and detected nearly 700 distinct molecular OTUs at 95% internal transcribed spacer 1 similarity, the richness of the hyperdiverse phyllosphere communities could not be reliably estimated as nearly one-half of the molecular OTUs were singletons. The fungal communities within and outside the urban center differed in richness and diversity, which were lower within the urban development. The two land-use types contained communities that were distinct and more than 10% of the molecular OTUs differed in their frequency.
Chemical exploration of the total extract derived from Epicoccum nigrum Ann-B-2, an endophyte associated with Annona squamosa fruits, afforded two new metabolites, epicoccofuran A (1) and flavimycin ...C (2), along with four known compounds namely, epicocconigrone A (3), epicoccolide B (4), epicoccone (5) and 4,5,6-trihydroxy-7-methyl-1,3-dihydroisobenzofuran (6). Structures of the isolated compounds were elucidated using extensive 1D and 2D NMR along with HR-ESI-MS. Flavimycin C (2) was isolated as an epimeric mixture of its two diastereomers 2a and 2b. The new compounds 1 and 2 displayed moderate activity against B. subtilis, whereas compounds (2, 3, 5, and 6) showed significant antiproliferative effects against a panel of seven different cancer cell lines with IC
values ranging from 1.3 to 12 µM.
Grasses represent one of the Earth's most common plant groups, and natural and cultivated habitats dominated by grasses cover about 40% of the land surface. In turn, each grass species hosts multiple ...fungal species which can behave as endophytes. An analysis of the endophytic taxa identified in surveys conducted in 14 grass species showed that some of the most frequent taxa on each grass were also present across several host grasses. These taxa were Alternaria, Epicoccum, Cladosporium, Fusarium, and a few others. A similar analysis of airborne fungi surveyed at 41 different locations throughout the world showed that some of the most geographically widespread, and most locally frequent airborne fungi belonged to the same genera that are dominant endophytes in grasses (i.e. Cladosporium, Alternaria, Fusarium, etc.). Therefore, airborne spores of genera that are ubiquitous in grasses are common worldwide and attain high atmospheric concentrations. In addition, spores of the above mentioned fungi are also important respiratory allergens. Direct observation indicates that saprobic colonization and sporulation of non-systemic grass endophytes could become unrestrained when their host plant tissue dies. Subsequently, when appropriate environmental conditions favour sporulation on grass host surfaces, the natural cycle for airborne conidia initiates, and large numbers of these conidia disperse as inoculum for new endophytic infections. Therefore, the cycle of endophytism may be an important link between climate, plant biology and public health.
Display omitted
Four compounds including beauvericin, parahydroxybenzaldehyde, indole-3-carboxylic acid and quinizarin were isolated from endophytic fungus Epicoccum nigrum and their cytotoxicity, ...antibacterial and antioxidant activity were evaluated. Beauvericin had remarkable activity against two Gram-negative strains (Bacillus cereus and Salmonella typhimurium) with respective MIC values of 3.12 and 6.25μg/ml. All the compounds had weak cytotoxic effect on both normal and tumor cells. LC50 values ranged from 40.42 to 86.56μg/ml, 31.87 to 86.57μg/ml and 21.59 to 67.27μg/ml on Vero cells, THP-1 and RAW 264.7 respectively. The present study showed that these compounds could be developed for the formulation of antioxidant-rich therapeutic diets and as a therapeutic agent against bacterial infections.
PDF
