Fungal endophytes are well-known for their ability to promote plant growth and hinder fungal diseases, including Fusarium head blight (FHB) caused by
. This study aimed to characterize the biocontrol ...efficacy of strain J4-3 isolated from the stem of symptomless wheat collected from Heilongjiang Province, China. It was identified as
using morphological characteristics and phylogenetic analysis of the rDNA internal transcribed spacer (ITS) and beta-tubulin (
). In a dual culture assay, strain J4-3 significantly inhibited the mycelial growth of
strain PH-1 and other fungal pathogens. In addition, wheat coleoptile tests showed that lesion symptoms caused by
were significantly reduced in wheat seedlings treated with hyphal fragment suspensions of strain J4-3 compared to the controls. Under field conditions, applying spore suspensions and culture filtrates of strain J4-3 with conidial suspensions of
on wheat spikes resulted in the significant biocontrol efficacy of FHB. In addition, wheat seedlings previously treated with spore suspensions of strain J4-3 before sowing successfully resulted in FHB reduction after the application of conidial suspensions of
at anthesis. More importantly, wheat seedlings treated with hyphal fragments and spore suspensions of strain J4-3 showed significant increases in wheat growth compared to the controls under greenhouse and field conditions. Overall, these findings suggest that
J4-3 could be a promising biocontrol agent (BCA) against
, causing FHB and a growth-promoting fungus in wheat.
A new pyronepolyene C-glucoside, named iso-D8646-2-6 (1) together with the known related compound D8646-2-6 (2), was isolated from the sponge-associated fungus Epicoccum sp. JJY40. They showed NF-κB ...inhibitory and anti-influenza A viral (H1N1) activities.
In this study, we focused on grapevine-endophyte interactions and reprogrammed secondary metabolism in the host plant due to defense against the colonization of endophytes. Thus, the transcriptional ...responses of tissue cultured grapevine seedlings (
L. cv.: Cabernet Sauvignon) to two fungal endophytes
R2-21 (Epi R2-21) and
XHYN2 (Alt XHYN2) at three different time points (6 h, 6 d, 15 d) were analyzed. As expected, a total of 5748 and 5817 differentially expressed genes (DEGs) were separately initiated in Epi R2-21 and Alt XHYN2 symbiotic tissue cultured seedlings compared to no endophyte treatment. The up-regulated DEGs at all time points in Epi R2-21- or Alt XHYN2-treated seedlings were mainly enriched in the flavonoid biosynthesis, phenylpropanoid biosynthesis, phenylalanine metabolism, stilbenoid, diarylheptanoid and gingerol biosynthesis, and circadian rhythm-plant pathways. In addition, the up-regulated DEGs at all sampling times in Alt XHYN2-treated tissue cultured seedlings were enriched in the plant-pathogen interaction pathway, but appeared in Epi R2-21 symbiotic seedlings only after 15 d of treatment. The down-regulated DEGs were not enriched in any KEGG pathways after 6 h inoculation for Epi R2-21 and Alt XHYN2 treatments, but were enriched mainly in photosynthesis-antenna proteins and plant hormone signal transduction pathways at other sampling times. At three different time points, a total of 51 DEGs (all up-regulated, 1.33-10.41-fold) were involved in secondary metabolism, and 22 DEGs (all up-regulated, 1.01-8.40-fold) were involved in defense responses in endophytic fungi symbiotic tissue cultured seedlings. The protein-protein interaction (PPI) network demonstrated that genes encoding CHS (
,
, and
) and the
gene encoding CYP73A mediated the defense responses, and might induce more defense-associated metabolites. These results illustrated the activation of stress-associated secondary metabolism in the host grapevine during the establishment of fungi-plant endophytism. This work provides avenues for reshaping the qualities and characteristics of wine grapes utilizing specific endophytes and better understanding plant-microbe interactions.
A wild adult Eurasian scops owl (Otus scops), which was unable to fly, was rescued. Physical examination revealed a sticky exudate around the glottis. Heterophilic leukocytosis was identified through ...complete blood count, and radiography revealed a marked elevated density of posterior air sacs and inner cavities in both sides of the humerus and femur. Fungal cultures of samples taken from the owl suggested a respiratory fungal infection. Through molecular typing, the fungus was identified as Epicoccum nigrum. The owl was treated with oral itraconazole and broad-spectrum antibiotics. After one month, the inner cavities of pneumatic bones were slightly distinguishable by radiography and the owl started to fly well. Two months later, the air sac and all pneumatic bones displayed normal appearance.
Production of pigments by filamentous fungi is gaining interest owing to their use as food colourants, in cosmetics and textiles, and because of the important biological activities of these ...compounds. In this context, the objectives of this study were to select pigment-producing fungi, identify these fungi based on internal transcribed spacer sequences, evaluate the growth and pigment production of the selected strains on four different media, and characterize the major coloured metabolites in their extracts. Of the selected fungal strains, eight were identified as Aspergillus sydowii (CML2967), Aspergillus aureolatus (CML2964), Aspergillus keveii (CML2968), Penicillium flavigenum (CML2965), Penicillium chermesinum (CML2966), Epicoccum nigrum (CML2971), Lecanicillium aphanocladii (CML2970) and Fusarium sp. (CML2969). Fungal pigment production was influenced by medium composition. Complex media, such as potato dextrose and malt extract, favoured increased pigment production. The coloured compounds oosporein, orevactaene and dihydrotrichodimerol were identified in extracts of L. aphanocladii (CML2970), E. nigrum (CML2971), and P. flavigenum (CML2965), respectively. These results indicate that the selected fungal strains can serve as novel sources of pigments that have important industrial applications.
Pathogens associated with wheat kernel black-point disease were recovered from symptomatic grains and identified as Cochliobolus sativus, Alternaria alternata and Fusarium graminearum. A total of ...twenty-five microbial isolates obtained from the surface of healthy grains of wheat were screened for antagonism against the isolated pathogens. The most effective antagonistic isolates were Bacillus megaterium (B5), B. amyloliquefaciens (B28), Trichoderma harzianum (T37) and Epicoccum sp. (E52). In pots, treating of wheat grains with strains B5, B28, T37 and E52 significantly improved germination and seedling growth naturally infected with the black-point pathogens. Bacillus amyloliquefaciens (strain B28) was the most efficient biocontrol agent in terms of germination, length of roots and shoots which increased by 103.2, 55.3 and 43.91%, respectively. In field trials, the antagonistic isolates improved germination and tillering of black-pointed wheat grains. Spraying wheat plants with the antagonistic isolates significantly decreased the incidence of leaf-spots and kernel black-point down to 18.7 and 2.86, respectively, with B. amyloliquefaciens (B28). In addition, grain yield was significantly increased. Strain B28 (B. amyloliquefaciens) increased the weight of 1000-kernels by 16.77% and was as effective as the fungicide Sumi-8.
•Isolation of wheat black-point pathogens C. sativus, A. alternata, F. graminearum.•Screened for antagonism of twenty-five microbial isolates inhabiting surface wheat.•B. megaterium B5, B. amyloliquefaciens B28, T. harzianum T37, E. sp. E52 were effective.•Pot, field trials increase germination, seedling, tillering, decrease spot, black point.•A great interest of biocontrol agents in plant protection for clean food production.
Aims
Different endophytic fungi were isolated and screened for their digoxin‐producing ability. Strain improvement and different culture conditions were studied for more effective production of ...digoxin.
Methods and Results
Among the isolated fungi, an isolate produced digoxin in a concentration of 2·07 mg l−1. The digoxin‐producing fungal isolate was identified as Epicoccum nigrum Link according to the morphological features and phylogenetic analyses. The potentiality of the fungal strain for production enhancement of digoxin was performed by gamma radiation mutagenesis. Gamma irradiation dose of 1000 Gy intensified the digoxin yield by five‐fold. Using this dose, a stable mutant strain with improved digoxin productivity was isolated and the stability for digoxin production was followed up across four successive generations. In the effort to increase digoxin magnitude, selection of the proper cultivation medium, addition of some elicitors to the most proper medium and several physical fermentation conditions were tested. Fermentation process carried out in malt extract autolysate medium (pH 6·5) supplemented by methyl jasmonate and inoculated with 2 ml of 6‐day‐old culture and incubated at 25°C for 10 days stimulated the highest production of digoxin to attain 50·14 mg l−1. Moreover, cytotoxicity of digoxin separated from the fungal culture was tested against five different cancer cell lines. Based on the MTT assay, digoxin inhibited the proliferation of the five different cancer cell lines and the recorded 50% inhibitory concentration ranged from 10·76 to 35·14 μg ml−1.
Conclusions
This is the first report on the production and enhancement of digoxin using fungal fermentation as a new and alternate source with high productivity.
Significance and Impact of the Study
These findings offer new and alternate sources with excellent biotechnological potential for digoxin production by fungal fermentation. Moreover, digoxin proved to be a promising anticancer agent whose anticancer potential should be assessed in prospective cancer therapy.
The antifungal activity of Origanum vulgare, Rosmarinus officinalis and Lavandula angustifolia (Lamiaceae) essential oils and biocide benzalkonium chloride was investigated against fungi isolated ...from stone (Bipolaris spicifera and Epicoccum nigrum) and wooden substrata (Aspergillus niger, Aspergillus ochraceus, Penicillium sp. and Trichoderma viride) of cultural heritage objects. Carvacrol (64.06%) was the main component of O. vulgare essential oil, while linalool (37.61%) and linalool acetate (34.86%) dominated in L. angustifolia essential oil. The main component of R. officinalis essential oil was 1.8-cineole (44.28%). To determine fungistatic and fungicidal concentrations (MIC and MFC) micro-, macrodilution and microatmosphere methods were used. Mycelial growth and spore germination of fungal isolates were inhibited with different concentrations of antifungal agents. The oil of O. vulgare and biocide benzalkonium chloride displayed the strongest antifungal activities followed by R. officinalis and L. angustifolia essential oils. MIC and MFC values obtained in microatmosphere and microdilution method for O. vulgare essential oil ranged from 0.1 to 2.0μLmL−1, while for R. officinalis and L. angustifolia ranged from 10.0 to 100.0μLmL−1. The most susceptible fungus to essential oil treatments was E. nigrum. MIC and MFC values for benzalkonium chloride ranged from 0.1 to 4.0μLmL−1. Tested isolates, A. niger and A. ochraceus, were the most susceptible for biocide treatment.
•Essential oils can be novel biocides applicable in cultural heritage conservation.•Origanum vulgare essential oil displayed the strongest antifungal activity.•Rosmarinus officinalis and Lavandula angustifolia oils showed moderate activity.•Antifungal efficacy of the biocide benzalkonium chloride has been confirmed.
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