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Frontiers in Microbiology 2023Corm rot is the most important disease of saffron, for which fungi from several genus such as spp. spp. and spp., have been previously reported to be the pathogens....
Corm rot is the most important disease of saffron, for which fungi from several genus such as spp. spp. and spp., have been previously reported to be the pathogens. In this research, we used a combination of amplicon sequencing and traditional isolation methods to identify the causal agents, main infection source. The diversity of microbial communities in diseased saffron corms and soil decreased significantly compared with healthy corms and soil. The contents of and in healthy and diseased corms were similarly high, indicating that them were not directly related to the occurrence of corm rot. But the relative abundance of , and were significantly higher in the diseased corms than healthy ones. The abundance of increased, while the abundance of , and the endophytic beneficial bacteria decreased, which may relate to the occurrence of the disease. The co-occurrence network diagram showed that the correlation between fungal and bacterial communities was mainly positive. Plant pathogens were relatively abundant in the diseased soil, according to functional gene prediction. At the same time, we also collected 100 diseased corms from the fields in Jiande, where is known as the "hometown of saffron." All isolated pathogenic strains were identified as through morphological observation and phylogenetic tree analysis of ITS, and . To better clarify the biological characteristics of . , we cultured the isolates at different temperatures and pH values. The optimum temperature for mycelial growth and sporulation was 25°C, pH 6,carbon sources sorbitol and nitrogen sources, peptone. In short, our results suggests that was the pathogen causing corm rot in Jiande and corms other than soils are the main primary infection source. These new understanding of saffron corm rot will provide the theoretical basis for its better and efficiently management.
PubMed: 37362925
DOI: 10.3389/fmicb.2023.1188376 -
Journal of Fungi (Basel, Switzerland) Jul 2023G.L. Barron is a recognized fungal species capable of forming ericoid mycorrhiza with various positive effects on host plants; therefore, newly found and previously...
G.L. Barron is a recognized fungal species capable of forming ericoid mycorrhiza with various positive effects on host plants; therefore, newly found and previously uncharacterized strains may be valuable for heather plants' controlled mycorrhization. Characteristics of the F3860 strain were studied, i.e., mycelium growth on various nutrient media and the ability to secrete auxins and enzymes. F3860 grew rapidly on malt extract agar and potato dextrose agar. It was also able to grow on nutrient media suitable for heather plant cultivation. The presence of the flavonoids rutin and quercetin increased the mycelium growth rate compared to the control, starting from the 8th to the 13th days of cultivation. The ability to secrete auxins was confirmed with bioassay and thin-layer chromatography, and their content, as well as phytase activity, was estimated spectrophotometrically. Both in nutrient media with tryptophan and without it, F3860 secreted about 6 μg IAA/mL growth medium. F3860 possessed extracellular phytase, protease, and phenol oxidase activities. The investigation indicates F3860's promise for heather seedling inoculation as an approach to increase their fitness.
PubMed: 37504716
DOI: 10.3390/jof9070728 -
World Journal of Microbiology &... Oct 2023The continuous cropping obstacle is the main factor in leading to difficulty in American ginseng replanting. The dormant microbiota in the soil may be the cause of...
The continuous cropping obstacle is the main factor in leading to difficulty in American ginseng replanting. The dormant microbiota in the soil may be the cause of American ginseng disease and eventually caused continuous cropping obstacles, but there are few studies on the dynamic changes of soil microenvironment after American ginseng planting. In this study, we tracked short-term variation in physicochemical properties, enzyme activities, and fungal communities over time-series in soils with continuous cropping obstacle under crop rotation and probiotic Bacillus treatments. Furthermore, we examined the relationships between the important fungal compositions and the soil properties. The results showed that sucrase, cellulase, urease and acid phosphatase activities were significantly increased, while catalase and dehydrogenase were decreased with treatments time. Rotation treatment significantly affected the diversity, dissimilarity degree and species distribution of soil fungal community with continuous cropping obstacle over a short-term. Moreover, beneficial fungal biomarkers such as Cladorrhinum, Oidiodendron, and Mariannaea were accumulated at 48 h under rotation treatments. Almost all fungal biomarkers were negatively correlated with hydrolases and positively correlated with oxidoreductases and acid phosphatase under crop rotation treatments. This study suggested that compared to probiotic Bacillus, crop rotation can significantly affect soil fungal community structure, especially the enrichment of specific potentially beneficial fungal species. Our findings provide a scientific basis for understanding the dynamic changes of fungal communities and soil properties with continuous cropping obstacle of American ginseng in initial stage of soil improvement.
Topics: Soil; Mycobiome; Bacillus; Panax; Acid Phosphatase; Biomarkers; Soil Microbiology
PubMed: 37874395
DOI: 10.1007/s11274-023-03807-w -
The Science of the Total Environment Mar 2024Anthropogenic nitrogen (N) deposition and fertilization in boreal forests frequently reduces decomposition and soil respiration and enhances C storage in the topsoil....
Anthropogenic nitrogen (N) deposition and fertilization in boreal forests frequently reduces decomposition and soil respiration and enhances C storage in the topsoil. This enhancement of the C sink can be as strong as the aboveground biomass response to N additions and has implications for the global C cycle, but the mechanisms remain elusive. We hypothesized that this effect would be associated with a shift in the microbial community and its activity, and particularly by fungal taxa reported to be capable of lignin degradation and organic N acquisition. We sampled the organic layer below the intact litter of a Norway spruce (Picea abies (L.) Karst) forest in northern Sweden after 20 years of annual N additions at low (12.5 kg N ha yr) and high (50 kg N ha yr) rates. We measured microbial biomass using phospholipid fatty-acid analysis (PLFA) and ergosterol measurements and used ITS metagenomics to profile the fungal community of soil and fine-roots. We probed the metabolic activity of the soil community by measuring the activity of extracellular enzymes and evaluated its relationships with the most N responsive soil fungal species. Nitrogen addition decreased the abundance of fungal PLFA markers and changed the fungal community in humus and fine-roots. Specifically, the humus community changed in part due to a shift from Oidiodendron pilicola, Cenococcum geophilum, and Cortinarius caperatus to Tylospora fibrillosa and Russula griseascens. These microbial community changes were associated with decreased activity of Mn-peroxidase and peptidase, and an increase in the activity of C acquiring enzymes. Our results show that the rapid accumulation of C in the humus layer frequently observed in areas with high N deposition is consistent with a shift in microbial metabolism, where decomposition associated with organic N acquisition is downregulated when inorganic N forms are readily available.
Topics: Nitrogen; Soil; Carbon; Forests; Microbiota; Soil Microbiology
PubMed: 38325494
DOI: 10.1016/j.scitotenv.2024.170741 -
Data in Brief Feb 2024Mining activities in the Zambian Copperbelt Province have led to the release of heavy metal-containing waste, causing contamination in nearby areas. Despite this...
Mining activities in the Zambian Copperbelt Province have led to the release of heavy metal-containing waste, causing contamination in nearby areas. Despite this environmental challenge, limited knowledge exists regarding the mycobiota in copper mine sites. This study investigates fungal community structure in copper(Cu) and cobalt (Co) contaminated soils around decommisioned dams in Kitwe. Metagenomic analysis of the ITSF1 gene amplicons was used for the purpose. The composition of soil fungal communities was characterized, and the findings revealed significant insights. At the phylum level, dominated the fungal profiles in the tailings (64.59%), followed by (21.30%), (4.53%), and (0.0275%). Several fungal genera, including , P, and , were more abundant in contaminated tailings soils, suggesting their potential in leaching, absorbing, and transforming heavy metals. In contrast, the reference soil at Mwekera National Forest exhibited different dominance patterns with four fungal phyla identified, with and dominating most samples. , known for forming arbuscular mycorrhizae with plants, were found in contaminated soils, while , which can serve ecological roles in various ecosystems, were also present. Notable fungal species such as , and demonstrated resilience to Cu and Co, the primary contaminants in the Copperbelt.
PubMed: 38186741
DOI: 10.1016/j.dib.2023.109951 -
Frontiers in Microbiology 2024The thermophilic fungus is a saprobe that is commonly isolated from soil. Here, we identified a Gram-positive bacteria-selective antimicrobial secondary metabolite from...
The thermophilic fungus is a saprobe that is commonly isolated from soil. Here, we identified a Gram-positive bacteria-selective antimicrobial secondary metabolite from this fungal species, harzianic acid (HA). Using strain 168 combined with dynamic bacterial morphology imaging, we found that HA targeted the cell membrane. To further study the antimicrobial activity of HA, we isolated an HA-resistant strain, strain M9015, and discovered that the mutant had more translucent colonies than the wild type strain, showed cross resistance to rifampin, and harbored five mutations in the coding region of four distinct genes. Further analysis of these genes indicated that the mutation in might be responsible for the translucency of the colonies, and mutation in for resistance to both HA and rifampin. We conclude that HA is an antimicrobial agent against Gram-positive bacteria that targets the cell membrane.
PubMed: 38348189
DOI: 10.3389/fmicb.2024.1332774