ARTICLE | doi:10.20944/preprints201907.0153.v1
Online: 11 July 2019 (07:40:35 CEST)
Fungal endophytes have been found in all plants surveyed to date, yet for many fungi the function of endophytism is still unknown. The Foraging Ascomycete Hypothesis (FAH) proposes that saprotrophic fungi utilize an endophytic stage in leaves to modify dispersal. Under this hypothesis, leaves can provide food and water during time of environmental scarcity and they can transport the fungi to other substrates upon dehiscence. If the FAH is accurate, then some endophytes should have the ability to colonize saprobic substrates directly from a leaf-endophyte stage, though this has been little studied. To assess this ability, twelve surface-sterilized leaves of a tropical tree (Nectandra lineatifolia Mez) were placed directly on wood and incubated for six weeks. Fungi from the wood were subsequently cultured and identified by ITS sequences or morphology. 477 fungal isolates comprising 26 OTUs were cultured from the wood, the majority of which belong to saprotrophic genera (70.8% of OTUs, 82.3% of isolates). The mean OTU richness per leaf was 5.67. The term viaphyte (literally, “by way of plant”) is introduced and defined as fungi that colonize living leaves as endophytes and use the leaves to transfer to another substrate, such as wood, when the leaves dehisce. These results strengthen the Foraging Ascomycete Hypothesis and expose the possibility that viaphytism plays a significant role in the dispersal of fungal saprotrophs.
ARTICLE | doi:10.20944/preprints202101.0442.v1
Online: 22 January 2021 (12:07:39 CET)
Seventy-two clavarioid specimens from Johannes Rick's collection at PACA and BPI were revised. Eleven taxa are presented. Illustrations of the microstructures are provided for nine taxa. The description of Scytinopogon robustus includes information from recently collected specimens and SEM photographs of the basidiospores. A new combination, Clavulina ridleyi, is proposed.
ARTICLE | doi:10.20944/preprints202007.0218.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Solanum tuberosum; agroecosystems; high-throughput sequencing; fungal guild, fungal diversity; host specificity; potato cultivars
Online: 11 July 2020 (02:02:34 CEST)
The rhizosphere fungal community can play an important role in determining plant growth and health. In this study, using high-throughput sequencing, we investigated the fungal diversity and community composition in the roots and rhizosphere soil of 21 potato (Solanum tuberosum L.) cultivars. The samples were collected at three different sampling points. Furthermore, we assessed the differences in both diversity and composition of pathogen and saprotroph communities. In soil and roots, the fungal richness and relative abundance of pathogens and saprotrophs were mainly affected by sampling time. However, root fungal communities were also significantly affected by cultivar. The most substantial effect of cultivar was on root pathogen diversity. Moreover, the occurrence of most pathogens strongly varied among cultivars. Soil fungal community composition was primarily determined by sampling time; whereas in roots, the primary determinant was cultivar. Our results demonstrate changes in fungal communities over the potato growing season, as well as highlight the importance of potato cultivar on root fungal communities, and emphasise their importance in plant breeding.
ARTICLE | doi:10.20944/preprints202103.0677.v1
Subject: Life Sciences, Biochemistry Keywords: Candida albicans; CD137; neutrophil; fungal clearance
Online: 29 March 2021 (09:47:02 CEST)
Invasive fungal infections by Candida albicans frequently cause mortality in immunocompromised patients. Neutrophils are particularly important for fungal clearance at the early phase of infections, yet little has been known regarding which surface receptor controls neutrophil phagocytic activities during systemic C. albicans infection. CD137, which is encoded by Tnfrsf9, belongs to the tumor necrosis receptor superfamily and has been shown to regulate neutrophils in Gram-positive bacterial infection. Here, we used genetic and immunological tools to probe the involvement of CD137 signaling in innate defense mechanisms against systemic C. albicans infection. We first found that Tnfrsf9-/- mice were susceptible to C. albicans infection, whereas injection of anti-CD137 agonistic antibody protected the host from infection, suggesting that CD137 signaling is indispensable for innate immunity against C. albicans infection. Priming of isolated neutrophils with anti-CD137 antibody promoted their phagocytic and fungicidal activities through phospholipase C. In addition, injection of anti-CD137 antibody significantly augmented restriction of fungal growth in Tnfrsf9-/- mice that received WT neutrophils. In conclusion, our results demonstrate that CD137 signaling contributes to defense mechanisms against systemic C. albicans infection by promoting rapid fungal clearance whereby harmful immunopathology-induced tissue injuries are minimalized.
REVIEW | doi:10.20944/preprints201911.0392.v1
Subject: Chemistry, Medicinal Chemistry Keywords: fungal pathogens; antifungal agents; natural products
Online: 30 November 2019 (11:30:19 CET)
In this review, we discuss novel natural products discovered within the last decade that are reported to have antifungal activity against pathogenic species. Nearly a hundred natural products were identified that originate from bacteria, alga, fungi, sponges and plants. Fungi were the most prolific source of antifungal compounds discovered during the period of review. The structural diversity of these antifungal leads encompasses all the major classes of natural products including polyketides, shikimate metabolites, terpenoids, alkaloids and peptides.
ARTICLE | doi:10.20944/preprints201909.0113.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: native yeast; biocontrol; fungal pathogens; VOCs
Online: 11 September 2019 (02:55:31 CEST)
Changes in consumer expectations have led to increasing demand for novel plant protection strategies, in order to reduce the application of chemical products, reduce the occurrence of new pests and the impact that all these actions generate in the environment. In recent years there have been numerous investigations related to biological control and the use of microorganisms as new control strategies. As part of integrated disease management, antagonistic microorganisms have been investigated lately and presented great interest. Such microorganisms can be applied in conventional and in organic farming as biological control agents (BCA). Many of these microorganisms are present in the microbial ecology generating interactive associations between surrounding microorganisms. For these reasons, it has become necessary to search new natural antimicrobial agents as alternatives to synthetic and chemical products. It has been discovered that there are microorganisms, particularly yeasts, that have antagonistic activity and different mechanisms of action, indicating that they could be interesting candidates for the development of BCA. Here, we evaluate the antagonist effect of four endophytic yeast, Cryptococcus antarcticus, Aureobasidium pullulans, Cryptococcus terrestris and Cryptococcus oeirensis over the growth of Botrytis cinerea, Monilinia laxa, Penicillium expansum and Geotrichum candidum in in vitro assays (inhibition zone diameter assay and confrontation assay).The results revealed that the four yeast strains evaluated showed antagonistic activity against the phytopathogens tested, suggesting that these yeasts produce compounds capable of inhibiting the growth of fungi and, depending on the assay, the evaluated antagonist-yeasts have differential biocontrolling-effect against the postharvest pathogens tested.
REVIEW | doi:10.20944/preprints201610.0049.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: plant extracts; antifungal activity; fungal pathogens
Online: 13 October 2016 (11:50:21 CEST)
Abstract Plant fungal pathogens are frequently found as one of limiting factors for crop production. More than 10,000 species of fungi can cause disease in plants. To control the diseases, many farmers are still rely on the use of chemical fungicides, however most synthetic fungicides can cause acute toxicity, and some cause chronic toxicity as well. Thus, an appropriate technological improvement towards a more effective use of natural resources is required in agriculture to develop environmentally friendly sustainable farming system. This paper highlights the potential of extracts of tropical plants as antifungal agent to control plant fungal diseases. Information and data presented in this paper are mainly derived from selected and related references that previously published in the scientific journals. Many higher plants of tropical origin with fungicidal activities and their potential for fungal disease control of agricultural crops have been studied, however most of the studies have been done under in vitro condition. Some plant extracts showed strong antifungal activities on in vitro as well as in vivo tests, but some plant extracts showed significant antifungal activities on in vitro test, but did not obvious on in vivo tests. A great variation in antifungal activities were shown by plants extracts of different species and plant parts, in one hand, and on the other hand, variation was also observed on the responses of different fungal species to the same plant extract. Since the purpose of the use of plant extract is to control plant fungal diseases, the field trial is needed to ensure the stability of efficacy of certain plant extract. In addition, isolation and identification of active substances in the extracts is needed to assess possible mode of action and side effect of their use.
REVIEW | doi:10.20944/preprints202208.0457.v1
Subject: Life Sciences, Microbiology Keywords: mNGS; Metabarcoding; ITS; Biyoinformatic Analysis; Fungal Pathogenesis
Online: 26 August 2022 (09:50:28 CEST)
Crop output is directly impacted by plant infections (with fungi as the major pathogen), making accurate diagnosis of these threats crucial. Developing technology and multidisciplinary approaches are turning to genomic analyses in addition to traditional culture methods in diagnosing fungal plant diseases. The metagenomic next-generation sequencing (mNGS) method is preferred for genotyping identification of organisms, identification at the species level, illumination of metabolic pathways, and determination of microbiota. Moreover, the data obtained so far show that this new approach shows promise as an emerging new trend in fungal disease detection. Another approach covered by mNGS technologies, known as metabarcoding, enables use of specific markers specific to a genetic region and allows for genotypic identification by facilitating the sequencing of certain regions. Although the core concept of mNGS remains constant across applications, the specific sequencing methods and bioinformatics tools used to analyze the data do differ. In this review, we focus on how mNGS technology, including metabarcoding, is applied in fungal pathogenesis and its promising developments for the future.
ARTICLE | doi:10.20944/preprints201802.0053.v1
Subject: Medicine & Pharmacology, Other Keywords: epidemiology of fungal infections; infection burden; Uruguay
Online: 6 February 2018 (06:52:38 CET)
We aimed to estimate for the first time the burden of fungal infections in Uruguay. Data on population characteristics and underlying conditions were extracted from the National Statistics Institute, the World Bank, national registries and published articles. When no data existed, risk populations were used to estimate frequencies extrapolating from the literature. Population structure: total 3,444,006; 73% adults; 35% women younger than 50 years. Size of populations at risk: HIV infected 12,000; acute myeloid leukemia 126; hematopoietic stem cell transplantation 30; solid organ transplants 134; COPD 272,006 (19.7% of older than 40); asthma in adults 223,431 (prevalence 9%); cystic fibrosis in adults 48; tuberculosis 613 (incidence 26.2%), lung cancer 1,400 (ASR incidence 27.4). Annual incidence estimations per 100,000: 22.4 invasive aspergillosis, 16.4 candidaemia, 3.7 Candida peritonitis, 1.62 Pneumocystis jirovecii pneumonia, 0.75 cryptococcosis, severe asthma with fungal sensitisation 217, allergic bronchopulmonary aspergillosis 165, recurrent Candida vaginitis 6,323, oral candidiasis 74.5 and oesophageal candidiasis 25.7. Although some under and overestimations could have been made, we expect that at least 127,525 people suffer from serious fungal infections each year. Sporothrichosis, histoplasmosis, paracoccidioidomycosis and dermatophytosis are known to be frequent but no data are available to make accurate estimations. Given the magnitude of the burden of fungal infections in Uruguay, efforts should be made to improve surveillance, strengthen laboratory diagnosis and warrant access to first line antifungals.
ARTICLE | doi:10.20944/preprints202208.0185.v1
Subject: Life Sciences, Other Keywords: fungal systematics; Talaromyces santanderensis; cadmium; cacao rhizosphere; mycoremediation
Online: 10 August 2022 (03:29:20 CEST)
Inorganic pollutants in Colombian cocoa (Theobroma cacao L.) agrosystems cause problems in the production, quality, and exportation of this raw material. There has been an increased interest in bioprospecting studies of different fungal species focused on the biosorption of heavy metals. Furthermore, fungi constitute a valuable, profitable, ecological, and efficient natural soil resource that could be considered in the integrated management of cadmium mitigation. In this study, we report a new species of Talaromyces, isolated from cocoa soil from San Vicente de Chucurí-Colombia. The characterization of the culture was performed on six different standardized media and was distinguished by characteristic colony morphology: biverticillate and monoverticillate penicilli, acerose phialides, and slightly globose smooth-walled conidia. Culture was featured by bright yellow mycelium in young culture on CYA and CYAS medium. Colonies grew faster on Malt and Oat agar, attaining 36 and 32 mm diameter after seven days at 20 ºC. High acid production on CREA medium at 20-30 ºC was observed. Phylogenetic analysis was based on the ITS region and the RPB2, Calmodulin (CaM) and β-Tubulin genes that indicate that it is new to science and is named Talaromyces santanderensis sp. nov. This new species belongs to the Talaromyces section and is closely related to T. lentulus and related to T. soli, T. tumuli and T. pratensis (inside the T. pinophilus species complex) in the inferred phylogeny. Mycelia growth of the fungal strains was subjected to a range of 0-400 ppm Cd and incorporated into malt extract agar (MEA) in triplicates. Fungal radial growth was recorded every three days over a 13-days incubation period and In vitro cadmium tolerance tests showed a high tolerance index = 0,81 when the mycelium was exposed to 300 ppm of Cd. Results suggest T. santanderensis showed tolerance to Cd concentrations that exceed the permissible limits for contaminated soils, and it is promising for its use in bioremediation strategies to eliminate Cd from highly contaminated agricultural soils.
ARTICLE | doi:10.20944/preprints202205.0186.v1
Subject: Life Sciences, Microbiology Keywords: collections of microorganisms; data bases; fungal diversity; metabolites
Online: 13 May 2022 (09:42:11 CEST)
This material presents the results of a comparative analysis of the fungal diversity in the world system of microbial culture collections on one side with a variety of known fungal producers on the other side. The main VKM databases used are Fungal DC and Metabolites of Fungi, the central point of analysis - the fungal ability to synthesize promising metabolites for applied use. It indicates that the option of obtaining new promising strains from the collection funds is still underestimated by the scientific community. In particular it is shown that not more than 3% of the total fungal species fund contained in culture collections are used practically. The database Fungal DC developed in VKM is available on-line in www.vkm.ru and www.mycobank.org. It is possible their use will considerably expand the range of studied strains and lead to the acquisition of new scientifically significant data.
ARTICLE | doi:10.20944/preprints202009.0266.v1
Subject: Life Sciences, Microbiology Keywords: hypogenous ectomycorrhizal fungi; truffles; soil nutrient; fungal community
Online: 12 September 2020 (08:04:07 CEST)
Truffles contribute to crucial dynamics in the soil systems, being involved in plentiful ecological functions important for ecosystems. Despite this, the interactions between truffles and surrounding mycobiota remain unknown. Here, we aimed to shed light on how much truffle species could affect its surrounding soil mycobiota. Using traditional chemical analysis and Illumina ITS amplicon sequencing, we compared soil nutrients and mycobiota surrounding two truffle species: Tuber indicum (Ti) and T. pseudohimalayense (Tp) inhabit in the same Pinus armandii forest in southwestern China. Tp soil was more acidic and had higher nutrients (total C, N, P contents) than Ti soil. Fungal richness and diversity of truffle ascomata and surrounding soils were significantly higher in Tp than in Ti. Redundancy analysis showed relationships between soil fungal taxa and soil properties had changed from negative (Tp) to positive (Ti) and shifted from a moisture-driving (Tp) to a total N-driving (Ti). Overall, our results showed that the interactions between truffle and soil system had been altered with species variation, although the causative peculiarity of these associations needs to be further studied.
ARTICLE | doi:10.20944/preprints201807.0236.v2
Subject: Biology, Other Keywords: keratinophilic fungi, non-dermatophytes, fungal flora, hair, nails
Online: 18 September 2018 (15:13:05 CEST)
Background: The presence of fungal species on the surface skin and hair is a known finding in many mammalian species and humans are no exception. Superficial fungal infections are sometimes a chronic and recurring condition that affects approximately 10-20% of the world’s population. However, most species that are isolated from humans tend to occur as co-existing flora. This study was conducted to determine the diversity of fungal species isolated from the hair and nails of workers in the central region of Saudi Arabia where there are not many observational studies on the mycological species. Materials and Methods: Male workers from Riyadh, Saudi Arabia were recruited for this study and samples were obtained from their nails and hair for mycological analysis which was done using Saboraud’s agar and sterile wet soil. Fungal isolates were examined microscopically. Results: Twenty four hair samples yielded a total of 26 species from 19 fungal genera. Chaetomiumglobosum was the most commonly isolated fungal species followed by Emericellanidulans, Cochliobolusneergaardii, and Penicilliumoxalicum. Three fungal species were isolated from nail samples, namely, Alternariaalternata, Aureobasidiumpullulans, and Penicilliumchrysogenum. Most of the isolated fungal species (17 of the 26 or 65.38% of the isolated fungal species) have not been thoroughly characterised nor morphologically classified. Conclusion: This study demonstrates the presence of previously undescribed fungal species that contribute to the normal flora of the skin and its appendages and may have a role in their pathogenies.
COMMUNICATION | doi:10.20944/preprints202203.0162.v1
Subject: Medicine & Pharmacology, Other Keywords: Mucorales; pulmonary mucormycosis; hematologic malignancy; transplantation; fungal culture; histopathology
Online: 11 March 2022 (07:59:01 CET)
Cultural recovery of Mucorales from hyphae-laden tissue is poor, and the clinical implications of culture positivity are scarcely studied. Therefore, we compared clinical and histological characteristics of culture-positive and culture-negative histology-proven pulmonary mucormycosis cases among cancer patients. Histology specimens were blindly reviewed by a Thoracic Pathologist and graded on four histopathologic features: hyphal quantity, tissue necrosis, tissue invasion, and vascular invasion. Twenty cases with a corresponding fungal culture were identified; five were culture-positive, and 15 culture-negative. Although no statistically significant differences were found, culture-positive patients were more likely to exhibit a high burden of necrosis and have a high burden of hyphae but tended to have less vascular invasion than culture-negative patients. In terms of clinical characteristics, culture-positive patients were more likely to have acute myeloid leukemia (60% vs. 27%, p=0.19), a history of hematopoietic cell transplant (80% vs. 53%, p=0.31), severe lymphopenia (absolute lymphocyte count ≤500/µL, 100% vs. 73%, p=0.36), and monocytopenia (absolute monocyte count ≤100/µL, 60% vs. 20%, p=0.11). Forty-two-day all-cause mortality was comparable between culture-positive and culture-negative patients (60% and 53%, p=0.80). This pilot study represents the first comprehensive histopathological scoring method to examine the relationship between histopathologic features, culture positivity, and clinical features of pulmonary mucormycosis.
REVIEW | doi:10.20944/preprints202107.0603.v1
Subject: Life Sciences, Other Keywords: brewer’s spent grains; brewing; fungal biovalorization; food waste; malt
Online: 27 July 2021 (11:47:31 CEST)
The beer industry is a major producer of solid waste globally, primarily in the form of brewer’s spent grains (BSG), which due to its low value has historically been diverted to livestock as feed or to landfills as waste. Its high moisture content and chemical composition positions BSG as an ideal candidate for further processing with microbial fermentation, and recent research has focused on filamentous fungi and the ability of some species therein to degrade the predominant recalcitrant cellulolignin components of BSG to produce valuable compounds. Many species have been investigated to biovalorize this waste stream, including those in the genuses Aspergillus, Pennicillium, Rhyzopus, and Trichoderma, which have been used to produce a wide array of highly valuable enzymes and other functional compounds, and to increase the nutritional value of BSG as an animal feed. This review of recent developments in the application of filamentous fungi for the valorization of BSG will discuss the biochemical makeup of BSG, the biological mechanisms underlying fungi’s primacy to this application, and the current applications of fungi in this realm. As the majority of these studies are at lab-scale, the challenges to scale-up and more widespread application and will be discussed as well.
ARTICLE | doi:10.20944/preprints202102.0555.v1
Subject: Chemistry, Analytical Chemistry Keywords: Fungal chitosan; animal chitosan; wine clarification; dissolving acid comparison.
Online: 24 February 2021 (16:38:23 CET)
Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacety-lation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. Results demonstrated that, even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal, independently from the acid used for their dissolution. This suggests that physic-chemical differences in the molecular structure occur between the two chitosan categories and that this affect significantly their technologic (oenological) properties.
ARTICLE | doi:10.20944/preprints201912.0406.v1
Subject: Biology, Plant Sciences Keywords: Rhizosphere; Fungal diversity; Community structure; Wheat root rot disease
Online: 31 December 2019 (10:20:33 CET)
Background: Wheat root rot disease due to soil-borne fungal pathogens leads to tremendous yield losses worth billions of dollars worldwide every year. It is very important to study the relationship between rhizosphere fungal diversity and wheat roots to understand the occurrence and development of wheat root rot disease. Results: A significant difference in fungal diversity was observed between the diseased and healthy groups in the heading stage, but the trend was the opposite in the filling stage. The abundance of most genera with high richness decreased significantly from the heading to the filling stage in the diseased groups; the richness of approximately one-third of all genera remained unchanged, and only a few low-richness genera, such as Fusarium and Ceratobasidium, had a very significant increase from the heading to the filling stage. In the healthy groups, the abundance of most genera increased significantly from the heading to the filling stage; the abundance of some genera did not change markedly, or the abundance of very few genera increased significantly. Physical and chemical soil indicators showed that low soil pH and density, increases in ammonium nitrogen, nitrate nitrogen and total nitrogen contributed to the occurrence of wheat root rot disease. Conclusions: Our results revealed that in the early stages of disease, highly diverse rhizosphere fungi and a complex community structure can easily cause wheat root rot disease. The existence of pathogenic fungi is a necessary condition for wheat root rot disease, but the richness of pathogenic fungi is not necessarily important. The increases in ammonium nitrogen, nitrate nitrogen and total nitrogen contributed to the occurrence of wheat root rot disease. Low soil pH and soil density are beneficial to the occurrence of wheat root rot disease.
ARTICLE | doi:10.20944/preprints201908.0227.v1
Subject: Biology, Other Keywords: dermatophyte; porcupine; Erethizon, fungus; metagenomics; fungal genetics; molecular diagnostics
Online: 21 August 2019 (12:58:19 CEST)
Twelve wild North American Porcupines (Erethizon dorsatum) were diagnosed with dermatopathies while being cared for at two wildlife rehabilitation clinics. Biopsy and necropsy were performed on 7 and 5 animals respectively. Atypical dermatophytosis was diagnosed in all cases. Lesions consisted of diffuse severe epidermal hyperkeratosis and mild hyperplasia, with mild lymphoplasmacytic dermatitis, and no folliculitis. Dermatophytes were noted histologically as hyphae and spores in hair shafts, and follicular and epidermal keratin. Trichophyton sp. was grown in 5/6 animals where culture was performed, with molecular diagnosis of Arthroderma benhamiae / Trichophyton mentagrophytes in these 5 cases. Metagenomic analysis of formalin-fixed paraffin-embedded tissue samples from 3 cases identified fungi from 17 orders in phyla Basidiomycota and Ascomycota. Alteration of therapy from ketaconazole, which was unsuccessful in 4 of 5 early cases, to terbinafine or nitraconazole lead to resolution of disease and recovery to release in four subsequent animals. In all, 6 animals were euthanized or died due to dermatopathy, no cases resolved spontaneously, and 6 cases resolved with therapy. The work we present demonstrates an atypical lesion and anatomical distribution due to dermatophytosis in a series of free-ranging wild porcupines and successful development of novel techniques for extraction and sequencing nucleic acids from fungus in archival formalin-fixed paraffin-embedded animal tissue.
ARTICLE | doi:10.20944/preprints202112.0342.v1
Subject: Life Sciences, Microbiology Keywords: Allergens; Alt a 1; Alternaria; Pleosporales; fungal spores; aerobiological samplers.
Online: 21 December 2021 (13:55:09 CET)
Fungal spores are universal atmospheric components associated to allergic reactions. Alternaria (Ascomycota) is considered the most allergenic spore taxa. Alt a 1 is the major allergen of Alternaria and is present also in other Pleosporales. In this study, standard Hirst-based sampling and analyzing methods for measuring spore daily concentrations of Alternaria, Curvularia, Drechslera-Helminthosporium, Epicoccum, Leptosphaeria, Pithomyces, Pleospora and Stemphyllium (all included in the taxon Pleosporales) have been used besides two high-volume samplers, Burkard Cyclone (2017) and MCV CAV-A/mb (2019-2020), and ELISA Kits for measuring the allergen. The detection and quantification of Alt a 1 was only possible in the samples from the MCV sampler. Although Alt a 1 was better correlated with Alternaria spores than with Pleosporales spores, the three of them showed high correlations. It is shown, for the first time, a high and significant correlation of Alt a 1 with temperature, a negative one with relative humidity and no correlation with precipitation. The aerobiological monitoring of these three elements ensures the best information for understanding the affectation to allergy sufferers but, if not possible, as a minimum public health service aiming at the detection, treatment and prevention of allergy, the study of the airborne Alternaria spores should be ensured.
ARTICLE | doi:10.20944/preprints202108.0072.v1
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: IoT; Fungal disease forecast; Botrytis cinerea; Precise agriculture; Decision support
Online: 3 August 2021 (11:20:03 CEST)
This paper presents the evaluation of a fungal disease forecast model in vineyards for qualitative parameter analysis using the data from off the shelf sensors, i.e. temperature and air relative humidity, rain precipitation, and leaf wetness. The rules for the fungal disease models are digitalized as a decision support tool that serve as an indicator to farmers for the need of spraying of the chemical substances to ensure the best growing condition and suppress the level of parasites. The temperature and humidity contexts are used interchangeably in practice to detect the risk of the disease occurrence. By taking into account a number of influences on these parameters collected from the shelf sensors, new topics for research in the multidimensional field of precision agriculture emerge. In this study, the impact of the humidity is evaluated by assessing how different humidity parameters correlate with the accuracy of the Botrytis cinerea fungi forecast. Each humidity parameter has it’s own threshold that triggers the second step of the disease modeling - risk index based on the temperature. The research showed that for humidity a low-cost relative humidity sensor can detect in average 14.61% risk values, a leaf wetness sensor an additional 3.99% risk cases, and finally, a precipitation sensor will detect only an additional 0.59% risk cases.
ARTICLE | doi:10.20944/preprints202106.0257.v1
Subject: Biology, Other Keywords: Extracellular vesicles (EVs); mRNA; fungal pathogen; plant pathogen; Ustilago maydis
Online: 9 June 2021 (10:59:36 CEST)
Extracellular vesicles (EVs) can transfer diverse RNA cargo for intercellular signalling. EV-associated RNAs have been found in diverse fungi and were proposed to be relevant for pathogenesis in animal hosts. In plant-pathogen interactions, small RNAs are exchanged in a cross-kingdom RNAi warfare and EVs were considered to be a delivery mechanism. To extend the search for EV-associated molecules involved in plants-pathogen communication, we have characterised the repertoire of EV-associated mRNAs secreted by the maize smut pathogen, Ustilago maydis. For this initial survey, EVs were isolated from axenic filamentous cultures that mimic infectious hyphae. The EV-associated RNAs were resistant to degradation by RNases and the presence of intact mRNAs was evident. The set of mRNAs enriched inside EVs relative to the fungal cells are functionally distinct from those that are depleted from EVs, particularly overrepresented in metabolic enzyme activities. Intriguingly, mRNAs of some known effectors and other proteins linked to virulence were found in EVs. Furthermore, several mRNAs enriched in EVs are also upregulated during infection, suggesting that EV-associated mRNAs may participate in plant-pathogen interaction.
ARTICLE | doi:10.20944/preprints201912.0286.v1
Subject: Materials Science, Biomaterials Keywords: Moringa oleifera; bismuth nanoparticles; polyphenolics; anti-bacterial; anti-fungal; antioxidant
Online: 21 December 2019 (12:28:21 CET)
The use of plant extracts in the synthesis of metal nanoparticles is a very attractive approach in the field of green synthesis. To benefit from the potential synergy between the biological activities of the Moringa oleifera leaves extract and metallic bismuth, our study aimed at synthesizing bismuth nanoparticles using a hydroalcoholic extract of M. oleifera leaves as a means of green synthesis that yields nontoxic products and reduces the production of wasteful material. To this end, the M. oleifera leaves extract was treated with a bismuth nitrate pentahydrate solution. A color change from light brown to dark brown indicates the synthesis of bismuth nanoparticles. The total phenolic content in the M. oleifera leaves extract used was 23.0 ± 0.3 mg gallic acid equivalent/g of dried M. oleifera leaves powder. Antioxidant property of MO synthesised bismuth Nanoparticles was evaluated and in line with the extract used in the synthesis of NPs. The physical properties of the synthesized bismuth nanoparticles were characterized using UV-Vis spectrophotometer, FT-IR spectrometer, TEM, SEM, and XRD. The synthesized bismuth nanoparticles have a size in the range of 40.4-57.8 nm with amorphous morphology. Using DPPH and phosphomolybdate assays, our findings revealed that the M. oleifera leaves extract and the synthesized bismuth nanoparticles possess antioxidant properties. Using resazurin microtiter assay, we also demonstrate that the M. oleifera leaves extract and the synthesized bismuth nanoparticles exert potent anti-bacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecalis, similarly to the inhibition exerted by Moringa extract, especially against Enterococcus faecalis (MIC values for the extract: 500, 250, 250, and 250 µg/mL; MIC values for the bismuth nanoparticles: 500, 500, 500, and 250 µg/mL, respectively). Similarly, the M. oleifera leaves extract and the synthesized bismuth nanoparticles display relatively stronger anti-fungal activity against Aspergillus niger, Aspergillus flavus, Candida albicans, and Candida glabrata (MIC values for the extract: 62.5, 62.5, 125, and 250 µg/mL; MIC values for the bismuth nanoparticles: 250, 250, 62.5, and 62.5 µg/mL, respectively). Thus, the hydroalcoholic extract of M. oleifera leaves was successfully used in the synthesis of bismuth nanoparticles, showing a positive antioxidant, anti-bacterial, and anti-fungal activity. Therefore, the synthesized bismuth nanoparticles can potentially be employed in the alleviation of symptoms associated with oxidative stress and in the topic treatment of Candida infections.
ARTICLE | doi:10.20944/preprints201911.0305.v1
Subject: Life Sciences, Microbiology Keywords: Moringa oleifera; copper nanoparticles; polyphenolics; anti-bacterial; anti-fungal; antioxidant
Online: 26 November 2019 (03:45:52 CET)
The synthesis of metal nanoparticles using plant extracts is a very promising method in green synthesis. The medicinal value of Moringa oleifera leaves and the anti-microbial activity of metallic copper were combined in the present study to synthesize copper nanoparticles having a desirable added-value inorganic material. The use of a hydroalcoholic extract of M. oleifera leaves for the green synthesis of copper nanoparticles is an attractive method as it leads to the production of harmless chemicals and reduces waste. The total phenolic content in the M. oleifera leaves extract was 23.0 ± 0.3 mg gallic acid equivalent/g of dried M. oleifera leaves powder. The M. oleifera leaves extract was treated with a copper sulphate solution. A color change from brown to black indicates the formation of copper nanoparticles. Characterization of the synthesized copper nanoparticles was performed using UV-Vis spectrophotometer, FT-IR spectrometer, TEM, SEM, and XRD. The synthesized copper nanoparticles have an amorphous nature and particle size of 35.8-49.2 nm. We demonstrate that the M. oleifera leaves extract and the synthesized copper nanoparticles display considerable antioxidant activity. Moreover, the M. oleifera leaves extract and the synthesized copper nanoparticles exert potent anti-bacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (MIC values for the extract: 500, 250, 250, and 250 μg/mL; MIC values for the cooper nanoparticles: 500, 500, 500, and 250 μg/mL, respectively). Similarly, the M. oleifera leaves extract and the synthesized copper nanoparticles exert relatively more potent anti-fungal activity against Aspergillus niger, Aspergillus flavus, Candida albicans, and Candida glabrata (MIC values for the extract: 62.5, 62.5, 125, and 250 μg/mL; MIC values for the cooper nanoparticles: 125, 125, 62.5, and 31.2 μg/mL, respectively). Our study reveals that the green synthesis of copper nanoparticles using a hydroalcoholic extract of M. oleifera leaves was successful. In addition, the synthesized copper nanoparticles can be potentially employed in the treatment of various microbial infections due to their potent antioxidant, anti-bacterial, and anti-fungal activities.
ARTICLE | doi:10.20944/preprints201807.0417.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Conservation Agriculture; Durum Wheat; Faba-bean, Fungal diseases; Grain Quality
Online: 23 July 2018 (11:39:38 CEST)
Conservation agriculture (CA) could be very effective for agricultural sustainability under Mediterranean environments, where farmers rely on short rotation based on durum wheat. In this work we investigated the effect of different combination of tillage treatments and crop sequence (conventional tillage and wheat monocropping, CT-WW; conventional tillage, and wheat following faba-bean, CT-WF; zero tillage and wheat monocropping, ZT-WW; zero tillage and wheat following faba-bean, ZT-WF) on yield, grain quality traits as well as on diseases incidence and severity in durum wheat (var. Saragolla). The results of a two-years of data of a long-term experiment (7-year experiment; split-plot design) are discussed. The CA approach (ZT+WF), which induced always the highest grain yields (6.1 t ha-1 and 3.3 t ha-1 in 2016 and 2017) thanks to an increased number of spikes m-2 (296 vs 269 and 303 vs 287 spikes m-2 in 2016 and 2017, respectively) as well as to a more pronounced ear length, demonstrated significant positive influences in terms of grain quality. It promoted grain protein accumulation (12.1% for ZT+WF versus 11.4% for ZT+WW and 12.4% for ZT+WF versus 10.6% for ZT+WW in 2016 and 2017), improved gluten quality (in terms of SDS sedimentation test) and colour of the grain. The abundance of crop residues determined a higher incidence and severity of Zymoseptoria tritici leaf symptoms under CA system; nevertheless the late appearance of infection was the main reason of not affecting yield and quality traits. The presence of faba-bean (WF) in the rotation significantly reduced leaf symptoms of Z. tritici.
REVIEW | doi:10.20944/preprints202202.0029.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: Allergy; Alternaria; Aspergillus; dermatophytes; fungal allergens; immunocompetence; indoor/outdoor allergens; Malassezia.
Online: 2 February 2022 (11:30:49 CET)
Fungi kingdom comprises ubiquitous forms of life with 1.5 billion years, mostly phytopathogenic and commensal for humans and animals. However, in the presence of impaired conditions fungi may cause disease by intoxicating, infecting or sensitizing with allergy. Different genera may be implicated as etiological agents for humans and animals, with Alternaria, Aspergillus, dermatophytes like Microsporum and Trichophyton, and Malassezia as the commonly implicated. Alternaria and Malassezia stand as the most commonly associated to either allergy or infection, immediately followed by Aspergillus, while dermatophytes are usually associated to ring worm skin infection. Research in veterinary field is not much but necessary.
ARTICLE | doi:10.20944/preprints202106.0668.v1
Subject: Physical Sciences, Acoustics Keywords: Information dynamics; Multiscale analysis; Networks entropy; Network density matrix; Fungal networks
Online: 28 June 2021 (14:45:57 CEST)
Complex biological systems consist of large numbers of interconnected units, characterized by emergent properties such as collective computation. In spite of all the progress in the last decade, we still lack a deep understanding of how these properties arise from the coupling between the structure and dynamics. Here, we introduce the multiscale emergent functional state, which can be represented as a network where links encode the flow exchange between the nodes, calculated using diffusion processes on top of the network. We analyze the emergent functional state to study the distribution of the flow among components of 92 fungal networks, identifying their functional modules at different scales and, more importantly, demonstrating the importance of functional modules for information content of networks, quantified in terms of network spectral entropy. Our results suggest that the topological complexity of fungal networks guarantees the existence of functional modules at different scales keeping the information entropy, and functional diversity, high.
ARTICLE | doi:10.20944/preprints202009.0584.v1
Subject: Life Sciences, Microbiology Keywords: fungal community; gut mycobiota; diversity; ITS metabarcoding; intestinal parasites; children; Mali
Online: 24 September 2020 (12:24:53 CEST)
Eukaryotic enteric pathogens (EEP) are a public health issue in tropical areas. Yet, their interactions with the gut mycobiota remain poorly understood. We conducted a cross-sectional study in Malian children to analyze the impact of EEP on the gut fungal community. EEP were assessed by qPCR and the gut mycobiota was characterized by ITS1-2 metabarcoding in stool samples collected from 296 children. The 100 controls, in whom no EEP was detected, were compared to: a) 196 children with ≥1 EEP; b) 91 with only Blastocystis; c) 35 with only Giardia intestinalis; and d) 12 with another (<1% each) EPP. The gut fungal community structure was homogenous in each children’s group. Linear size-effect discriminant analysis highlighted five relatively more abundant species, including Fusarium longipes and Penicillium caseifulvum, in children with ≥1 EEP, whereas 28, including Aspergillus sydowii and Microdochium colombiense were more abundant in controls. Fusarium, Pyxidiophora, and Stereum abundance was higher in Blastocystis-infected children, whereas Ogataea and Allocryptovalsa were more abundant in controls. Sordariales and Mortierellales abundance was higher in Giardia intestinalis-infected children, whereas Agaricales and Capnodiales abundance was higher in controls. In conclusion, EEP do not significantly alter the gut fungal community structure, and further studies are warranted to confirm our findings that particular taxa are associated with susceptibility or resistance to specific EEP.
ARTICLE | doi:10.20944/preprints202208.0455.v1
Subject: Life Sciences, Biotechnology Keywords: Shock waves; Acoustic cavitation; Gene expression; Aspergillus niger; Cell permeabilization; Fungal germination
Online: 26 August 2022 (09:34:23 CEST)
Shock waves, as used in medicine, can induce cell permeabilization, genetically transforming filamentous fungi; however, little is known on the interaction of shock waves with the cell wall. Because of this, the selection of parameters has been empirical. We studied the influence of shock waves on the germination of Aspergillus niger, to understand their effect on the modulation of four genes related to the growth of conidia. Parameters were varied in the range reported in protocols for genetic transformation. Vials containing conidia in suspension were exposed to either 50, 100 or 200 single-pulse or tandem shock waves, with different peak pressures (approximately 42, 66 and 83 MPa). In the tandem mode, three delays were tested. To equalize the total energy, the number of tandem “events” was halved compared to the number of single-pulse shock waves. Our results demonstrate that shock waves do not generate severe cellular effects on the viability and germination of A. niger conidia. Nevertheless, increase in the aggressiveness of the treatment induced a modification in the four genes tested. Scanning electron microscopy revealed significant changes to the cell wall of the conidia. Under optimized conditions, shock waves could be used for several biotechnological applications, surpassing conventional techniques.
REVIEW | doi:10.20944/preprints202008.0672.v1
Subject: Medicine & Pharmacology, Other Keywords: breakthrough invasive fungal infections; invasive candidiasis; invasive mold infections; endemic mycoses; diagnostics
Online: 30 August 2020 (15:13:51 CEST)
Breakthrough invasive fungal infections (bIFI) cause significant morbidity and mortality. Their diagnosis can be challenging due to reduced sensitivity of conventional culture techniques, serologic tests, and PCR-based assays in patients on antifungal therapy, and their diagnosis can be delayed contributing to poor patient outcomes. In this review, we provide consensus recommendations on behalf of the European Confederation for Medical Mycology (ECMM) for the diagnosis of bIFI caused by invasive yeasts, molds, and endemic mycoses, to guide diagnostic efforts in patients receiving antifungals and support the design of future clinical trials in the field of clinical mycology. The cornerstone of lab-based diagnosis of breakthrough infections for yeast and endemic mycoses remain conventional culture, to accurately identify the causative pathogen and allow for antifungal susceptibility testing. The impact of non-culture-based methods are not well-studied for the definite diagnosis of breakthrough invasive yeast infections. Non-culture-based methods have an important role for the diagnosis of breakthrough invasive mold infections, in particular invasive aspergillosis, and a combination of testing involving conventional culture, antigen-based assays, and PCR-based assays should be considered. Multiple diagnostic modalities, including histopathology, culture, antibody and/or antigen tests and occasionally PCR-based assays may be required to diagnose breakthrough endemic mycoses. A need exists for diagnostic tests that are effective, simple, cheap, and rapid to enable the diagnosis of bIFI in patients taking antifungals.
ARTICLE | doi:10.20944/preprints201808.0268.v1
Subject: Life Sciences, Microbiology Keywords: Nicotiana tabacum; Topographic; Growth period; Fungal community composition; Genetic Diversity; ITS1 region
Online: 15 August 2018 (10:51:18 CEST)
Fungal endophytes are the most ubiquitous plant symbionts on earth and are phylogenetically diverse. Studies on the fungal endophytes in tobacco have shown that they are widely distributed in the leaves, stems, and roots, and play important roles in the composition of the microbial ecosystem of tobacco. Herein, we analyzed and quantified the endophytic fungi of healthy tobacco leaves at the seedling (SS), resettling growth (RGS), fast-growing (FGS), and maturing (MS) stages at three altitudes [600 (L), 1000 (M), and 1300 m (H)]. We sequenced the ITS region of fungal samples to delimit operational taxonomic units (OTUs) and phylogenetically characterize the communities. The result showed the number of clustering OTUs at SS, RGS, FGS and MS were greater than 170, 245, 140, and 164, respectively. At the phylum level, species in Ascomycota and Basidiomycota had absolute predominance, representing 97.8% and 2.0 % of the total number of species. We also found the number of unique fungi at the RGS and FGS stages were higher than those in the other two stages. Additionally, OTU richness was determined by calculating the Observed Species, Shannon, Simpson, Chao1, ACE, Goods coverage and PD_whole_tree indices based on the total number of species. Our results showed RGS samples had the highest diversity indices. Furthermore, we found that the diversity of fungal communities tended to decrease with increasing tobacco growth altitude. The results from this study indicated that the tobacco harbors an abundant and diverse endophytic fungal population, which provides new opportunities for exploration their potential utilization.
ARTICLE | doi:10.20944/preprints202110.0104.v1
Subject: Medicine & Pharmacology, Ophthalmology Keywords: Candida; Corneal infection; Corneal ulcer; Contact lens; Fungal infection; Fusarium; Infectious keratitis; Keratoplasty
Online: 6 October 2021 (10:45:42 CEST)
Fungal keratitis (FK) is a serious ocular infection that often poses significant diagnostic and therapeutic dilemmas. This study aimed to examine the causes, clinical characteristics, outcomes, and prognostic factors of FK in the UK. All culture-positive and culture-negative presumed FK (with complete data) that presented to Queen’s Medical Centre, Nottingham, and Queen Victoria Hospital, East Grinstead, between 2011 and 2020 were included. A total of 117 patients (n=117 eyes) with FK were included in this study. The mean age was 59.0±19.6 years (range, 4-92 years) and 51.3% patients were female. Fifty-three fungal isolates were identified from 52 (44.4%) culture-positive cases, with Candida spp. (33, 62.3%), Fusarium spp. (9, 17.0%), and Aspergillus spp. (5, 9.4%) being the most common organisms. Ocular surface disease (60, 51.3%), prior corneal surgery (44, 37.6%), and systemic immunosuppression (42, 35.9%) were the three most common risk factors. Hospitalisation for intensive treatment was required for 95 (81.2%) patients, with a duration of 18.9±16.3 days. Sixty-six (56.4%) patients required additional surgical interventions for eradicating the infection. Emergency therapeutic/tectonic keratoplasty was performed in 29 (24.8%) cases, though 13 (44.8%) of them failed at final follow-up. The final corrected-distance-visual-acuity (CDVA) was 1.67±1.08 logMAR. Multivariable logistic regression analyses demonstrated increased age, large infiltrate size (>3mm), and poor presenting CDVA (<1.0 logMAR) as significant negative predictive factors for poor visual outcome (CDVA of <1.0 logMAR) and poor corneal healing (>60 days of healing time or occurrence of corneal perforation requiring emergency keratoplasty; all p<0.05). In conclusion, FK represents a difficult-to-treat ocular infection that often results in poor visual outcome, with a high need for surgical interventions. Innovative treatment strategies are urgently required to tackle this unmet need.
ARTICLE | doi:10.20944/preprints202009.0020.v1
Subject: Chemistry, Applied Chemistry Keywords: Omega-3 ethyl esters; monkfish liver oil; COSMO-RS, fungal resting cells; selectivity.
Online: 2 September 2020 (03:13:05 CEST)
The search for economical and sustainable sources of PUFAs within the framework of the circular economy is encouraged by their proven beneficial effects on health. The extraction of monkfish liver oil (MLO) for the synthesis of omega-3 ethyl esters was performed evaluating two blending systems and four green solvents. Moreover, the potential solubility of the MLO in green solvents was studied using the predictive simulation software COSMO-RS. The production of the ethyl esters was performed by one or two step reactions. Novozym 435, two resting cells (Aspergillus flavus and Rhizopus oryzae) obtained in our laboratory and mix of them were used as biocatalysts in a solvent-free system. The yields for Novozym 435, R. oryzae and A. flavus in the one-step esterification were 63%, 61% and 46%, respectively. The hydrolysis step in the two-step reaction led to 83%, 88% and 93% of free fatty acids (FFA) for Novozym 435, R. oryzae and A. flavus respectively. However, Novozym 435 showed the highest yield in the esterification step (85%) followed by R. oryzae (65%) and A. flavus (41%). Moreover, selectivity in front of polyunsaturated fatty acids of R. oryzae lipase was evidenced, since it did slightly esterified docosahexaenoic acid (DHA) in all the esterification reactions tested.
ARTICLE | doi:10.20944/preprints201710.0101.v1
Subject: Materials Science, Polymers & Plastics Keywords: single-polymer composite; bioreactor; textile reactor; fungal cultivation; economic analysis; polyamide; polyvinyl chloride
Online: 16 October 2017 (06:08:20 CEST)
All-polyamide composite coated fabric (APCCF) materials were developed and used as the material of construction of textile bioreactors as a replacement of traditional costly steel-/concreate-based bioreactors. Then, APCCF-bioreactor was used to cultivate filamentous fungus Neurospora intermedia to produce ethanol and fungal biomass. The results showed similar performance of the fungus cultivated in stain-less steel bioreactors. Techno-economical analysis for a 5000-m3 APCCF bioreactor for fermentation facility would lead to a reduction of the annual production cost of the facility by $128,000,000 compared to similar stainless-steel processes. The comparative analyses (including mechanical and morphological analyses, density measurements and techno-economical analysis) revealed that the APCCF is a better candidate for material of construction of the textile bioreactor. The APCCF is a 100% recyclable single polymer composite which was prepared from textile production line waste.
ARTICLE | doi:10.20944/preprints202104.0662.v1
Subject: Biology, Anatomy & Morphology Keywords: Aesculus hippocastanum; insect pest; fungal disease; invasive species; leaf damage; model; competition; urban environment
Online: 26 April 2021 (12:13:43 CEST)
The horse chestnut leaf miner Cameraria ohridella (Lepidoptera: Gracillariidae) is an invasive pest of horse chestnut and has spread through Europe since 1985. The horse chestnut leaf blotch Guignardia aesculi (Botryosphaeriales: Botryosphaeriaceae) is a fungal disease that also seriously damages horse chestnut trees in Europe. The interaction between the leaf miner and the fungus has not yet been sufficiently described. Therefore, the aim of the present study was to assess leaf damage inflicted to horse chestnut by both C. ohridella and G. aesculi during the vegetation season and to model their interaction. The damage to leaf area was measured monthly from May to September 2013 in České Budějovice, the Czech Republic. A simple phenomenological model describing the expected dynamics of the two species was developed. The study revealed a significant effect of sampling site and sampling period on the damage caused by both the pest and the fungus. The mathematical model indicates that infestation by C. ohridella is more affected by G. aesculi than vice versa. The possible mechanisms affecting the relationship between G. aesculi and C. ohridella are discussed.
REVIEW | doi:10.20944/preprints202010.0639.v1
Subject: Life Sciences, Biochemistry Keywords: Plants; polyamines; abiotic stresses; biotic stresses; transgenic plants; Plant-pathogen interaction; Plants-fungal interaction
Online: 30 October 2020 (13:10:51 CET)
The biotic and abiotic stresses are the main causes of the loss of agricultural crops productivity, their normal growth and development in the environment. It has been calculated that two-thirds of the major crops are frequently lost due to adverse environmental conditions. The productivity of crops under unfavorable environmental stresses is apparently the main challenge to the breeders and farmers where polyamines (PAs) play diverse roles in environmental stimuli. PAs (putrescine, spermidine, and spermine) are low molecular weight positively charge compounds have the active potential power to negative charge molecules (DNA, RNA, and proteins) is widely distributed in all living organisms. Evidence showed that PAs contribute a lot of different physiological and biological functions, such as cell growth and development, controlling the cell cycle, involve in gene expression, cell signaling, replication, transcription, translation, and membrane stabilization. Naturally occurring polyamines activity acuminated to their involvement with different biotic and abiotic stresses and contribute to the survival of the plant in the environment. Here, we have described the potential mechanisms, synthesis, and various roles of PAs during stresses tolerant and disease resistance.
Subject: Biology, Other Keywords: endosome; exosome; extracellular vesicles; fungal RNA biology; membrane trafficking; RNA transport; RNA recognition motif
Online: 21 January 2020 (03:26:40 CET)
Membrane-coupled RNA transport is an emerging theme in fungal biology. This review focuses on the RNA cargo and mechanistic details of transport via two inter-related sets of organelles: endosomes and extracellular vesicles for intra- and intercellular RNA transfer. Simultaneous transport and translation of messenger RNAs (mRNAs) on the surface of shuttling endosomes is a conserved process pertinent to highly polarised eukaryotic cells, such as hyphae or neurons. Here we detail the endosomal mRNA transport machinery components and mRNA targets of the core RNA-binding protein Rrm4. Extracellular vesicles (EVs) are newly garnering interest as mediators of intercellular communication, especially between pathogenic fungi and their hosts. Landmark studies in plant-fungus interactions indicate EVs as a means of delivering various cargos, most notably small RNAs (sRNAs), for cross-kingdom RNA interference. Recent advances and implications of the nascent field of fungal EVs are discussed and potential links between endosomal and EV-mediated RNA transport are proposed.
ARTICLE | doi:10.20944/preprints202002.0249.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Fungal diversity; Saccharomyces; genetic diversity; glyphosate-based herbicides; copper-based fungicides; RoundUp Ready™ corn; phylogenetics
Online: 17 February 2020 (15:37:11 CET)
Saccharomyces cerevisiae are a phenotypically diverse species that adapt to a wide variety of environments by exploiting standing genetic diversity and selecting for advantageous mutations. Glyphosate and copper-based herbicides/ fungicides affect non-target organisms, these incidental exposures can impact microbial populations. In this study, glyphosate resistance was found in the historical collection of yeast which was collected over the last century, but only in yeast isolated after the introduction of glyphosate. The highest glyphosate-resistant yeasts were isolated from agricultural sites. However, herbicide application at these sites was not recorded. In an effort to assess glyphosate resistance and impact on non-target microorganisms, yeast were harvested from 15 areas with known herbicidal histories, including an organic farm, conventional farm, remediated coal mine, suburban locations, state park, and a national forest. Yeast representing 23 genera were isolated from 237 samples of plant, soil, spontaneous fermentation, nut, flower, fruit, feces, and tree material samples. Saccharomyces, Candida, Metschnikowia, Klyveromyces, Hanseniaspora, and Pichia were other genera commonly found across our sampled environments. Managed areas had less species diversity and at the brewery, only Saccharomyces and Pichia were isolated. A conventional farm growing RoundUp Ready™ corn had the lowest phylogenetic diversity and the highest glyphosate resistance. The mine was sprayed with multiple herbicides including a commercial formulation of glyphosate; however, the yeast did not have elevated glyphosate resistance. In contrast to the conventional farm, the mine was exposed to glyphosate only one year prior to sample isolation. Glyphosate resistance is an example of the anthropogenic selection of nontarget organisms.
ARTICLE | doi:10.20944/preprints201906.0074.v1
Subject: Life Sciences, Microbiology Keywords: agrobacterium tumefaciens-mediated transformation; citrus fruit; metal ion chelators; fruit-fungal interaction; transcription factor; virulence; protease inhibitors
Online: 10 June 2019 (09:56:16 CEST)
Penicillium digitatum is the major postharvest pathogen of citrus fruit under Mediterranean climate conditions. In the present work, we have addressed the study of the role of P. digitatum’s proteases in virulence following two complementary approaches. In a first approach, we have undertaken the functional characterization of the P. digitatum prtT gene, which codes for a transcription factor previously shown to regulate extracellular proteases in other filamentous fungi. Deletion of prtT caused a significant loss in secreted protease activity during in vitro growth assays. However, there was no effect on virulence. Gene expression of the two major secreted acid proteases was barely affected in the ΔprtT deletant during infection of citrus fruit. Hence, no conclusion could be drawn on the role of these secreted acidic proteases on the virulence of P. digitatum. In a second approach, we have studied the effect of different protease inhibitors and chelators in virulence. Co-inoculation of citrus fruit with P. digitatum conidia and a cocktail of protease inhibitors resulted in almost a complete absence of disease development. Analysis of individual inhibitors revealed that the metalloprotease inhibitor 1,10-phenanthroline was responsible for the observed effect. The application of metal ions reverted the protective effect caused by the metallopeptidase inhibitor. These results may set the basis for the development of new alternative treatments to combat this important postharvest pathogen.
ARTICLE | doi:10.20944/preprints202105.0246.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: agriculture 4.0; chlorophyll; early diagnosis; fungal tree pathogens; mycology; plant disease; plant pathology; smart viticulture; vegetation indices; wine grapes
Online: 11 May 2021 (14:21:25 CEST)
The Armillaria genus represents one of the most common causes of chronic root rot disease in woody plants. The disease damage prompt assessment is crucial for pest management. However, the disease detection current methods are limited at the field scale. Therefore, an alternative approach that can enhance or supplement traditional techniques is needed. In this study, we investigated the potential of hyperspectral methods to identify the changes between fungi-infected and uninfected plants of Vitis vinifera in early detecting the Armillaria disease. The hyperspectral imaging sensor Specim-IQ was used to acquire images of leaves of the Teroldego Rotaliano grapevine cultivar. We analysed three groups of plants: healthy, asymptomatic, and diseased. Highly significant differences were found in the Near infrared (NIR) spectral region with a decreasing pattern from healthy to diseased plants attributable to internal leaf structure changes. Asymptomatic plants emerged from the other groups due to a smaller reflectance in the red-edge spectrum (around 705nm). Hypothetically associated with the presence of secondary metabolites involved in plant defence strategy. Furthermore, significant differences were observed in the wavelengths close to 550 nm in diseased plants versus asymptomatic. We used linear discriminant analysis from a machine learning context to classify the leaves based on the most significant variables (vegetation indices and single bands), with resulting overall accuracies of 85% and 84% respectively in healthy vs. diseased and healthy vs. asymptomatic. To our knowledge, this study represents the first report on the possibility of using hyperspectral data for root rot disease diagnosis on woody plants. Although further validation studies are required, it appears that the spectral reflectance technique, possibly implemented on unmanned aerial vehicles (UAV), could be a promising tool for a cost-effective, non-destructive method of Armillaria disease early diagnosis and mapping in the field, contributing to a significant step forward in precision viticulture.
REVIEW | doi:10.20944/preprints202201.0351.v1
Subject: Biology, Forestry Keywords: Ash; ash dieback; disease management; Fraxinus excelsior; fungal plant pathogen; Hymenoscyphus fraxineus; mycology; plant pathology; plant pathogen; plant science; tree disease
Online: 24 January 2022 (11:50:43 CET)
Ash trees have considerable economic, cultural and environmental value on the island of Ireland. However, European ash (Fraxinus excelsior L.) is currently under threat from the invasive ascomycete pathogen Hymenoscyphus fraxineus. This pathogen is the causal agent of ash dieback disease, which was initially reported in Poland in 1992. Hymenoscyphus fraxineus has since spread across Europe and the first recorded case of the disease on the island of Ireland was in 2012 at a forestry plantation in Co. Leitrim. The pathogen is now present in all 26 counties in Ireland and 6 counties in Northern Ireland, and it is considered unfeasible to eradicate. The spread of ash dieback disease is reflected in recent policy changes, which focus on management rather than eradication strategies. Since the first formal description of H. fraxineus in 2006, considerable research efforts have been made by the international scientific community to understand the biology of the pathogen and to develop management strategies against it. This review provides an update of current knowledge of H. fraxineus biology and infection. We then explore examples of mitigation techniques that have been trialled in Europe, in order to identify strategies that are feasible for disease management at a local level on the island of Ireland. Finally, we outline five key avenues of research that have the potential to provide breakthroughs in methods to protect valuable F. excelsior resources.
Subject: Biology, Animal Sciences & Zoology Keywords: feminine hygiene; feminine gel wash; lactic acid; vulvar skin pH; vulvar microbiome; skin microflora; vulvovaginal environment; bacterial 16S rRNA gene; fungal ITS
Online: 9 December 2019 (03:53:52 CET)
Background: While intimate feminine hygiene products are widely used by women as part of daily cleansing routines, little is known about how these products impact the vulvovaginal area and its microbiome stability. A novel gel wash containing lactic acid (pH 4.2) for external daily use was formulated to provide gentle cleansing, freshness, and antimicrobial protection to maintain a healthy balance of the vulvar skin area. This 4-week clinical study assessed tolerance of the gel wash when used on the external genital area and its effects on skin hydration, vulvar skin pH, and the vulvar microbiome. After a 7-day pre-study conditioning period, 36 healthy females in 3 balanced age groups (18-29, 30-44, and 45-55 years) used the gel wash to cleanse their external genital area (mons pubis and vulva) and entire body at least once per day for 28 days. The primary endpoint wasSkin tolerance of the gel wash was assessed by the gynecologist. Effects of the gel wash on vulvar skin microbiota were studied by performing bacterial 16S rRNA and fungal ITS microbial richness and diversity analysis. Results: Based on gynecologic assessment after 28 days of use, the gel wash showed acceptable tolerance, with no signs of increased dryness, redness, edema, itching, stinging, or burning. Use of the gel wash was associated with a significant increase in both short-term (single application) and longer-term (daily use for 28 days) skin moisturization. There was no significant change in vulvar skin pH over time with daily product use, and the gel wash did not significantly affect the natural vulvar microbiome species richness or diversity for bacteria or fungi. Conclusions: Results of the study showed that this new gel wash is a mild, moisturizing cleanser that does not harm and instead maintains the natural pH and microbial diversity of vulvar skin. To our knowledge, this was the first study to assess the effect of an antimicrobial feminine gel wash on the natural pH and vulvar microbiome habitat of the skin using bacterial 16S rRNA and fungal ITS genetic sequencing techniques, thereby providing a better understanding of the bacterial and fungal communities that inhabit the external vulvar area in healthy women.