The frequency of occurrence of pathogenic and saprotrophic fungi in pea seeds in different regions of Poland

Author(s):  
Agnieszka Pszczó³ Kowska ◽  
Adam Okorski ◽  
Gabriel Fordoñski ◽  
Agnieszka Faligowska ◽  
Ewa Kaszkowiak ◽  
...  

Field pea seeds (cv. Tarchalska) grown in different regions of Poland (Warmia and Mazury, Wielkopolska, Kujawy) were subjected to mycological analyses. Simpson’s dominance index (DI) was used in the study to determine the abundance of each fungal species in the fungal communities isolated from seeds. PCR analyses were carried out with the use of species-specific primers for Fusarium fungi isolated from pea seeds to identify Tri genes responsible for trichothecene synthesis in the growing seasons of 2011, 2012 and 2013.Saprotrophic species predominated on pea seeds cv. Tarchalska grown in various Polish regions, whereas the isolated fungal pathogens were represented by species of the genus Fusarium and Botrytis cinerea. Genes encoding the synthesis of trichothecenes, the mycotoxins produced by Fusarium fungi, were not identified in the PCR analysis. In the group of peas grown in three Polish regions (Warmia and Mazury, Wielkopolska, Kujawy), the highest level of fungal colonization was noted in the pea seeds harvested in Warmia and Mazury.

2012 ◽  
Vol 61 (2) ◽  
pp. 175-187
Author(s):  
Barbara Majchrzak ◽  
Bogdan Dubis ◽  
Adam Okorski

Field studies were carried out in the 2004 - 2005 growing seasons. The mycological analysis of malting barley (varieties Prestige and Sezam) grains was performed twice: on seeds stored for 30 days and on seeds stored for five months. The influence of fungicide treatment on species diversity and the amount of fungal pathogens on kernels of both varieties of malting barley were determined in the studies. Main fungal pathogens of both varieties of malting barley were field fungal species, such as: <i>Alternaria alternata</i>, <i>Epicocum purpurascens</i>, and fungi of the genus Fusarium. The extension of the grain storage period to five months resulted in an increased share of pathogenic species.


Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 884
Author(s):  
Maciej Żelechowski ◽  
Tomasz Molcan ◽  
Katarzyna Bilska ◽  
Kamil Myszczyński ◽  
Jacek Olszewski ◽  
...  

Soybean is an important, high protein source of food and feed. However, like other agricultural grains, soybean may pose a risk to human and animal health due to contamination of the grains with toxigenic Fusaria and associated mycotoxins. In this study, we investigated the diversity of Fusaria on a panel of 104 field isolates obtained from soybean grains during the growing seasons in 2017–2020. The results of species-specific PCR analyses showed that Fusarium avenaceum was the most common (n = 40) species associated with soybean grains in Poland, followed by F. equiseti (n = 22) and F. sporotrichioides (11 isolates). A set of isolates, which was not determined based on PCR analyses, was whole genome sequenced. Multiple sequence analyses using tef-1α, top1, rpb1, rpb2, tub2, pgk, cam and lsu genes showed that most of them belonged to Equiseti clade. Three cryptic species from this clade: F. clavum, F. flagelliforme and FIESC 31 (lacking Latin binomial) were found on soybean for the first time. This is the first report demonstrating the prevalence of Fusaria on soybean grains in Poland.


Author(s):  
Frank C. Odds

The pathogenesis of fungal disease involves an interplay between fungal virulence factors and host immune responses. Most fungal pathogens are opportunists that preferentially invade hosts with immune defects, but the fact that relative pathogenicity varies between fungal species (and even between different strains within a species) is evidence that fungi have evolved multiple, different molecular virulence factors. Experiments in which genes encoding putative virulence attributes are specifically disrupted and the resulting mutants are tested for virulence in a range of vertebrate and invertebrate hosts have identified or confirmed many gene products as significant for the pathogenesis of various types of fungal disease. These include factors determining fungal shape in vivo, biofilm formation, and a plethora of surface components, including adhesins and hydrolytic enzymes. This chapter provides an overview of fungal virulence attributes.


2009 ◽  
Vol 58 (9) ◽  
pp. 1182-1189 ◽  
Author(s):  
Alastair Muir ◽  
A. Toby A. Jenkins ◽  
Gordon Forrest ◽  
John Clarkson ◽  
Alan Wheals

This study describes the development of a novel assay to detect fungal DNA and identify the most clinically relevant invasive human pathogenic fungi to the species level using oligonucleotide probes, labelled with electrochemically active groups, and solid-state electrodes. A panfungal probe designed against the 18S rRNA gene region, capable of detecting all fungal pathogens tested, and species-specific probes, designed against the ITS2 region for detection of the five Candida species most commonly encountered in the clinical setting (Candida albicans, Candida glabrata, Candida parapsilosis species complex, Candida krusei and Candida tropicalis), are described. When tested with PCR-amplified DNA from both type and clinical strains of the relevant species, the probes were able to positively identify the relevant fungi, indicated by production of a current significantly elevated above the background reading. No cross-reactivity was observed with any of the species-specific probes when compared with nine non-target Candida species or in the presence of human DNA equivalent to an equal number of ITS2 targets. The panfungal probe gave results that were similarly positive against 15 other fungal species and also did not cross-react with human DNA. The limit of detection of the assay was shown to be approximately 1 genome equivalent for all probes using extracted genomic DNA.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jing Wang ◽  
Chaoyun Xu ◽  
Qiming Sun ◽  
Jinrong Xu ◽  
Yunrong Chai ◽  
...  

Abstract Background Microbiome interactions are important determinants for ecosystem functioning, stability, and health. In previous studies, it was often observed that bacteria suppress potentially pathogenic fungal species that are part of the same plant microbiota; however, the underlying microbe-microbe interplay remains mostly elusive. Here, we explored antagonistic interactions of the fungus Fusarium graminearum and bacterium Streptomyces hygroscopicus at the molecular level. Both are ubiquitous members of the healthy wheat microbiota; under dysbiosis, the fungus causes devastating diseases. Results In co-cultures, we found that Streptomyces alters the fungal acetylome leading to substantial induction of fungal autophagy. The bacterium secrets rapamycin to inactivate the target of rapamycin (TOR), which subsequently promotes the degradation of the fungal histone acetyltransferase Gcn5 through the 26S proteasome. Gcn5 negatively regulates fungal autophagy by acetylating the autophagy-related protein Atg8 at the lysine site K13 and blocking cellular relocalization of Atg8. Thus, degradation of Gcn5 triggered by rapamycin was found to reduce Atg8 acetylation, resulting in autophagy induction in F. graminearum. Conclusions Autophagy homeostasis plays an essential role in fungal growth and competition, as well as for virulence. Our work reveals a novel post-translational regulation of autophagy initiated by a bacterial antibiotic. Rapamycin was shown to be a powerful modulator of bacteria–fungi interactions with potential importance in explaining microbial homeostasis in healthy plant microbiomes. The autophagic process provides novel possibilities and targets to biologically control pathogens.


2021 ◽  
Vol 22 (2) ◽  
pp. 483
Author(s):  
Marija Ivanov ◽  
Abhilash Kannan ◽  
Dejan S. Stojković ◽  
Jasmina Glamočlija ◽  
Ricardo C. Calhelha ◽  
...  

Candidaalbicans represents one of the most common fungal pathogens. Due to its increasing incidence and the poor efficacy of available antifungals, finding novel antifungal molecules is of great importance. Camphor and eucalyptol are bioactive terpenoid plant constituents and their antifungal properties have been explored previously. In this study, we examined their ability to inhibit the growth of different Candida species in suspension and biofilm, to block hyphal transition along with their impact on genes encoding for efflux pumps (CDR1 and CDR2), ergosterol biosynthesis (ERG11), and cytotoxicity to primary liver cells. Camphor showed excellent antifungal activity with a minimal inhibitory concentration of 0.125–0.35 mg/mL while eucalyptol was active in the range of 2–23 mg/mL. The results showed camphor’s potential to reduce fungal virulence traits, that is, biofilm establishment and hyphae formation. On the other hand, camphor and eucalyptol treatments upregulated CDR1;CDR2 was positively regulated after eucalyptol application while camphor downregulated it. Neither had an impact on ERG11 expression. The beneficial antifungal activities of camphor were achieved with an amount that was non-toxic to porcine liver cells, making it a promising antifungal compound for future development. The antifungal concentration of eucalyptol caused cytotoxic effects and increased expression of efflux pump genes, which suggests that it is an unsuitable antifungal candidate.


Horticulturae ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 16
Author(s):  
Heba Hassan ◽  
Aishah Alatawi ◽  
Awatif Abdulmajeed ◽  
Manal Emam ◽  
Hemmat Khattab

Photosystem II is extremely susceptible to environmental alterations, particularly high temperatures. The maintenance of an efficient photosynthetic system under stress conditions is one of the main issues for plants to attain their required energy. Nowadays, searching for stress alleviators is the main goal for maintaining photosynthetic system productivity and, thereby, crop yield under global climate change. Potassium silicate (K2SiO3, 1.5 mM) and silicon dioxide nanoparticles (SiO2NPs, 1.66 mM) were used to mitigate the negative impacts of heat stress (45 °C, 5 h) on wheat (Triticum aestivum L.) cv. (Shandawelly) seedlings. The results showed that K2SiO3 and SiO2NPs diminished leaf rolling symptoms and electrolyte leakage (EL) of heat-stressed wheat leaves. Furthermore, the maximum quantum yield of photosystem II (Fv/Fm) and the performance index (PIabs), as well as the photosynthetic pigments and organic solutes including soluble sugars, sucrose, and proline accumulation, were increased in K2SiO3 and SiO2NPs stressed leaves. At the molecular level, RT-PCR analysis showed that K2SiO3 and SiO2NPs treatments stimulated the overexpression of PsbH, PsbB, and PsbD genes. Notably, this investigation indicated that K2SiO3 was more effective in improving wheat thermotolerance compared to SiO2NPs. The application of K2SiO3 and SiO2NPs may be one of the proposed approaches to improve crop growth and productivity to tolerate climatic change.


Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 901 ◽  
Author(s):  
Asiya Gusa ◽  
Sue Jinks-Robertson

Genome rearrangements and ploidy alterations are important for adaptive change in the pathogenic fungal species Candida and Cryptococcus, which propagate primarily through clonal, asexual reproduction. These changes can occur during mitotic growth and lead to enhanced virulence, drug resistance, and persistence in chronic infections. Examples of microevolution during the course of infection were described in both human infections and mouse models. Recent discoveries defining the role of sexual, parasexual, and unisexual cycles in the evolution of these pathogenic fungi further expanded our understanding of the diversity found in and between species. During mitotic growth, damage to DNA in the form of double-strand breaks (DSBs) is repaired, and genome integrity is restored by the homologous recombination and non-homologous end-joining pathways. In addition to faithful repair, these pathways can introduce minor sequence alterations at the break site or lead to more extensive genetic alterations that include loss of heterozygosity, inversions, duplications, deletions, and translocations. In particular, the prevalence of repetitive sequences in fungal genomes provides opportunities for structural rearrangements to be generated by non-allelic (ectopic) recombination. In this review, we describe DSB repair mechanisms and the types of resulting genome alterations that were documented in the model yeast Saccharomyces cerevisiae. The relevance of similar recombination events to stress- and drug-related adaptations and in generating species diversity are discussed for the human fungal pathogens Candida albicans and Cryptococcus neoformans.


1993 ◽  
Vol 23 (10) ◽  
pp. 2286-2299 ◽  
Author(s):  
R.A. Lautenschlager

Reviewed studies of the effects of forest herbicide applications on wildlife often lacked replication, pretreatment information, and (or) were conducted for only one or two growing seasons after treatment. Because of these problems, as well as the use of dissimilar sampling techniques, study conclusions have sometimes been contradictory. A review of eight studies of the effects of herbicide treatments on northern songbird populations in regenerating clearcuts indicates that total songbird populations are seldom reduced during the growing season after treatment. Densities of species that use early successional brushy, deciduous cover are sometimes reduced, while densities of species which commonly use more open areas, sometimes increase. A review of 14 studies of the effects of herbicide treatments on small mammals indicates that like songbirds, small mammal responses are species specific. Some species are unaffected, while some select and others avoid herbicide-treated areas. Only studies that use kill or removal trapping to study small mammal responses show density reductions associated with herbicide treatment. It seems that some small mammal species may be reluctant to venture into disturbed areas, although residents in those areas are apparently not affected by the disturbance. Fourteen relevant studies examined the effects of conifer release treatments on moose and deer foods and habitat use. Conifer release treatments reduce the availability of moose browse for as long as four growing seasons after treatment. The degree of reduction during the growing season after treatment varies with the herbicide and rate used. Deer use of treated areas remains unchanged or increases during the first growing season after treatment. Eight years after treating a naturally regenerated spruce–fir stand browse was three to seven times more abundant on treated than on control plots (depending on the chemical and rate used). Forage quality (nitrogen, ash, and moisture) of crop trees increased one growing season after the soil-active herbicide simazine was applied to control competition around outplanted 3-year-old balsam fir seedlings.


1997 ◽  
Vol 61 (1) ◽  
pp. 17-32
Author(s):  
G A Marzluf

In the fungi, nitrogen metabolism is controlled by a complex genetic regulatory circuit which ensures the preferential use of primary nitrogen sources and also confers the ability to use many different secondary nitrogen sources when appropriate. Most structural genes encoding nitrogen catabolic enzymes are subject to nitrogen catabolite repression, mediated by positive-acting transcription factors of the GATA family of proteins. However, certain GATA family members, such as the yeast DAL80 factor, act negatively to repress gene expression. Selective expression of the genes which encode enzymes for the metabolism of secondary nitrogen sources is often achieved by induction, mediated by pathway-specific factors, many of which have a GAL4-like C6/Zn2 DNA binding domain. Regulation within the nitrogen circuit also involves specific protein-protein interactions, as exemplified by the specific binding of the negative-acting NMR protein with the positive-acting NIT2 protein of Neurospora crassa. Nitrogen metabolic regulation appears to play a significant role in the pathogenicity of certain animal and plant fungal pathogens.


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