scholarly journals Cell-cell recognition of host surfaces by pathogens. The adsorption of maize (Zea mays) root mucilage by surfaces of pathogenic fungi

1986 ◽  
Vol 233 (2) ◽  
pp. 395-405 ◽  
Author(s):  
J Gould ◽  
D H Northcote
Keyword(s):  
Zea Mays ◽  
Pathogenic Fungi ◽  
Fungal Species ◽  
Ionic Interactions ◽  
Cell Recognition ◽  
Vascular Wilt ◽  
Adsorption Capacities ◽  
Bivalent Cations ◽  
Root Mucilage ◽  
Fungal Adhesins

The adsorption of radioactive mucilage by pathogenic fungi was shown to be dependent upon time, the composition of mucilage, the type of fungal surface (conidia, hyphae, hyphal apices), fungal species, pH and bivalent cations. All fungal adhesins were inactivated by either proteinase or polysaccharase treatments. Adsorption was not inhibited by the numberous mono-, di- and oligo-saccharides that were tested individually, but it was inhibited absolutely by several polysaccharides. This suggested that adsorption of mucilage by pathogens involved conformational and ionic interactions between plant and fungal polymers but not fungal lectins bound to sugar residues of mucilage. Several fractionation schemes showed that pathogens bound only the most acidic of the variety of polymers that comprise mucilage. There was not any absolute distinction between ability to bind radioactive mucilage and type of pathogen or non-pathogen. However, there were notable differences in characteristics of adsorption between two types of pathogen. Differences were revealed by comparison of the adsorption capacities of conidia and germinant conidia and chromatography of radioactive mucilage on germinant conidia. An ectotrophic root-infecting fungus (a highly specialized pathogen) bound a greater proportion of mucilage than did a vascular-wilt fungus (of catholic host and tissue range) with more than one class of site for adsorption. In contrast with the vascular-wilt fungus, sites for adsorption on the specialized pathogen were present solely on surfaces formed by germination.

scholarly journals The Role of Fungi in the Cocoa Production Chain and the Challenge of Climate Change

2021 ◽  
Vol 7 (3) ◽  
pp. 202
Author(s):  
Johannes Delgado-Ospina ◽  
Junior Bernardo Molina-Hernández ◽  
Clemencia Chaves-López ◽  
Gianfranco Romanazzi ◽  
Antonello Paparella
Keyword(s):  
Climate Change ◽  
Fungal Infections ◽  
Close Association ◽  
Pathogenic Fungi ◽  
Fungal Species ◽  
Mitigation Strategies ◽  
Plant Diseases ◽  
Production Chain ◽  
Cocoa Production

Background: The role of fungi in cocoa crops is mainly associated with plant diseases and contamination of harvest with unwanted metabolites such as mycotoxins that can reach the final consumer. However, in recent years there has been interest in discovering other existing interactions in the environment that may be beneficial, such as antagonism, commensalism, and the production of specific enzymes, among others. Scope and approach: This review summarizes the different fungi species involved in cocoa production and the cocoa supply chain. In particular, it examines the presence of fungal species during cultivation, harvest, fermentation, drying, and storage, emphasizing the factors that possibly influence their prevalence in the different stages of production and the health risks associated with the production of mycotoxins in the light of recent literature. Key findings and conclusion: Fungi associated with the cocoa production chain have many different roles. They have evolved in a varied range of ecosystems in close association with plants and various habitats, affecting nearly all the cocoa chain steps. Reports of the isolation of 60 genera of fungi were found, of which only 19 were involved in several stages. Although endophytic fungi can help control some diseases caused by pathogenic fungi, climate change, with increased rain and temperatures, together with intensified exchanges, can favour most of these fungal infections, and the presence of highly aggressive new fungal genotypes increasing the concern of mycotoxin production. For this reason, mitigation strategies need to be determined to prevent the spread of disease-causing fungi and preserve beneficial ones.

scholarly journals Mitotic Recombination and Adaptive Genomic Changes in Human Pathogenic Fungi

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 901 ◽  
Author(s):  
Asiya Gusa ◽  
Sue Jinks-Robertson
Keyword(s):  
Fungal Pathogens ◽  
Repetitive Sequences ◽  
Pathogenic Fungi ◽  
Genetic Alterations ◽  
Fungal Species ◽  
Chronic Infections ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genomic Changes ◽  
Break Site ◽  
Repair Mechanisms

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.

scholarly journals Double Gamers—Can Modified Natural Regulators of Higher Plants Act as Antagonists against Phytopathogens? The Case of Jasmonic Acid Derivatives

2020 ◽  
Vol 21 (22) ◽  
pp. 8681
Author(s):  
Nicolò Orsoni ◽  
Francesca Degola ◽  
Luca Nerva ◽  
Franco Bisceglie ◽  
Giorgio Spadola ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Fungal Growth ◽  
Pathogenic Fungi ◽  
Inhibitory Effect ◽  
Fungal Species ◽  
Phytopathogenic Fungi ◽  
Phaeomoniella Chlamydospora ◽  
Horticultural Crops

As key players in biotic stress response of plants, jasmonic acid (JA) and its derivatives cover a specific and prominent role in pathogens-mediated signaling and hence are promising candidates for a sustainable management of phytopathogenic fungi. Recently, JA directed antimicrobial effects on plant pathogens has been suggested, supporting the theory of oxylipins as double gamers in plant-pathogen interaction. Based on these premises, six derivatives (dihydrojasmone and cis-jasmone, two thiosemicarbazonic derivatives and their corresponding complexes with copper) have been evaluated against 13 fungal species affecting various economically important herbaceous and woody crops, such as cereals, grapes and horticultural crops: Phaeoacremonium minimum, Neofusicoccum parvum, Phaeomoniella chlamydospora, Fomitiporia mediterranea, Fusarium poae, F. culmorum, F. graminearum, F. oxysporum f. sp. lactucae,F. sporotrichioides, Aspergillus flavus, Rhizoctonia solani,Sclerotinia spp. and Verticillium dahliae. The biological activity of these compounds was assessed in terms of growth inhibition and, for the two mycotoxigenic species A. flavus and F. sporotrichioides, also in terms of toxin containment. As expected, the inhibitory effect of molecules greatly varied amongst both genera and species; cis-jasmone thiosemicarbazone in particular has shown the wider range of effectiveness. However, our results show that thiosemicarbazones derivatives are more effective than the parent ketones in limiting fungal growth and mycotoxins production, supporting possible applications for the control of pathogenic fungi.

scholarly journals New Bis-Alkenoic Acid Derivatives from a Marine-Derived Fungus Fusarium solani H915

Marine Drugs ◽  
2018 ◽  
Vol 16 (12) ◽  
pp. 483 ◽  
Author(s):  
Shun-Zhi Liu ◽  
Xia Yan ◽  
Xi-Xiang Tang ◽  
Jin-Guo Lin ◽  
Ying-Kun Qiu
Keyword(s):  
Fusarium Solani ◽  
Zebrafish Embryo ◽  
Pathogenic Fungi ◽  
Fungal Species ◽  
Ionization Mass ◽  
Alkenoic Acid ◽  
Low Concentrations ◽  
Significant Toxicity ◽  
New Compounds ◽  
Acid Esters

Fusarium solani H915 is a fungus derived from mangrove sediments. From its ethyl acetate extract, a new alkenoic acid, fusaridioic acid A (1), three new bis-alkenoic acid esters, namely, fusariumester A1 (2), A2 (3) and B (4), together with three known compounds (5–7), were isolated. The structures of the new compounds were comprehensively characterized by high resolution electrospray ionization-mass spectrometry (HR-ESI-MS), 1D and 2D nuclear magnetic resonance (NMR). Additionally, the antifungal activities against tea pathogenic fungi Pestalotiopsis theae and Colletotrichum gloeosporioides were studied. The new compound, 4, containing a β-lactone ring, exhibited moderate inhibitory activity against P. theae, with an MIC of 50 μg/disc. Hymeglusin (6), a typical β-lactone antibiotic and a terpenoid alkaloid, equisetin (7), exhibited potent inhibitory activities against both fungal species. The isolated compounds were evaluated for their effects on zebrafish embryo development. Equisetin clearly imparted toxic effect on zebrafish even at low concentrations. However, none of the alkenoic acid derivatives exhibited significant toxicity to zebrafish eggs, embryos, or larvae. Thus, the β-lactone containing alkenoic acid derivatives from F. solani H915 are low in toxicity and are potent antifungal agents against tea pathogenic fungi.

scholarly journals Zeamatin-Like Protein (ZLP) Gene is Associated with Resistance against A. niger in Maize (Zea mays L.)

2016 ◽  
Vol 49 (2) ◽  
pp. 29-39
Author(s):  
A.M. Sajjad ◽  
T. Bahsir ◽  
S. Saeed ◽  
M. Iqbal ◽  
S. Islam ◽  
...  
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Hyphal Growth ◽  
Antimicrobial Activities ◽  
Fungal Species ◽  
High Rate ◽  
Sds Page ◽  
Pathogenesis Related ◽  
Enhanced Expression ◽  
Related Proteins

Abstract Maize (Zea mays L.) constitutes one of the most important crops worldwide with multi-billion dollar annual revenue. The plant is however a good substrate for growth, development and activity of filamentous fungi. A large number of fungal species causes spoilage and accumulation of mycotoxins. Plants restrict the hyphal growth by producing pathogenesis related proteins. So far 17 groups of such proteins are identified. PR-5 group comprises of the thaumatin-like proteins (TLPs), which have diverse modes of actions and act at various stages of fungal attack. Zeamatin-like protein (ZLP) is a member of TLPs, which is basically localized in seeds with enhanced expression during physiological growth and cellular differentiation. However a basal quantity is found in the leaves of many crop plants. Here we report the response of maize plant tissues against A. niger inoculation by measuring the variation in expression profile of a zeamatin-like gene. Conventional PCR coupled with RT-qPCR identifies a significant change in the expression magnitude of ZLP in pre- and post-inoculated plant samples. SDS-PAGE, followed by antimicrobial activities against A. niger, E.coli, P. aeruginosa, B. cereus, S. aureus and S. typhimurium, however, do not register a direct relationship with enhancement in gene expression. It is in line with the fact that response to pathogenesis in plants is a multigenic activity involving a series of responsible/induced genes. The assay developed is useful in primary sorting out of the maize hybrids with respect to their resistance against Aspergillus spp., especially in areas with high rate of incidence of fungal pathogenesis.

Virulence and in vitro Characteristics of Pathogenic Fungi Isolated from Soil by Baiting with Coptotermes formosanus (Isoptera: Rhinotermitidae)

2003 ◽  
Vol 38 (3) ◽  
pp. 342-358 ◽  
Author(s):  
Jianzhong Sun ◽  
James R. Fuxa ◽  
Gregg Henderson
Keyword(s):  
Pathogenic Fungi ◽  
Fungal Species ◽  
Coptotermes Formosanus ◽  
Survival Times ◽  
Fungal Virulence ◽  
Fungal Isolates ◽  
Sampling Locations ◽  
Lethal Doses

Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) was used as “bait” to isolate pathogenic fungi from soil. Ninety soil samples were collected from woodlands and pastures in the vicinities of Baton Rouge, New Orleans, and Lake Charles, LA, from which six Metarhizium anisopliae (Metsch.) Sorokin and nine Beauveria bassiana (Balsamo) Vuillemin isolates were obtained. Numbers of fungal isolates from the three sampling locations did not differ, but more isolates were found in woodlands than in pastures. Median lethal doses (LD50s) of these fungal species to C. formosanus were interspersed, indicating that fungal isolates rather than species had the greatest effect on virulence. Among nine Louisiana and two USDA isolates of B. bassiana, LD50s ranged from 4.95 × 103 to 4.96 × 105 conidia/termite, a difference of 100×. LD50s of six Louisiana and four USDA isolates of M. anisopliae ranged from 7.89 × 103 to 1.22 × 105 conidia/termite. Survival time also was used to compare virulence; M. anisopliae infections caused significantly shorter host survival times than B. bassiana. In vitro growth characteristics were significantly correlated with virulence against termites, suggesting that the characteristics of a fungus growing on agar might contribute to estimating the fungal virulence in vivo.

scholarly journals Risk of Fungal Infection to Dental Patients

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Jaqueline Lopes Damasceno ◽  
Rafael Aparecido dos Santos ◽  
Amir Horiquini Barbosa ◽  
Luciana Assirati Casemiro ◽  
Regina Helena Pires ◽  
...  
Keyword(s):  
Dental Treatment ◽  
Pathogenic Fungi ◽  
Fungal Species ◽  
Immunocompromised Patients ◽  
Dental Procedure ◽  
Average Amount ◽  
Dental Patients ◽  
Dental Clinics ◽  
Dental Equipment ◽  
The University

Fungi can cause various diseases, and some pathogenic fungi have been detected in the water of dental equipment. This environment offers suitable conditions for fungal biofilms to emerge, which can facilitate mycological contamination. This study verified whether the water employed in the dental units of two dental clinics at the University of Franca was contaminated with fungi. This study also evaluated the ability of the detected fungi to form biofilms. The high-revving engine contained the largest average amount of fungi, 14.93 ± 18.18 CFU/mL. The main fungal species verified in this equipment belonged to the generaAspergillusspp.,Fusariumspp.,Candidaspp., andRhodotorulaspp. Among the isolated filamentous fungi, only one fungus of the genusFusariumspp. did not form biofilms. As for yeasts, all theCandidaspp. isolates grew as biofilm, but none of theRhodotorulaspp. isolates demonstrated this ability. Given that professionals and patients are often exposed to water and aerosols generated by the dental procedure, the several fungal species detected herein represent a potential risk especially to immunocompromised patients undergoing dental treatment. Therefore, frequent microbiological monitoring of the water employed in dental equipment is crucial to reduce the presence of contaminants.

scholarly journals Efficacy of Organic Amendments and Soil Solarization against Wilt Severity and their Effects on Pathogenic Fungi and Tomato Production

2020 ◽  
Vol 9 (2) ◽  
pp. 93-103
Author(s):  
Hayfa Jabnoun-Khiareddine ◽  
Boutheina Mejdoub-Trabelsi ◽  
Rania Aydi Ben Abdallah ◽  
Riad Sedki Riad El-Mohamedy ◽  
Mejda Daami-Remadi
Keyword(s):  
Soil Amendments ◽  
Organic Amendments ◽  
Pathogenic Fungi ◽  
Cattle Manure ◽  
Soil Solarization ◽  
Infested Soil ◽  
Vascular Wilt ◽  
Tomato Production ◽  
Potato Dextrose Agar Medium ◽  
Tomato Plants

Soil solarization coupled or not with three soil amendments (cattle manure, bio-compost, and Biocat-15) was evaluated for its efficacy against vascular wilt severity on tomato plants grown under greenhouse conditions in a naturally infested soil. In solarized plots, wilt severity, estimated through the vascular discoloration extent and noted on randomly selected tomato plants, was significantly reduced following all the tested organic amendments. Complete wilt suppression was achieved using cattle manure. Vascular wilt severity noted on symptomatic tomato plants was 28% higher in non-solarized plots than in solarized ones and this for all organic amendments combined. Plots amended with Biocat-15 showed 29% less disease severity as compared to the two other treatments. Fungal isolations performed on Potato Dextrose Agar medium from roots, collars and stems of symptomatic and randomly selected plants, revealed the involvement of Fusarium oxysporum, F. solani, Rhizoctonia solani, Colletotrichum coccodes and R. bataticola in the observed wilts. Their isolation frequencies varied depending on wilt severity, solarization treatments (solarized or non-solarized) and tested soil amendments. Tomato production varied significantly depending on solarization treatments and tested organic amendments. Plants amended with cattle manure yielded significantly comparable production in the solarized and non-solarized plots while this production parameter was reduced by 19 and 27% following Biocompost and Biocat-15 treatments, respectively, on tomato plants grown in non-solarized plots. As for solarization effects, for all organic amendments combined, tomato production was significantly reduced by about 15% in the non-solarized greenhouse compared to the solarized one. Results from the current study showed that, under natural Tunisian conditions, single application of solarization combined with organic amendment not only reduced wilt severity, but also significantly enhanced tomato production. Thus, the repetitive combination of solarization and organic amendments could be a credible alternative for managing various soilborne fungal diseases and improving tomato yield in heavily infested fields.

scholarly journals Remote homology clustering identifies lowly conserved families of effector proteins in plant-pathogenic fungi

2021 ◽  
Vol 7 (9) ◽  
Author(s):  
Darcy A. B. Jones ◽  
Paula M. Moolhuijzen ◽  
James K. Hane
Keyword(s):  
Fungal Pathogens ◽  
Pathogenic Fungi ◽  
Comparison Method ◽  
Fungal Species ◽  
Effector Proteins ◽  
Plant Diseases ◽  
Plant Host ◽  
Homology Inference ◽  
Developing Area ◽  
Inference Methods

Plant diseases caused by fungal pathogens are typically initiated by molecular interactions between ‘effector’ molecules released by a pathogen and receptor molecules on or within the plant host cell. In many cases these effector-receptor interactions directly determine host resistance or susceptibility. The search for fungal effector proteins is a developing area in fungal-plant pathology, with more than 165 distinct confirmed fungal effector proteins in the public domain. For a small number of these, novel effectors can be rapidly discovered across multiple fungal species through the identification of known effector homologues. However, many have no detectable homology by standard sequence-based search methods. This study employs a novel comparison method (RemEff) that is capable of identifying protein families with greater sensitivity than traditional homology-inference methods, leveraging a growing pool of confirmed fungal effector data to enable the prediction of novel fungal effector candidates by protein family association. Resources relating to the RemEff method and data used in this study are available from https://figshare.com/projects/Effector_protein_remote_homology/87965.

scholarly journals Plant Pathogenic Fungi Associated with Coraebus florentinus (Coleoptera: Buprestidae) Attacks in Declining Oak Forests

Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 488 ◽  
Author(s):  
Claudia Pinna ◽  
Benedetto T. Linaldeddu ◽  
Vitale Deiana ◽  
Lucia Maddau ◽  
Lucio Montecchio ◽  
...  
Keyword(s):  
Sequence Data ◽  
Management Strategies ◽  
Pathogenic Fungi ◽  
Fungal Species ◽  
Western Mediterranean ◽  
Plant Pathogenic Fungi ◽  
Limited Information ◽  
Natural Ecosystems ◽  
Oak Trees ◽  
Coraebus Florentinus

The black-banded oak borer, Coraebus florentinus, is an emerging pest of oak trees in the western Mediterranean region. Larvae of the insect are xylophagous and progressively excavate an annular gallery that interrupts sap flow, resulting in the death of the attacked branches. Until now, limited information has been available regarding the ecological interactions between C. florentinus and the main plant pathogenic fungi involved in the etiology of oak decline. Knowledge of these interactions is important in understanding their impact in natural ecosystems and developing appropriate management strategies. Therefore, in this study, we characterized the fungal communities occurring in the exoskeleton of adults and larvae of C. florentinus and associated with the necrotic wood tissues surrounding the branch galleries of declining oak trees. A total of 29 fungal species were identified based on DNA sequence data and morphological features, of which 14 were from symptomatic woody tissues, six from insect exoskeleton, and nine from both insects and symptomatic wood tissues. The most frequent fungal species, Cryphonectria naterciae (15.9% of isolates), Dothiorella iberica (11.3%), and Diplodia corticola (9.9%), were isolated from both insect and gallery systems. All three species are well-known oak pathogens and are reported here, for the first time, to be associated with C. florentinus. At the same time, 89.6% of the fungal taxa were isolated from one or two sites, highlighting the site-dependence of fungal community assemblages.

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