scholarly journals Chitin Deacetylase, a Novel Target for the Design of Agricultural Fungicides

2021 ◽  
Vol 7 (12) ◽  
pp. 1009
Author(s):  
Jesús M. Martínez-Cruz ◽  
Álvaro Polonio ◽  
Riccardo Zanni ◽  
Diego Romero ◽  
Jorge Gálvez ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Fungal Pathogens ◽  
Plant Immunity ◽  
Fungal Growth ◽  
Grey Mould ◽  
Docking Studies ◽  
Phytopathogenic Fungi ◽  
Disease Suppression ◽  
Chitin Deacetylase ◽  
Starting Point

Fungicide resistance is a serious problem for agriculture. This is particularly apparent in the case of powdery mildew fungi. Therefore, there is an urgent need to develop new agrochemicals. Chitin is a well-known elicitor of plant immunity, and fungal pathogens have evolved strategies to overcome its detection. Among these strategies, chitin deacetylase (CDA) is responsible for modifying immunogenic chitooligomers and hydrolysing the acetamido group in the N-acetylglucosamine units to avoid recognition. In this work, we tested the hypothesis that CDA can be an appropriate target for antifungals using the cucurbit powdery mildew pathogen Podosphaera xanthii. According to our hypothesis, RNAi silencing of PxCDA resulted in a dramatic reduction in fungal growth that was linked to a rapid elicitation of chitin-triggered immunity. Similar results were obtained with treatments with carboxylic acids such as EDTA, a well-known CDA inhibitor. The disease-suppression activity of EDTA was not associated with its chelating activity since other chelating agents did not suppress disease. The binding of EDTA to CDA was confirmed by molecular docking studies. Furthermore, EDTA also suppressed green and grey mould-causing pathogens applied to oranges and strawberries, respectively. Our results conclusively show that CDA is a promising target for control of phytopathogenic fungi and that EDTA could be a starting point for fungicide design.

scholarly journals First Report of Powdery Mildew of Parsley Caused by Erysiphe heraclei in Florida

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 461-461 ◽  
Author(s):  
R. Raid ◽  
C. Miller ◽  
K. Pernezny
Keyword(s):  
Powdery Mildew ◽  
Fungal Pathogens ◽  
Fungal Growth ◽  
Leaf Tissue ◽  
Signs And Symptoms ◽  
Climatic Conditions ◽  
Petroselinum Crispum ◽  
First Report ◽  
Dark Green ◽  
Vegetable Farm

Parsley (Petroselinum crispum (Mill.) Nym. ex A.W. Hill) is an important leaf crop in the Everglades Agricultural Area of southern Florida. During the spring of 2005 and 2006, disease signs and symptoms resembling those incited by powdery mildew were observed on parsley at a commercial vegetable farm located 15 km east of Belle Glade. Symptoms consisted of leaf chlorosis, particularly in the dense lower canopy, and desiccation of affected tissue. A dense, white-to-light gray fungal growth was visible macroscopically on the surface of affected leaf tissue. Microscopic examinations revealed ectophytic hyphae with lobed appressoria and hyaline, straight conidiophores bearing single conidia. Conidia were short-cylindrical to cylindrical, measured 33 to 44 μm long and 13 to 16 μm wide, and lacked fibrosin bodies. Conidiophore foot cells were also cylindrical, straight, and measured 27 to 37 × 9 to 10 μm. Ascocarps of the teleomorph were not observed. The fungus closely matched the description of Erysiphe heraclei DC, a pathogen previously reported as attacking parsley on the U.S. West Coast (1,2). Pathogenicity was verified by inoculating adaxial leaf surfaces of 12 plants (cv. Dark Green Italian) with conidia collected from infected tissue by using a small brush. Inoculated plants and 12 noninoculated plants were lightly misted, held in a moist chamber for 48 h (22°C), and then incubated in a growth chamber for 4 weeks at 22°C with a photoperiod of 16 h. Symptoms that developed on inoculated plants were similar to those observed in the field, with no symptoms evident on the controls treated in a similar manner. To our knowledge, this is the first report of powdery mildew on parsley in Florida, even though parsley has been grown in the area for at least six decades. Noted as being somewhat unique among fungal pathogens because it favors dry rather than moist climatic conditions, it is probably no coincidence that powdery mildew was observed both years during the month of April, the height of Florida's dry season. The fact that monthly rainfall totals of 22 and 35 mm were recorded during April of 2004 and 2005, respectfully, well below the historical average of 72 mm, may have been a contributing influence. Glawe et al. (1), in issuing a first report of E. heraclei on carrots and parsley in the state of Washington and observing ascocarps on carrot tissue, mentioned the prospect of contaminated seed serving as a potential source of dissemination. Although they did not observe the teleomorph on parsley, prospects for its occurrence seem likely. With the bulk of parsley seed planted in Florida being produced in Washington, Oregon, or California, the observations reported herein may provide credence to such a hypothesis. References: (1) D. A. Glawe et al. Online publication. doi:10.1094/PHP-2005-0114-01-HN. Plant Health Progress, 2005. (2) S. T. Koike and G. S. Saenz. Plant Dis. 78:1219, 1994.

scholarly journals Nucleosome patterns in four plant pathogenic fungi with contrasted genome structures

2021 ◽  
Author(s):  
Colin Clairet ◽  
Nicolas LAPALU ◽  
Adeline Simon ◽  
Jessica L. Soyer ◽  
Muriel Viaud ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fungal Pathogens ◽  
Genome Structure ◽  
Axenic Culture ◽  
Fungal Growth ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Rna Seq ◽  
Cellular Mechanisms ◽  
Environment Control

Fungal pathogens represent a serious threat towards agriculture, health, and environment. Control of fungal diseases on crops necessitates a global understanding of fungal pathogenicity determinants and their expression during infection. Genomes of phytopathogenic fungi are often compartmentalized: the core genome contains housekeeping genes whereas the fast-evolving genome mainly contains transposable elements and species-specific genes. In this study, we analysed nucleosome landscapes of four phytopathogenic fungi with contrasted lifestyles and genome organisations to describe and compare nucleosome repartition patterns in relation with genome structure and gene expression level. We combined MNase-seq and RNA-seq analyses to concomitantly map nucleosome-rich and transcriptionally active regions during fungal growth in axenic culture; we developed the tool MSTS to analyse and visualise data obtained from MNase-seq experiments in combination with other genomic data and notably RNA-seq expression data. We observed different characteristics of nucleosome profiles between species, as well as between genomic regions within the same species. We further linked nucleosome repartition and gene expression. Our findings support that nucleosome positioning and occupancies are subjected to evolution, in relation with underlying genome sequence modifications. Understanding genomic organisation and its role in expression regulation is the next gear to understand complex cellular mechanisms and their evolution.

scholarly journals A Protein from the Mold Aspergillus giganteus Is a Potent Inhibitor of Fungal Plant Pathogens

2001 ◽  
Vol 14 (11) ◽  
pp. 1327-1331 ◽  
Author(s):  
L. Vila ◽  
V. Lacadena ◽  
P. Fontanet ◽  
A. Martinez del Pozo ◽  
B. San Segundo
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Magnaporthe Grisea ◽  
Crop Protection ◽  
Fungal Growth ◽  
Phytopathogenic Fungi ◽  
Antifungal Protein ◽  
Aspergillus Giganteus ◽  
Fungal Plant Pathogens ◽  
Total Inhibition

A purified preparation of antifungal protein (AFP) from Aspergillus giganteus exhibited potent antifungal activity against the phytopathogenic fungi Magnaporthe grisea and Fusarium moniliforme, as well as the oomycete pathogen Phytophthora infestans. Under conditions of total inhibition of fungal growth, no toxicity of AFP toward rice protoplasts was observed. Additionally, application of AFP on rice plants completely inhibited M. grisea growth. These results are discussed in relation to the potential of the afp gene to enhance crop protection against fungal pathogens in transgenic plants.

Inhibition of Fungal Growth by Macerated Plant Tissues in a Closed Environment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 476e-476
Author(s):  
Craig S. Charron ◽  
Catherine O. Chardonnet ◽  
Carl E. Sams
Keyword(s):  
Radial Growth ◽  
Fungal Pathogens ◽  
Solid Phase ◽  
Indian Mustard ◽  
Fungal Growth ◽  
Allyl Isothiocyanate ◽  
Pythium Ultimum ◽  
Alternative Methods ◽  
Gas Chromatography Mass Spectrometry ◽  
Clean Air

The U.S. Clean Air Act bans the use of methyl bromide after 2001. Consequently, the development of alternative methods for control of soilborne pathogens is imperative. One alternative is to exploit the pesticidal properties of macerated tissues of Brassica spp. This study tested the potential of several Brassica spp. for control of fungal pathogens. Pythium ultimum Trow or Rhizoctonia solani Kühn plugs on potato-dextrose agar on petri dishes were sealed in 500-ml glass jars (at 22 °C) containing macerated leaves (10 g) from one of six Brassica spp. Radial growth was measured 24, 48, and 72 h after inoculation. Indian mustard (B. juncea) was the most suppressive, followed by `Florida Broadleaf' mustard (B. juncea). Volatile compounds in the jars were sampled with a solid-phase microextraction device (SPME) and identified by gas chromatography-mass spectrometry (GC-MS). Allyl isothiocyanate (AITC) comprised over 90% of the total volatiles measured from Indian mustard and `Florida Broadleaf' mustard. Isothiocyanates were detected in jars with all plants except broccoli. (Z)-3-hexenyl acetate was emitted by all plants and was the predominant volatile of `Premium Crop' broccoli (B. oleracea L. var. italica), `Michihili Jade Pagoda' Chinese cabbage (B. pekinensis), `Charmant' cabbage (B. oleracea L. var. capitata), and `Blue Scotch Curled' kale (B. oleracea L. var. viridis). To assess the influence of AITC on radial growth of P. ultimum and R. solani, AITC was added to jars to give headspace concentrations of 0.10, 0.20, and 0.30 mg·L–1 (mass of AITC per volume of headspace). Growth of both fungi was inhibited by 0.10 mg·L–1 AITC. 0.20 mg·L–1 AITC was fungicidal to P. ultimum although the highest AITC level tested (0.30 mg·L–1) did not terminate R. solani growth. These results indicate that residues from some Brassica spp. may be a viable part of a soilborne pest control strategy.

scholarly journals Post-translational regulation of autophagy is involved in intra-microbiome suppression of fungal pathogens

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jing Wang ◽  
Chaoyun Xu ◽  
Qiming Sun ◽  
Jinrong Xu ◽  
Yunrong Chai ◽  
...  
Keyword(s):  
Translational Regulation ◽  
Fungal Pathogens ◽  
Fungal Growth ◽  
Fungal Species ◽  
26S Proteasome ◽  
Healthy Plant ◽  
Autophagy Induction ◽  
Histone Acetyltransferase Gcn5 ◽  
Plant Microbiota ◽  
Autophagic Process

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.

scholarly journals Disruption of barley immunity to powdery mildew by an in-frame Lys-Leu deletion in the essential protein SGT1

Genetics ◽  
2020 ◽  
Vol 217 (2) ◽  
Author(s):  
Antony V E Chapman ◽  
Matthew Hunt ◽  
Priyanka Surana ◽  
Valeria Velásquez-Zapata ◽  
Weihui Xu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Fungal Pathogens ◽  
Novel Mutation ◽  
Exome Capture ◽  
Resistance Locus ◽  
Hordeum Vulgare L ◽  
Powdery Mildew Fungus ◽  
Pathogen Effectors ◽  
Cell Processes ◽  
Disease Resistances

Abstract Barley (Hordeum vulgare L.) Mla (Mildew resistance locus a) and its nucleotide-binding, leucine-rich-repeat receptor (NLR) orthologs protect many cereal crops from diseases caused by fungal pathogens. However, large segments of the Mla pathway and its mechanisms remain unknown. To further characterize the molecular interactions required for NLR-based immunity, we used fast-neutron mutagenesis to screen for plants compromised in MLA-mediated response to the powdery mildew fungus, Blumeria graminis f. sp. hordei. One variant, m11526, contained a novel mutation, designated rar3 (required for Mla6 resistance3), that abolishes race-specific resistance conditioned by the Mla6, Mla7, and Mla12 alleles, but does not compromise immunity mediated by Mla1, Mla9, Mla10, and Mla13. This is analogous to, but unique from, the differential requirement of Mla alleles for the co-chaperone Rar1 (required for Mla12 resistance1). We used bulked-segregant-exome capture and fine mapping to delineate the causal mutation to an in-frame Lys-Leu deletion within the SGS domain of SGT1 (Suppressor of G-two allele of Skp1, Sgt1ΔKL308–309), the structural region that interacts with MLA proteins. In nature, mutations to Sgt1 usually cause lethal phenotypes, but here we pinpoint a unique modification that delineates its requirement for some disease resistances, while unaffecting others as well as normal cell processes. Moreover, the data indicate that the requirement of SGT1 for resistance signaling by NLRs can be delimited to single sites on the protein. Further study could distinguish the regions by which pathogen effectors and host proteins interact with SGT1, facilitating precise editing of effector incompatible variants.

scholarly journals Biodirected Synthesis of Silver Nanoparticles Using Aqueous Honey Solutions and Evaluation of Their Antifungal Activity against Pathogenic Candida Spp.

2021 ◽  
Vol 22 (14) ◽  
pp. 7715
Author(s):  
Grzegorz Czernel ◽  
Dominika Bloch ◽  
Arkadiusz Matwijczuk ◽  
Jolanta Cieśla ◽  
Monika Kędzierska-Matysek ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antifungal Activity ◽  
Fungal Pathogens ◽  
Fungal Growth ◽  
Disc Diffusion ◽  
Candida Spp ◽  
Antifungal Effect ◽  
Synthesis Of Nanoparticles ◽  
Honey Solution ◽  
Diffusion Assay

Silver nanoparticles (AgNPs) were synthesized using aqueous honey solutions with a concentration of 2%, 10%, and 20%—AgNPs-H2, AgNPs-H10, and AgNPs-H20. The reaction was conducted at 35 °C and 70 °C. Additionally, nanoparticles obtained with the citrate method (AgNPs-C), while amphotericin B (AmB) and fluconazole were used as controls. The presence and physicochemical properties of AgNPs was affirmed by analyzing the sample with ultraviolet–visible (UV–Vis) and fluorescence spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS). The 20% honey solution caused an inhibition of the synthesis of nanoparticles at 35 °C. The antifungal activity of the AgNPs was evaluated using opportunistic human fungal pathogens Candida albicans and Candida parapsilosis. The antifungal effect was determined by the minimum inhibitory concentration (MIC) and disc diffusion assay. The highest activity in the MIC tests was observed in the AgNPs-H2 variant. AgNPs-H10 and AgNPs-H20 showed no activity or even stimulated fungal growth. The results of the Kirby–Bauer disc diffusion susceptibility test for C. parapsilosis strains indicated stronger antifungal activity of AgNPs-H than fluconazole. The study demonstrated that the antifungal activity of AgNPs is closely related to the concentration of honey used for the synthesis thereof.

scholarly journals Biological control of strawberry crown rot, root rot and grey mould by the beneficial fungus Aureobasidium pullulans

BioControl ◽  
2021 ◽  
Author(s):  
Mudassir Iqbal ◽  
Maha Jamshaid ◽  
Muhammad Awais Zahid ◽  
Erik Andreasson ◽  
Ramesh R. Vetukuri ◽  
...  
Keyword(s):  
Root Rot ◽  
Fungal Pathogens ◽  
Aureobasidium Pullulans ◽  
Grey Mould ◽  
Lesion Size ◽  
Plant Diseases ◽  
Crown Rot ◽  
Whole Plants

AbstractUtilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33–48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.

scholarly journals 4-Phenethyl-1-Propargylpiperidine-Derived Dual Inhibitors of Butyrylcholinesterase and Monoamine Oxidase B

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4118
Author(s):  
Tjaša Mazej ◽  
Damijan Knez ◽  
Anže Meden ◽  
Stanislav Gobec ◽  
Matej Sova
Keyword(s):  
Monoamine Oxidase ◽  
Docking Studies ◽  
Monoamine Oxidase B ◽  
Mao B ◽  
Initial Expectation ◽  
Excellent Starting Point ◽  
Starting Point ◽  
Dependent Inhibition ◽  
Dual Inhibitors ◽  
Time Dependent Inhibition

The multi-target-directed ligands (MTDLs) strategy is encouraged for the development of novel modulators targeting multiple pathways in the neurodegenerative cascade typical for Alzheimer’s disease (AD). Based on the structure of an in-house irreversible monoamine oxidase B (MAO-B) inhibitor, we aimed to introduce a carbamate moiety on the aromatic ring to impart cholinesterase (ChE) inhibition, and to furnish multifunctional ligands targeting two enzymes that are intricately involved in AD pathobiology. In this study, we synthesized three dual hMAO-B/hBChE inhibitors 13–15, with compound 15 exhibiting balanced, low micromolar inhibition of hMAO-B (IC50 of 4.3 µM) and hBChE (IC50 of 8.5 µM). The docking studies and time-dependent inhibition of hBChE confirmed the initial expectation that the introduced carbamate moiety is responsible for covalent inhibition. Therefore, dual-acting compound 15 represents an excellent starting point for further optimization of balanced MTDLs.

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.

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