scholarly journals Novel Genetic Dysregulations and Oxidative Damage in Fusarium graminearum Induced by Plant Defense Eliciting Psychrophilic Bacillus atrophaeus TS1

2021 ◽  
Vol 22 (22) ◽  
pp. 12094
Author(s):  
Muhammad Zubair ◽  
Ayaz Farzand ◽  
Faiza Mumtaz ◽  
Abdur Rashid Khan ◽  
Taha Majid Mahmood Sheikh ◽  
...  
Keyword(s):  
Low Temperature ◽  
Plant Defense ◽  
Fusarium Graminearum ◽  
Extracellular Enzymes ◽  
Cellular Damage ◽  
Economic Losses ◽  
Bacillus Atrophaeus ◽  
Potential Biocontrol Agent ◽  
Bacterial Treatment ◽  
Fungal Genes

This study elaborates inter-kingdom signaling mechanisms, presenting a sustainable and eco-friendly approach to combat biotic as well as abiotic stress in wheat. Fusarium graminearum is a devastating pathogen causing head and seedling blight in wheat, leading to huge yield and economic losses. Psychrophilic Bacillus atrophaeus strain TS1 was found as a potential biocontrol agent for suppression of F. graminearum under low temperature by carrying out extensive biochemical and molecular studies in comparison with a temperate biocontrol model strain Bacillus amyloliquefaciens FZB42 at 15 and 25 °C. TS1 was able to produce hydrolytic extracellular enzymes as well as antimicrobial lipopeptides, i.e., surfactin, bacillomycin, and fengycin, efficiently at low temperatures. The Bacillus strain-induced oxidative cellular damage, ultrastructural deformities, and novel genetic dysregulations in the fungal pathogen as the bacterial treatment at low temperature were able to downregulate the expression of newly predicted novel fungal genes potentially belonging to necrosis inducing protein families (fgHCE and fgNPP1). The wheat pot experiments conducted at 15 and 25 °C revealed the potential of TS1 to elicit sudden induction of plant defense, namely, H2O2 and callose enhanced activity of plant defense-related enzymes and induced over-expression of defense-related genes which accumulatively lead to the suppression of F. graminearum and decreased diseased leaf area.

scholarly journals Alternaria spp. IN FOODS: MYCOTOXINS, CELLULAR DAMAGE AND POSSIBLE HEALTH RISK

2018 ◽  
Vol 15 (30) ◽  
pp. 19-26
Author(s):  
F. P. de ANDRADE JUNIOR ◽  
T. W. B. ALVES ◽  
M. H. P. de LIRA ◽  
M. E. da S. MENEZES ◽  
I. O. LIMA
Keyword(s):  
Fruits And Vegetables ◽  
Cell Damage ◽  
Food Contamination ◽  
Great Majority ◽  
Fungal Species ◽  
Cellular Damage ◽  
Food Storage ◽  
Economic Losses ◽  
Teratogenic Action ◽  
Species Being

The genus Alternaria is composed of filamentous, dematiaceous, saprophytic and pathogenic fungal species, being responsible for great economic losses during the harvest and food storage. The present study aimed to do a bibliographical survey about the main foods contaminated by Alternaria spp. as well as discuss possible health risks arising from cell damage caused by mycotoxins. It is a literature narrative type review, carried out using Medline/Pubmed, Lilacs, Scielo and Science Direct databases, utilizing documents published between years 2000 and 2017 approaching food contamination by Alternaria spp. A wide diversity of foods contaminated by species of the genus Alternaria was found in literature, with a greater emphasis on cereals, fruits and vegetables. This possible contamination may favor the development of mycotoxins that in their great majority present genotoxic, mutagenic, carcinogenic, cytotoxic and teratogenic action. However, due to a large variety of contaminated foods, that is a necessity to adapt Brazilian legislation regarding parameters that impose limits on the amount of mycotoxins produced by Alternaria spp. since the national legislation does not encompass limits for all types of toxins that this genus is capable of producing.

Exposure to low temperature prepares the turtle brain to withstand anoxic environments during overwintering

2021 ◽  
Author(s):  
Ebrahim Lari ◽  
Leslie T. Buck
Keyword(s):  
Membrane Potential ◽  
Low Temperature ◽  
Action Potential ◽  
Pyramidal Neurons ◽  
Cellular Damage ◽  
Severe Hypoxia ◽  
Painted Turtle ◽  
Whole Cell ◽  
Voltage Gated ◽  
The Impact

In most vertebrates, anoxia drastically reduces the production of the essential adenosine triphosphate (ATP) to power its many necessary functions, and consequently, cell death occurs within minutes. However, some vertebrates, such as the painted turtle (Chrysemys picta bellii), have evolved the ability to survive months without oxygen by simultaneously decreasing ATP supply and demand, surviving the anoxic period without any apparent cellular damage. The impact of anoxia on the metabolic function of painted turtles has received a lot of attention. Still, the impact of low temperature has received less attention and the interactive effect of anoxia and temperature even less. In the present study, we investigated the interactive impacts of reduced temperature and severe hypoxia on the electrophysiological properties of pyramidal neurons in painted turtle cerebral cortex. Our results show that an acute reduction in temperature from 20 to 5°C decreases membrane potential, action potential width and amplitude, and whole-cell conductance. Importantly, acute exposure to 5°C considerably slows membrane repolarization by voltage-gated K+ channels. Exposing pyramidal cells to severe hypoxia in addition to an acute temperature change slightly depolarized membrane potential but did not alter action potential amplitude or width and whole-cell conductance. These results suggest that acclimation to low temperatures, preceding severe environmental hypoxia, induces cellular responses in pyramidal neurons that facilitate survival under low oxygen concentration. In particular, our results show that temperature acclimation invokes a change in voltage-gated K+ channel kinetics that overcomes the acute inhibition of the channel.

scholarly journals Effects of Putrescine Application on Peach Fruit during Storage

2019 ◽  
Vol 11 (7) ◽  
pp. 2013 ◽  
Author(s):  
Nadeem Abbasi ◽  
Irfan Ali ◽  
Ishfaq Hafiz ◽  
Mekhled Alenazi ◽  
Muhammad Shafiq
Keyword(s):  
Low Temperature ◽  
Quality Characteristics ◽  
Fruit Growth ◽  
Economic Losses ◽  
Spray Application ◽  
Peach Fruit ◽  
Colour Perception ◽  
Low Temperature Storage ◽  
Positive Effects ◽  
Temperature Storage

The peach industry faces serious economic losses because of the short “green” life of the fruit at postharvest. In the present study, we investigated the effects of putrescine (PUT) application on the quality characteristics, pattern of ripening, storage behaviour and shelf life of peach fruit during low-temperature storage. The aqueous solution of PUT (0, 1, 2 and 3 mM) was applied to the peach trees at three distinctive stages of fruit growth and development. The fruits, harvested at the commercial stage of maturity, were stored at 1 ± 1 °C and 90 ± 2% relative humidity for 6 weeks. The data for fruit firmness, total soluble solids (SSC), titratable acidity (TA), ascorbic acid (AsA) content, rate of ethylene production, chilling injury (CI) index and colour perception were collected at harvest and then on a weekly basis throughout the storage period. The results showed that spray application of PUT significantly reduced the incidence of CI and reduced the rates of fruit softening, loss in fruit weight, SSC, TA, AsA content and fading of skin colour during storage, regardless of the doses of PUT applied, or the time of application. However, the positive effects on the quality characteristics of peach fruit, including CI, were more pronounced with the higher doses of PUT, specifically when applied at 2 mM. In conclusion, CI in peach fruit may be substantially alleviated by the spray application of 1–3 mM PUT during fruit growth without compromising the quality of the fruit for up to 6 weeks in low-temperature storage.

Incidence of Deoxynivalenol in Wheat Flour in Argentina and GC–ECD Method Validation

2019 ◽  
Vol 102 (6) ◽  
pp. 1721-1724 ◽  
Author(s):  
Mercedes Cirio ◽  
Marcela Villarreal ◽  
Tomás M López Seal ◽  
Mariano E Simón ◽  
Camila S Santana Smersu ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Wheat Flour ◽  
Fusarium Graminearum ◽  
Health Risks ◽  
Human Population ◽  
Economic Losses ◽  
Head Blight ◽  
Tolerance Limits ◽  
Intermediate Precision ◽  
Median Level

Abstract Background: Deoxynivalenol (DON) is a mycotoxin produced mainly by Fusarium graminearum. This fungus is the main plant pathogen associated with Fusarium Head Blight (FHB) wheat disease, causing significant economic losses and exposing human population to severe health risks. DON production changes widely among different years and areas and its effects are larger in years with abundant rainfall and high relative humidity. To date, Argentina has not established DON tolerance limits. Objective: To validate a method using GC with electron capture detector (GC-ECD) and to provide evidence of DON contamination in Argentinean commercial wheat flour. Results: A total of 34 different flour samples were analyzed obtaining 91.2% of incidence with a mean level of 243 µg/kg and a median level of 165 µg/kg. The method showed acceptable LOD (24 µg/kg) and LOQ (79 µg/kg), relative SD (RSD) of the intermediate precision (RSD = 5.98%), recovery (89.3%) and uncertainty (14%). Conclusions: The method was successfully validated according to the studied parameters. Incidence results for DON contamination are low and in accordance with previous studies for years with low FHB incidence in wheat.

scholarly journals Biological Control of Thielaviopsis paradoxa and Colletotrichum gloeosporioides by the Extracellular Enzymes of Wickerhamomyces anomalus

Agriculture ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 325
Author(s):  
Luis Fernando Zepeda-Giraud ◽  
Dario Rafael Olicón-Hernández ◽  
Juan Pablo Pardo ◽  
Minerva Georgina Araiza Villanueva ◽  
Guadalupe Guerra-Sánchez
Keyword(s):  
Extracellular Enzymes ◽  
Colletotrichum Gloeosporioides ◽  
Culture Media ◽  
Crop Protection ◽  
Fungal Growth ◽  
Antagonistic Effect ◽  
Economic Losses ◽  
Post Harvest ◽  
Wickerhamomyces Anomalus ◽  
Yeast Peptone Dextrose

An alternative to chemical fungicides in post-harvest diseases are the use of biocontrol agents and their extracellular products against phytopathogens. Two relevant agents in post-harvest infections are Thielaviopsis paradoxa and Colletotrichum gloeosporioides, causing large economic losses in cacao, pineapple, and avocado during storage. In this work, we evaluated the effect of Wickerhamomyces anomalus, an effective biocontrol agent, against these filamentous fungi, focusing on the production of extracellular enzymes and their effect on fungal growth and germination. Moreover, we evaluated the use of inactivated fungal biomass as an inducer in complete (Potato Dextrose Agar and Yeast Peptone Dextrose) and minimal culture media. The antagonistic effect of W anomalus on the growth of both phytopathogens was also studied. The extracellular enzymes in YPD cultures, using T. paradoxa inactivated biomass as the best inducer, were capable of inhibiting the germination of both phytopathogens. In minimal media, only the production of a 30 kDa glucanase with activity against laminarin was observed. The enzyme was effective against the spore germination of T. paradoxa. In post-harvest crop protection tests, growth inhibition of T. paradoxa was observed using the cell-free enzyme extract, which is a promising system to protect cocoa fruits from T. paradoxa during post-harvest.

scholarly journals The Dynamin-Like GTPase FgSey1 Plays a Critical Role in Fungal Development and Virulence in Fusarium graminearum

2020 ◽  
Vol 86 (11) ◽  
Author(s):  
Xuefa Chong ◽  
Chenyu Wang ◽  
Yao Wang ◽  
Yixiao Wang ◽  
Liyuan Zhang ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Vegetative Growth ◽  
Animal Feed ◽  
Pathogenic Fungus ◽  
Critical Role ◽  
Effective Control ◽  
Economic Losses ◽  
Head Blight ◽  
Fungal Development ◽  
Content Type

ABSTRACT Fusarium graminearum, the main pathogenic fungus causing Fusarium head blight (FHB), produces deoxynivalenol (DON), a key virulence factor, which is synthesized in the endoplasmic reticulum (ER). Sey1/atlastin, a dynamin-like GTPase protein, is known to be required for homotypic fusion of ER membranes, but the functions of this protein are unknown in pathogenic fungi. Here, we characterized Sey1/atlastin homologue FgSey1 in F. graminearum. Like Sey1/atlastin, FgSey1 is located in the ER. The FgSEY1 deletion mutant exhibited significantly reduced vegetative growth, asexual development, DON biosynthesis, and virulence. Moreover, the ΔFgsey1 mutant was impaired in the formation of normal lipid droplets (LDs) and toxisomes, both of which participate in DON biosynthesis. The GTPase, helix bundle (HB), transmembrane segment (TM), and cytosolic tail (CT) domains of FgSey1 are essential for its function, but only the TM domain is responsible for its localization. Furthermore, the mutants FgSey1K63A and FgSey1T87A lacked GTPase activity and failed to rescue the defects of the ΔFgsey1 mutant. Collectively, our data suggest that the dynamin-like GTPase protein FgSey1 affects the generation of LDs and toxisomes and is required for DON biosynthesis and pathogenesis in F. graminearum. IMPORTANCE Fusarium graminearum is a major plant pathogen that causes Fusarium head blight (FHB) of wheats worldwide. In addition to reducing the plant yield, F. graminearum infection of wheats also results in the production of deoxynivalenol (DON) mycotoxins, which are harmful to humans and animals and therefore cause great economic losses through pollution of food products and animal feed. At present, effective strategies for controlling FHB are not available. Therefore, understanding the regulation mechanisms of fungal development, pathogenesis, and DON biosynthesis is important for the development of effective control strategies of this disease. In this study, we demonstrated that a dynamin-like GTPase protein Sey1/atlastin homologue, FgSey1, is required for vegetative growth, DON production, and pathogenicity in F. graminearum. Our results provide novel information on critical roles of FgSey1 in fungal pathogenicity; therefore, FgSey1 could be a potential target for effective control of the disease caused by F. graminearum.

scholarly journals Genomic Identification of the TOR Signaling Pathway as a Target of the Plant Alkaloid Antofine in the Phytopathogen Fusarium graminearum

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Christopher Mogg ◽  
Christopher Bonner ◽  
Li Wang ◽  
Johann Schernthaner ◽  
Myron Smith ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Fusarium Graminearum ◽  
Mode Of Action ◽  
Biological Activities ◽  
Extensive Study ◽  
Economic Losses ◽  
Head Blight ◽  
Tor Signaling ◽  
Content Type ◽  
Chemical Genomic

ABSTRACT Antofine, a phenanthroindolizidine alkaloid, is a bioactive natural product isolated from milkweeds that exhibits numerous biological activities, including anticancer, antimicrobial, antiviral, and anti-inflammatory properties. However, the direct targets and mode of action of antofine have not been determined. In this report, we show that antofine displays antifungal properties against the phytopathogen Fusarium graminearum, the cause of Fusarium head blight disease (FHB). FHB does devastating damage to agriculture, causing billions of dollars in economic losses annually. We therefore sought to understand the mode of action of antofine in F. graminearum using insights from yeast chemical genomic screens. We used haploinsufficiency profiling (HIP) to identify putative targets of antofine in yeast and identified three candidate targets, two of which had homologs in F. graminearum. The Fusarium homologues of two targets, glutamate dehydrogenase (FgGDH) and resistance to rapamycin deletion 2 (FgRRD2), can bind antofine. Of the two genes, only the Fgrrd2 knockout displayed a loss of virulence in wheat, indicating that RRD2 is an antivirulence target of antofine in F. graminearum. Mechanistically, we demonstrate that antofine disrupts the interaction between FgRRD2 and FgTap42, which is part of the Tap42-phosphatase complex in the target of rapamycin (TOR) signaling pathway, a central regulator of cell growth in eukaryotes and a pathway of extensive study for controlling numerous pathologies. IMPORTANCE Fusarium head blight caused by the fungal pathogen Fusarium graminearum is a devastating disease of cereal crops worldwide, with limited effective chemical treatments available. Here we show that the natural alkaloid compound antofine can inhibit fusarium head blight in wheat. Using yeast genomic screening, we identified the TOR pathway component RRD2 as a target of antofine that is also required for F. graminearum pathogenicity.

scholarly journals Novel Genes of Fusarium graminearum That Negatively Regulate Deoxynivalenol Production and Virulence

2009 ◽  
Vol 22 (12) ◽  
pp. 1588-1600 ◽  
Author(s):  
Donald M. Gardiner ◽  
Kemal Kazan ◽  
John M. Manners
Keyword(s):  
Gene Expression ◽  
Fusarium Graminearum ◽  
Global Analysis ◽  
Gene Clusters ◽  
Head Blight ◽  
Knock Out ◽  
Serious Disease ◽  
Amine Compounds ◽  
Fungal Genes ◽  
Fungal Gene Expression

Fusarium head blight of wheat, caused by Fusarium graminearum, is a serious disease resulting in both reduced yields and contamination of grain with trichothecene toxins, with severe consequences for mammalian health. Recently, we have identified several related amine compounds such as agmatine and putrescine that promote the production of high levels of trichothecene toxins, such as deoxynivalenol (DON), in culture by F. graminearum and F. sporotrichioides. Here, a global analysis of fungal gene expression using the Affymetrix Fusarium GeneChip during culture under DON-inducing conditions compared with noninducing conditions is reported. Agmatine differentially regulated a large number of fungal genes, including both known and previously uncharacterized putative secondary metabolite biosynthetic gene clusters. In silico prediction of binding sites for the transcriptional regulator (TRI6) controlling TRI gene expression and gene expression analysis in a TRI6 mutant of F. graminearum showed that three of the differentially regulated genes were under the control of TRI6. Gene knock-out mutations of two of these genes resulted in mutants with massively increased production of DON and increased aggressiveness toward wheat. Our results not only identify a novel mechanism of negative regulation of DON production and virulence in F. graminearum but also point out the potential of this pathogen to evolve with an ability to produce massively increased amounts of toxins and increased virulence.

scholarly journals RGB Imaging as Tool to Analyze the Growth of Fusarium graminearum in Infected Oats (Avena sativa) and Rice (Oryza sativa)

2019 ◽  
Author(s):  
Edgar Cambaza ◽  
Shigenobu Koseki ◽  
Shuso Kawamura
Keyword(s):  
Fusarium Graminearum ◽  
Color Change ◽  
Growth Models ◽  
Economic Losses ◽  
Selection Strategy ◽  
Imaging Analysis ◽  
Current Growth ◽  
Imagej Software ◽  
Pearson Correlations ◽  
Mycelial Phase

Fusarium graminearum is a cereal pathogen responsible for economic losses worldwide every year. An understanding of its growth is key to control its infection, but current growth models are limited because their size-based approach provides little information about the mold's metabolism. Recently, a RGB (red, green and blue) imaging analysis demonstrated the predictability of F. graminearum color change as it grows in yeast extract agar (YEA). This study aimed to verify the same phenomenon in oats (aw = 0.94, 0.97 and 0.99) and rice (aw = 0.97, 0.98 and 0.99). Photos were taken using a professional camera and a smartphone (iPhone 6) after incubation and during the subsequent 16 days, and average RGB was quantified using ImageJ software. The photos showed very similar color variations, regardless of the type of grain or aw. The mold first adopted a k-selection strategy by growing as a mycelium and then a r-selection strategy, increasing spore production. All RGB channels showed positive Pearson correlations between them (p < 0.001) and it was possible to design a model showing two lag phases, the first prior to a mycelial phase and the second prior to a sporular phase at the end of the experiment.

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