Fusaric acid, aFusarium verticillioidesmetabolite, antagonistic to the endophytic biocontrol bacteriumBacillus mojavensis

2004 ◽  
Vol 82 (7) ◽  
pp. 878-885 ◽  
Author(s):  
C W Bacon ◽  
D M Hinton ◽  
J K Porter ◽  
A E Glenn ◽  
G Kuldau
Keyword(s):  
Fusarium Moniliforme ◽  
Biocontrol Agent ◽  
Bacterial Colonization ◽  
Fusarium Verticillioides ◽  
Fusaric Acid ◽  
Endophytic Bacterium ◽  
Fungal Endophyte ◽  
Plant Diseases ◽  
Control Group ◽  
In Planta

An endophytic bacterium, Bacillus mojavensis Roberts, Nakamura & Cohan, was patented as a nonpathogenic biocontrol for plant diseases. However, before this bacterium can be used as a biocontrol agent, it must be evaluated against homologous competing organisms, some of which are equally successful endophytes, such as species of Fusarium that are symptomless endophytes, especially on maize. Preliminary field trials using this bacterium as a biocontrol agent against production of the fumonisin mycotoxins caused by infection of maize with Fusarium verticillioides (Sacc.) Nirenberg (= Fusarium moniliforme Sheldon) was less than that observed with greenhouse studies. Fusarium verticillioides and other species produce fusaric acid. Fusaric acid at concentrations as low as 22 µmol/L accounted for a 41% reduction in CFU compared with the control group, while concentrations of 223 µmol/L and higher resulted in total toxicity to the bacterium. Mutants of F. verticillioides that produced low concentrations of fusaric acid did not affect the endophytic CFU of the bacterium in seedlings. These results suggest that fusaric acid accounted for the reduction of bacterial colonization and the resulting poor biocontrol activity and suggested its importance to the fungus is as an antibiotic, which assists in the in planta competition for the intercellular niche colonized by F. verticillioides during its endotrophic state.Key words: Fusarium moniliforme, Fusarium verticillioides, bacterial endophyte, fungal endophyte, fumonisin.

scholarly journals Pepper Bacterial Spot Control by Bacillus velezensis: Bioprocess Solution

2020 ◽  
Vol 8 (10) ◽  
pp. 1463
Author(s):  
Ivana Pajčin ◽  
Vanja Vlajkov ◽  
Marcus Frohme ◽  
Sergii Grebinyk ◽  
Mila Grahovac ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
Plant Protection ◽  
Medium Composition ◽  
Plant Diseases ◽  
Mass Spectrometry Analysis ◽  
Economic Losses ◽  
In Planta ◽  
Bacterial Spot ◽  
Bacillus Velezensis ◽  
Food Isolate

Pepper bacterial spot is one of the most severe plant diseases in terms of infection persistence and economic losses when it comes to fresh pepper fruits used in nutrition and industrial processing. In this study, Bacillus velezensis IP22 isolated from fresh cheese was used as a biocontrol agent of pepper bacterial spot, whose main causal agent is the cosmopolitan pathogen Xanthomonas euvesicatoria. After optimization of the cultivation medium composition aimed at maximizing of the antimicrobial activity against X. euvesicatoria and validation of the optimized medium at the scale of a laboratory bioreactor, in planta tests were performed. The results have showed significant suppression of bacterial spot symptoms in pepper plants by the produced biocontrol agent, as well as reduction of disease spreading on the healthy (uninoculated) pepper leaves. Furthermore, HPLC-MS (high pressure liquid chromatography–mass spectrometry) analysis was employed to examine antimicrobial metabolites produced by B. velezensis IP22, where lipopeptides were found with similar m/z values compared to lipopeptides from fengycin and locillomycin families. The bioprocess solution developed at the laboratory scale investigated in this study represents a promising strategy for production of pepper bacterial spot biocontrol agent based on B. velezensis IP22, a food isolate with a great perspective for application in plant protection.

scholarly journals Fusarium verticillioides SGE1 Is Required for Full Virulence and Regulates Expression of Protein Effector and Secondary Metabolite Biosynthetic Genes

2014 ◽  
Vol 27 (8) ◽  
pp. 809-823 ◽  
Author(s):  
Daren W. Brown ◽  
Mark Busman ◽  
Robert H. Proctor
Keyword(s):  
Secondary Metabolism ◽  
Fusarium Verticillioides ◽  
Fusaric Acid ◽  
Orthologous Gene ◽  
Gene Clusters ◽  
Effector Proteins ◽  
Surface Proteins ◽  
Regulation Of Transcription ◽  
In Planta ◽  
Food And Feed

The transition from one lifestyle to another in some fungi is initiated by a single orthologous gene, SGE1, that regulates markedly different genes in different fungi. Despite these differences, many of the regulated genes encode effector proteins or proteins involved in the synthesis of secondary metabolites (SM), both of which can contribute to pathogenicity. Fusarium verticillioides is both an endophyte and a pathogen of maize and can grow as a saprophyte on dead plant material. During growth on live maize plants, the fungus can synthesize a number of toxic SM, including fumonisins, fusarins, and fusaric acid, that can contaminate kernels and kernel-based food and feed. In this study, the role of F. verticillioides SGE1 in pathogenicity and secondary metabolism was examined by gene deletion analysis and transcriptomics. SGE1 is not required for vegetative growth or conidiation but is required for wild-type pathogenicity and affects synthesis of multiple SM, including fumonisins and fusarins. Induced expression of SGE1 enhanced or reduced expression of hundreds of genes, including numerous putative effector genes that could contribute to growth in planta; genes encoding cell surface proteins; gene clusters required for synthesis of fusarins, bikaverin, and an unknown metabolite; as well as the gene encoding the fumonisin cluster transcriptional activator. Together, our results indicate that SGE1 has a role in global regulation of transcription in F. verticillioides that impacts but is not absolutely required for secondary metabolism and pathogenicity on maize.

In planta reduction of maize seedling stalk lesions by the bacterial endophyteBacillus mojavensis

2011 ◽  
Vol 57 (6) ◽  
pp. 485-492 ◽  
Author(s):  
Charles W. Bacon ◽  
Dorothy M. Hinton
Keyword(s):  
Fusarium Verticillioides ◽  
Fusaric Acid ◽  
Maize Seedling ◽  
Wild Type ◽  
In Planta ◽  
Lesion Development ◽  
Bacillus Mojavensis ◽  
Acid Tolerant ◽  
Bacteria And Fungi ◽  
Maize Kernels

Maize ( Zea mays L.) is susceptible to infection by Fusarium verticillioides through autoinfection and alloinfection, resulting in diseases and contamination of maize kernels with the fumonisin mycotoxins. Attempts at controlling this fungus are currently being done with biocontrol agents such as bacteria, and this includes bacterial endophytes, such as Bacillus mojavensis . In addition to producing fumonisins, which are phytotoxic and mycotoxic, F. verticillioides also produces fusaric acid, which acts both as a phytotoxin and as an antibiotic. The question now is Can B. mojavensis reduce lesion development in maize during the alloinfection process, simulated by internode injection of the fungus? Mutant strains of B. mojavensis that tolerate fusaric acid were used in a growth room study to determine the development of stalk lesions, indicative of maize seedling blight, by co-inoculations with a wild-type strain of F. verticillioides and with non-fusaric acid producing mutants of F. verticillioides. Lesions were measured on 14-day-old maize stalks consisting of treatment groups inoculated with and without mutants and wild-type strains of bacteria and fungi. The results indicate that the fusaric-acid-tolerant B. mojavensis mutant reduced stalk lesions, suggesting an in planta role for this substance as an antibiotic. Further, lesion development occurred in maize infected with F. verticillioides mutants that do not produce fusaric acid, indicating a role for other phytotoxins, such as the fumonisins. Thus, additional pathological components should be examined before strains of B. mojavensis can be identified as being effective as a biocontrol agent, particularly for the control of seedling disease of maize.

scholarly journals Mycotoxigenic Fusarium and Deoxynivalenol Production Repress Chitinase Gene Expression in the Biocontrol Agent Trichoderma atroviride P1

2003 ◽  
Vol 69 (6) ◽  
pp. 3077-3084 ◽  
Author(s):  
Matthias P. Lutz ◽  
Georg Feichtinger ◽  
Genevi�ve D�fago ◽  
Brion Duffy
Keyword(s):  
Gene Expression ◽  
Crop Residues ◽  
Biocontrol Agent ◽  
Fusaric Acid ◽  
Chitinase Gene ◽  
Plant Diseases ◽  
Trichoderma Atroviride ◽  
Wide Range ◽  
Biocontrol Activity ◽  
Inhibitor Of Protein Synthesis

ABSTRACT Mycotoxin contamination associated with head blight of wheat and other grains caused by Fusarium culmorum and F. graminearum is a chronic threat to crop, human, and animal health throughout the world. One of the most important toxins in terms of human exposure is deoxynivalenol (DON) (formerly called vomitoxin), an inhibitor of protein synthesis with a broad spectrum of toxigenicity against animals. Certain Fusarium toxins have additional antimicrobial activity, and the phytotoxin fusaric acid has recently been shown to modulate fungus-bacterium interactions that affect plant health (Duffy and D�fago, Phytopathology 87:1250-1257, 1997). The potential impact of DON on Fusarium competition with other microorganisms has not been described previously. Any competitive advantage conferred by DON would complicate efforts to control Fusarium during its saprophytic growth on crop residues that are left after harvest and constitute the primary inoculum reservoir for outbreaks in subsequent plantings. We examined the effect of the DON mycotoxin on ecological interactions between pathogenic Fusarium and Trichoderma atroviride strain P1, a competitor fungus with biocontrol activity against a wide range of plant diseases. Expression of the Trichoderma chitinase genes, ech42 and nag1, which contribute to biocontrol activity, was monitored in vitro and on crop residues of two maize cultivars by using goxA reporter gene fusions. We found that DON-producing F. culmorum and F. graminearum strains repressed expression of nag1-gox. DON-negative wild-type Fusarium strains and a DON-negative mutant with an insertional disruption in the tricothecene biosynthetic gene, tri5, had no effect on antagonist gene expression. The role of DON as the principal repressor above other pathogen factors was confirmed. Exposure of Trichoderma to synthetic DON or to a non-DON-producing Fusarium mutant resulted in the same level of nag1-gox repression as the level observed with DON-producing Fusarium. DON repression was specific for nag1-gox and had no effect, either positive or negative, on expression of another key chitinase gene, ech42. This is the first demonstration that a target pathogen down-regulates genes in a fungal biocontrol agent, and our results provide evidence that mycotoxins have a novel ecological function as factors in Fusarium competitiveness.

scholarly journals ITRAQ-based quantitative proteomic analysis of Fusarium moniliforme (Fusarium verticillioides) in response to Phloridzin inducers

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Rong Zhang ◽  
Weitao Jiang ◽  
Xin Liu ◽  
Yanan Duan ◽  
Li Xiang ◽  
...  
Keyword(s):  
Fusarium Moniliforme ◽  
Abiotic Factors ◽  
Fusarium Verticillioides ◽  
Protein Profile ◽  
Sugar Metabolism ◽  
Differentially Expressed ◽  
Pcr Analysis ◽  
Differentially Expressed Proteins ◽  
Apple Replant Disease ◽  
Qrt Pcr

Abstract Background Apple replant disease (ARD) has been reported from all major fruit-growing regions of the world, and is often caused by biotic factors (pathogen fungi) and abiotic factors (phenolic compounds). In order to clarify the proteomic differences of Fusarium moniliforme under the action of phloridzin, and to explore the potential mechanism of F. moniliforme as the pathogen of ARD, the role of Fusarium spp. in ARD was further clarified. Methods In this paper, the quantitative proteomics method iTRAQ analysis technology was used to analyze the proteomic differences of F. moniliforme before and after phloridzin treatment. The differentially expressed protein was validated by qRT-PCR analysis. Results A total of 4535 proteins were detected, and 293 proteins were found with more than 1.2 times (P< 0.05) differences. In-depth data analysis revealed that 59 proteins were found with more than 1.5 times (P< 0.05) differences, and most proteins were consistent with the result of qRT-PCR. Differentially expressed proteins were influenced a variety of cellular processes, particularly metabolic processes. Among these metabolic pathways, a total of 8 significantly enriched KEGG pathways were identified with at least 2 affiliated proteins with different abundance in conidia and mycelium. Functional pathway analysis indicated that up-regulated proteins were mainly distributed in amino sugar, nucleotide sugar metabolism, glycolysis/ gluconeogenesis and phagosome pathways. Conclusions This study is the first to perform quantitative proteomic investigation by iTRAQ labeling and LC-MS/MS to identify differentially expressed proteins in F. moniliforme under phloridzin conditions. The results confirmed that F. moniliforme presented a unique protein profile that indicated the adaptive mechanisms of this species to phloridzin environments. The results deepened our understanding of the proteome in F. moniliforme in response to phloridzin inducers and provide a basis for further exploration for improving the efficiency of the fungi as biocontrol agents to control ARD.

scholarly journals Vancomycin-Resistant Enterococci and Extended-Spectrum β-Lactamase-Producing Bacterial Colonization of the Cervix after Emergency Cerclage: Is It Safe?

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 933
Author(s):  
Won-Kyu Jang ◽  
Jin-Gon Bae
Keyword(s):  
Early Onset ◽  
Neonatal Death ◽  
Medical Center ◽  
Bacterial Colonization ◽  
Control Group ◽  
Vancomycin Resistant Enterococci ◽  
Extended Spectrum ◽  
Early Onset Sepsis ◽  
Cervical Surgery ◽  
Vancomycin Resistant

Antimicrobial resistance is currently becoming a global threat to human health. We performed a retrospective study on patients who underwent emergency cerclage between January 2016 and December 2018 at the Dongsan Medical Center. Cervical culture was first performed before surgery to confirm that there was no infection and was repeated on days 1, 4, and 7 after surgery. A total of 85 pregnant women underwent emergency cerclage. Among them, six patients had vancomycin-resistant enterococci (VRE) colonization in the cervix after cerclage, and 23 patients developed extended-spectrum β-lactamase (ESBL)-producing bacterial colonization in the cervix. The average gestational age at delivery was lower in the VRE group. Neonatal death was also significantly higher in the VRE group. The rate of occurrence of early-onset sepsis was also higher in the VRE group, and both VRE and ESBL-producing bacterial colonization cases in which early-onset sepsis occurred resulted in neonatal death. The prognosis of cervical VRE colonization after cervical surgery was poor, whereas the prognosis of ESBL-producing bacterial colonization in the cervix did not differ significantly from that of the control group. However, careful neonatal treatment is required considering that early-onset sepsis is fatal to the newborn.

scholarly journals 1548. Association of bacterial colonization in ulcerative lesions of the diabetic foot together with the cicatrization process

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S773-S775
Author(s):  
Alexander A Ozoria Loveras ◽  
Jacques Paré Espinal ◽  
David de luna ◽  
Noemi Acevedo
Keyword(s):  
Diabetic Foot ◽  
Bacterial Colonization ◽  
Healing Process ◽  
Foot Ulcer ◽  
Primary Source ◽  
Diabetic Foot Ulcer ◽  
Care Program ◽  
Antimicrobial Treatment ◽  
Control Group ◽  
Experimental Group

Abstract Background In 2018, a review of the scientific literature identifed biofilm studies in the past 3 years. Wherein, the role of the biofilm in the progression of the diabetic foot ulcer with the presence of biofilm is reviewed. As a result, tissue sampling is more effective than transcure, Levin, and aspiration. A study in Cuba evaluate the effectiveness of a new proposal for antimicrobial treatment in patients with diabetic foot infection in 2017. The method used was a experimental type of two groups. The control group, was treated with the treatment scheme proposed in the Comprehensive Care Program for the patient with diabetic foot ulcer (PAIPUPD). Instead, the other experimental group was treated according to the scheme based on the local microbial map. They used a random distribution. Using the Wagner classification, there were patients classificate with a grade of W2 (13% of patients), W3 (66%) and W4 (12%). The most frequent germs found were Staphylococcus aureus, Escherichia coli and Enterobacter sp. The experimental group required less days with hospitalization. Methods This is an observational study of primary source with a non-probability sample with 58 patients. Adult patients diagnosed with type 2 diabetes mellitus, with diabetic foot, Wagner classification 1, 2 and 3, who attended the healing area of the Institute of Diabetes of Santiago were included. After identifying the colonized pathogen, its cicatrization process was evaluate for four weeks. Results Of the total sample, 12.07% belonged to Wagner 1, 43.1% to Wagner 2 and 44.83% to the Wagner 3 classification. In the case of the Wagner 3 group, S. aureus and Pseudomona aeruginosa were present in 6 cases. Despite the infectious processes detected by the culture, the patients showed a successful cicatrization process after four weeks of evaluation. Graph 1: Isolated Microorganism Vs Wagner’s Degree (n=60) Graph 2: Gram positive microorganism vs. healing process per week in patients with diabetic foot (n=22) Graph 3: Gram-negative microorganism vs. healing process (n=33) Conclusion During the four weeks of clinical evaluation, more than 88% of patients progressed positively to clinical recovery, regardless of the type of bacteria colonized and/or their resistance to antibiotics. Disclosures All Authors: No reported disclosures

scholarly journals The Effect of Fusarium verticillioides Fumonisins on Fatty Acids, Sphingolipids, and Oxylipins in Maize Germlings

2021 ◽  
Vol 22 (5) ◽  
pp. 2435
Author(s):  
Marzia Beccaccioli ◽  
Manuel Salustri ◽  
Valeria Scala ◽  
Matteo Ludovici ◽  
Andrea Cacciotti ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fusarium Verticillioides ◽  
Fungal Growth ◽  
Defense Responses ◽  
Ceramide Synthase ◽  
Ear Rot ◽  
In Planta ◽  
Disease Symptoms ◽  
The Impact

Fusarium verticillioides causes multiple diseases of Zea mays (maize) including ear and seedling rots, contaminates seeds and seed products worldwide with toxic chemicals called fumonisins. The role of fumonisins in disease is unclear because, although they are not required for ear rot, they are required for seedling diseases. Disease symptoms may be due to the ability of fumonisins to inhibit ceramide synthase activity, the expected cause of lipids (fatty acids, oxylipins, and sphingolipids) alteration in infected plants. In this study, we explored the impact of fumonisins on fatty acid, oxylipin, and sphingolipid levels in planta and how these changes affect F. verticillioides growth in maize. The identity and levels of principal fatty acids, oxylipins, and over 50 sphingolipids were evaluated by chromatography followed by mass spectrometry in maize infected with an F. verticillioides fumonisin-producing wild-type strain and a fumonisin-deficient mutant, after different periods of growth. Plant hormones associated with defense responses, i.e., salicylic and jasmonic acid, were also evaluated. We suggest that fumonisins produced by F. verticillioides alter maize lipid metabolism, which help switch fungal growth from a relatively harmless endophyte to a destructive necrotroph.

scholarly journals Influence of Flower Thrips on Fusarium Hardlock Severity

Plant Disease ◽  
2007 ◽  
Vol 91 (11) ◽  
pp. 1423-1429 ◽  
Author(s):  
D. J. Mailhot ◽  
J. J. Marois ◽  
D. L. Wright
Keyword(s):  
Gossypium Hirsutum ◽  
Untreated Control ◽  
Yield Loss ◽  
Fusarium Verticillioides ◽  
Field Conditions ◽  
Control Group ◽  
Flower Thrips ◽  
The Impact ◽  
Field Plots

Cotton (Gossypium hirsutum) fiber is sometimes affected by hardlock, which is characterized by a failure of the fiber to expand outward from the boll at maturity. Because affected fiber is inaccessible to mechanical harvesters, yield loss can be considerable. Hardlock has been linked to infection by Fusarium verticillioides. The involvement of flower thrips (Frankliniella spp.), which are commonly found in cotton flowers, was explored. At 1100 h, approximately 10% of cotton flowers contained thrips that were carrying F. verticillioides. The effect of thrips and/or Fusarium in flowers and bolls was explored under greenhouse conditions. Exposing flowers to Fusarium and thrips resulted in bolls with the most severe symptoms. Exposure to either Fusarium or thrips alone resulted in more hardlock than was noted in the control group. The impact of thrips was also evaluated under field conditions. Field plots were treated with insecticides, a fungicide, both, or left untreated. Insecticides reduced thrips numbers and reduced hardlock severity. The fungicide had no impact on thrips numbers and was less effective at reducing hardlock. Combining insecticide and fungicide applications was no more effective than using insecticides alone, although it more frequently increased yield. The untreated control plots generally had the most severe hardlock and lowest yields. Reducing hardlock severity resulted in higher yields, although not consistently. These studies suggest that thrips increase the severity of hardlock, and reducing their numbers may diminish hardlock severity.

Sign in / Sign up

Export Citation Format

Share Document