scholarly journals Synergistic Phytotoxic Effects of Culmorin and Trichothecene Mycotoxins

Toxins ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 555 ◽  
Author(s):  
Wipfler ◽  
McCormick ◽  
Proctor ◽  
Teresi ◽  
Hao ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Root Elongation ◽  
Fusarium Species ◽  
Genomic Analysis ◽  
Wheat Root ◽  
Cereal Crops ◽  
Biosynthetic Gene ◽  
Head Blight ◽  
Biosynthetic Genes ◽  
Phytotoxic Effects

Species of the fungus Fusarium cause Fusarium head blight (FHB) of cereal crops and contaminate grain with sesquiterpenoid mycotoxins, including culmorin (CUL) and trichothecenes. While the phytotoxicity of trichothecenes, such as deoxynivalenol (DON), and their role in virulence are well characterized, less is known about the phytotoxicity of CUL and its role in the development of FHB. Herein, we evaluated the phytotoxic effects of purified CUL and CUL-trichothecene mixtures using Chlamydomonas reinhardtii growth and Triticum aestivum (wheat) root elongation assays. By itself, CUL did not affect growth in either system. However, mixtures of CUL with DON, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, or NX-3, but not with nivalenol, inhibited growth in a synergistic manner. Synergistic phytotoxic effects of CUL and DON were also observed on multiple plant varieties and species. The severity of wheat FHB caused by 15 isolates of Fusarium graminearum was negatively correlated with the CUL/DON ratio, but positively correlated with the sum of both CUL and DON. Additionally, during the first week of infection, CUL biosynthetic genes were more highly expressed than the TRI5 trichothecene biosynthetic gene. Furthermore, genomic analysis of Fusarium species revealed that CUL and trichothecene biosynthetic genes consistently co-occur among species closely related to F. graminearum.

Advances in understanding the epidemiology of Fusarium in cereals

2021 ◽  
pp. 83-110
Author(s):  
Stephen N. Wegulo ◽  
Keyword(s):  
Plant Pathogens ◽  
Fusarium Species ◽  
Management Strategies ◽  
Economic Security ◽  
Economic Losses ◽  
Cereal Crops ◽  
Calorie Intake ◽  
Head Blight ◽  
Fusarium Graminearum Species Complex ◽  
Daily Calorie Intake

Cereal grains contribute more than half of the global daily calorie intake. However, cereal crops are prone to attack by plant pathogens that cause devastating losses estimated in the billions of dollars, threatening global food and economic security. One of the diseases of small grain cereals that is of major economic importance is Fusarium head blight (FHB). It affects all small grain cereals, but major economic losses occur in wheat and barley production. FHB is caused mainly by Fusarium species in the Fusarium graminearum species complex, of which F. graminearum is the predominant causal agent. Understanding the epidemiology of F. graminearum is critical to the development of effective and sustainable FHB management strategies that will reduce or prevent losses. This chapter reviews recent advances in the epidemiology of F. graminearum in cereal crops.

scholarly journals Survey of Fusarium Species Associated with Fusarium Head Blight of Spring Wheat (Triticum aestivum) in Southeastern Idaho

2018 ◽  
Vol 19 (2) ◽  
pp. 125-127 ◽  
Author(s):  
Kaitlyn M. Bissonnette ◽  
Philip Wharton ◽  
Jianli Chen ◽  
Juliet M. Marshall
Keyword(s):  
Triticum Aestivum ◽  
Fusarium Head Blight ◽  
Spring Wheat ◽  
Management Practices ◽  
Fusarium Species ◽  
Fusarium Culmorum ◽  
Head Blight ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Species Specific

In Idaho, losses due to Fusarium head blight (FHB) of spring wheat (Triticum aestivum) have been infrequent and have historically been dominated by Fusarium culmorum (Wm. G. Sm.) Sacc. However, the incidence of FHB and deoxynivalenol-contaminated grain has increased in spring wheat in southeastern Idaho since 2009, indicating that other species of Fusarium may be contributing to disease. In 2011 and 2012, 17 spring wheat fields were scouted and sampled for FHB in southern Idaho. Contaminated grains were cultured, and putative Fusarium isolates were identified using species-specific polymerase chain reaction. In 2011, 87% of all recovered isolates were identified as F. graminearum, whereas only 13% were identified as F. culmorum. Of the isolates collected in 2012, 51% were identified as F. graminearum and 49% as F. culmorum. In both years, more F. graminearum isolates were recovered as compared to a survey conducted in 1984. Implementation of effective disease management practices will be necessary to minimize the establishment and spread of F. graminearum–responsible FHB in southeastern Idaho.

scholarly journals Apicidin biosynthesis is linked to accessory chromosomes in Fusarium poae isolates

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Thomas E. Witte ◽  
Linda J. Harris ◽  
Hai D. T. Nguyen ◽  
Anne Hermans ◽  
Anne Johnston ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Crop Yields ◽  
High Resolution Mass Spectrometry ◽  
Gene Clusters ◽  
Biosynthetic Gene ◽  
Metabolome Analysis ◽  
Head Blight ◽  
Eastern Canada ◽  
Fusarium Poae ◽  
Accessory Chromosomes

Abstract Background Fusarium head blight is a disease of global concern that reduces crop yields and renders grains unfit for consumption due to mycotoxin contamination. Fusarium poae is frequently associated with cereal crops showing symptoms of Fusarium head blight. While previous studies have shown F. poae isolates produce a range of known mycotoxins, including type A and B trichothecenes, fusarins and beauvericin, genomic analysis suggests that this species may have lineage-specific accessory chromosomes with secondary metabolite biosynthetic gene clusters awaiting description. Methods We examined the biosynthetic potential of 38 F. poae isolates from Eastern Canada using a combination of long-read and short-read genome sequencing and untargeted, high resolution mass spectrometry metabolome analysis of extracts from isolates cultured in multiple media conditions. Results A high-quality assembly of isolate DAOMC 252244 (Fp157) contained four core chromosomes as well as seven additional contigs with traits associated with accessory chromosomes. One of the predicted accessory contigs harbours a functional biosynthetic gene cluster containing homologs of all genes associated with the production of apicidins. Metabolomic and genomic analyses confirm apicidins are produced in 4 of the 38 isolates investigated and genomic PCR screening detected the apicidin synthetase gene APS1 in approximately 7% of Eastern Canadian isolates surveyed. Conclusions Apicidin biosynthesis is linked to isolate-specific putative accessory chromosomes in F. poae. The data produced here are an important resource for furthering our understanding of accessory chromosome evolution and the biosynthetic potential of F. poae.

Genetic relationships between resistances to Fusarium head blight and crown rot in bread wheat (Triticum aestivum L.)

2010 ◽  
Vol 121 (5) ◽  
pp. 941-950 ◽  
Author(s):  
Hao Bing Li ◽  
Guo Qiang Xie ◽  
Jun Ma ◽  
Gui Ru Liu ◽  
Shu Min Wen ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Fusarium Head Blight ◽  
Bread Wheat ◽  
Genetic Relationships ◽  
Triticum Aestivum L ◽  
Crown Rot ◽  
Head Blight

Effectiveness of fungicide seed treatments for preventing seed-to-seedling transmission of Fusarium graminearum under controlled-environment conditions

2009 ◽  
Vol 89 (4) ◽  
pp. 811-821 ◽  
Author(s):  
M R Fernandez ◽  
T K Turkington ◽  
W E May
Keyword(s):  
Fusarium Graminearum ◽  
Plant Tissue ◽  
Seedling Emergence ◽  
Wheat Root ◽  
Crown Rot ◽  
Controlled Environment ◽  
Wheat Seed ◽  
Seed Treatments ◽  
Head Blight ◽  
Infected Seed

Fusarium head blight (FHB) is well established in the eastern prairies, but for the most part it has been absent from western regions, especially under dryland conditions. This has been largely attributed to dry and hot conditions during some years, and the limited occurrence of F. graminearum in the western prairies. It is of importance to prevent the movement of F. graminearum, the most important FHB pathogen in North America, to areas where this pathogen is not commonly found. Three controlled-environment studies, using different Fusarium-infected common and durum wheat seed lots, were conducted to determine the effectiveness of currently registered fungicide seed treatments in improving seedling emergence and plant development, and preventing the growth of F. graminearum from infected seed to plant tissue. Fungicide treatments improved seedling emergence from the most infected seed over the untreated infected control, but most treatments did not improve emergence in the other experiments. Plant growth in the fungicide treatments was either similar to or slower than in the untreated controls. Fusarium graminearum was isolated from discoloured tissue in all treatments and was generally more common in crowns than in subcrown internodes. No fungicide treatment reduced discolouration of plant tissue or percentage isolation of F. graminearum or other Fusarium spp. consistently. We conclude that while currently registered seed treatments might be effective in improving seedling emergence in some infected wheat seed lots, they do not prevent the growth of F. graminearum from seeds to plant tissue. For the western prairies, the use of fungicide seed treatments as a strategy in the prevention of spread of FHB would require that they be effective primarily against F. graminearum. Performance of fungicide seed treatments against Fusarium-infected wheat seed should also be determined under typical growing conditions across the western prairies.Key words: Seed treatments, fungicides, wheat, root rot, crown rot, Fusarium graminearum, Fusarium avenaceum

Sadash soft white spring wheat

2009 ◽  
Vol 89 (6) ◽  
pp. 1099-1106 ◽  
Author(s):  
R S Sadasivaiah ◽  
R J Graf ◽  
H S Randhawa ◽  
B L Beres ◽  
S M Perkovic ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Spring Wheat ◽  
Triticum Aestivum L ◽  
Quality Analysis ◽  
Head Blight ◽  
Cultivar Description ◽  
Quality Specifications ◽  
Soft White Spring Wheat ◽  
End Use

Sadash is a soft white spring wheat (Triticum aestivum L.) that meets the end-use quality specifications of the Canada Western Soft White Spring class. Sadash is well-adapted to the wheat-growing regions of southern Alberta and southern Saskatchewan. Based on data from the Western Soft White Spring Wheat Cooperative Registration Test from 2003 to 2005, Sadash exhibited high grain yield, mid-season maturity, semi-dwarf stature with very strong straw, and good resistance to shattering. Sadash expressed resistance to the prevalent races of stem rust and powdery mildew, intermediate resistance to loose smut, moderate susceptibility to leaf rust and common bunt, and susceptibility to Fusarium head blight. Based on end-use quality analysis performed at the Grain Research Laboratory of the Canadian Grain Commission, Sadash had improved test weight over the check cultivars AC Reed and AC Phil and similar milling and baking performance.Key words: Triticum aestivum L., cultivar description, wheat (soft white spring), grain yield, quality, disease resistance

scholarly journals Multiwalled carbon nanotubes in alfalfa and wheat: toxicology and uptake

2012 ◽  
Vol 9 (77) ◽  
pp. 3514-3527 ◽  
Author(s):  
Pola Miralles ◽  
Errin Johnson ◽  
Tamara L. Church ◽  
Andrew T. Harris
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Root Elongation ◽  
Wheat Root ◽  
Root Tip ◽  
Multiwalled Carbon ◽  
Wheat Seedlings ◽  
Industrial Grade ◽  
High Concentrations ◽  
Multiwalled Cnts

Data on the bioavailability and toxicity of carbon nanotubes (CNTs) in the environment, and, in particular, on their interactions with vascular plants, are limited. We investigated the effects of industrial-grade multiwalled CNTs (75 wt% CNTs) and their impurities on alfalfa and wheat. Phytotoxicity assays were performed during both seed germination and seedling growth. The germinations of both species were tolerant of up to 2560 mg l −1 CNTs, and root elongation was enhanced in alfalfa and wheat seedlings exposed to CNTs. Remarkably, catalyst impurities also enhanced root elongation in alfalfa seedlings as well as wheat germination. Thus the impurities, not solely the CNTs, impacted the plants. CNT internalization by plants was investigated using electron microscopy and two-dimensional Raman mapping. The latter showed that CNTs were adsorbed onto the root surfaces of alfalfa and wheat without significant uptake or translocation. Electron microscopy investigations of internalization were inconclusive owing to poor contrast, so Fe 3 O 4 -functionalized CNTs were prepared and studied using energy-filter mapping of Fe 3 O 4 . CNTs bearing Fe 3 O 4 nanoparticles were detected in the epidermis of one wheat root tip only, suggesting that internalization was possible but unusual. Thus, alfalfa and wheat tolerated high concentrations of industrial-grade multiwalled CNTs, which adsorbed onto their roots but were rarely taken up.

scholarly journals Refactoring the formicamycin biosynthetic gene cluster to make high-level producing strains and new molecules

2020 ◽  
Author(s):  
Rebecca Devine ◽  
Hannah McDonald ◽  
Zhiwei Qin ◽  
Corinne Arnold ◽  
Katie Noble ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Large Scale ◽  
Liquid Culture ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Biosynthetic Gene ◽  
Biosynthetic Genes

AbstractThe formicamycins are promising antibiotics with potent activity against Gram-positive pathogens including VRE and MRSA and display a high barrier to selection of resistant isolates. They were first identified in Streptomyces formicae KY5, which produces the formicamycins at low levels on solid agar but not in liquid culture, thus hindering further investigation of these promising antibacterial compounds. We hypothesised that by understanding the organisation and regulation of the for biosynthetic gene cluster, we could rationally refactor the cluster to increase production levels. Here we report that the for biosynthetic gene cluster consists of 24 genes expressed on nine transcripts. Seven of these transcripts, including those containing all the major biosynthetic genes, are repressed by the MarR-regulator ForJ which also controls the expression of the ForGF two-component system that initiates biosynthesis. A third cluster-situated regulator, ForZ, autoregulates and controls production of the putative MFS transporter ForAA. Consistent with these findings, deletion of forJ increased formicamycin biosynthesis 5-fold, while over-expression of forGF in the ΔforJ background increased production 10-fold compared to the wild-type. De-repression by deleting forJ also switched on biosynthesis in liquid-culture and induced the production of two novel formicamycin congeners. By combining mutations in regulatory and biosynthetic genes, six new biosynthetic precursors with antibacterial activity were also isolated. This work demonstrates the power of synthetic biology for the rational redesign of antibiotic biosynthetic gene clusters both to engineer strains suitable for fermentation in large scale bioreactors and to generate new molecules.ImportanceAntimicrobial resistance is a growing threat as existing antibiotics become increasingly ineffective against drug resistant pathogens. Here we determine the transcriptional organisation and regulation of the gene cluster encoding biosynthesis of the formicamycins, promising new antibiotics with activity against drug resistant bacteria. By exploiting this knowledge, we construct stable mutant strains which over-produce these molecules in both liquid and solid culture whilst also making some new compound variants. This will facilitate large scale purification of these molecules for further study including in vivo experiments and the elucidation of their mechanism of action. Our work demonstrates that understanding the regulation of natural product biosynthetic pathways can enable rational improvement of the producing strains.

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