Phytotoxic Compounds produced by<i>Fusarium equiseti</i>

Brian, P. W.; Dawkins, A. W.; Grove, John Frederick; Hemming, H. G.; Lowe, Deirdre P.; Norris, Grace

doi:10.1093/jxb/12.1.1

Cited by 180 publications

(66 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Mycelia for DNA extraction were grown for 18 h at 37°C in Sabouraud medium (2% glucose and 1% mycopeptone; Biokar). The defined medium used was Brian's medium (3). Growth inhibition studies were conducted with defined RPMI medium (Sigma) supplemented with glutamine (0.3 mg/ml) (RPMI-glu) on microtiter plates.…”

Section: Methodsmentioning

confidence: 99%

“…In this fungal species, ␣(1-3) glucan synthesis is controlled by a single gene, AGS1 [for ␣ (1)(2)(3) glucan synthase], which is an essential gene (12,15). ␣(1-3) glucan synthesis is essential for correct cell wall morphogenesis, since the mutant ⌬ags1 with a reduced ␣(1-3) glucan in its cell wall shows a loss of cell polarity at restrictive temperatures (12,15).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Two α(1-3) Glucan Synthases with Different Functions in Aspergillus fumigatus

Beauvais

Maubon

Park³

et al. 2005

Appl Environ Microbiol

122

121

View full text Add to dashboard Cite

␣(1-3) glucan is a main component of the Aspergillus fumigatus cell wall. In spite of its importance, synthesis of this amorphous polymer has not been investigated to date. Two genes in A. fumigatus, AGS1 and AGS2, are highly homologous to the AGS genes of Schizosaccharomyces pombe, which encode putative ␣(1-3) glucan synthases. The predicted Ags proteins of A. fumigatus have an estimated molecular mass of 270 kDa. AGS1 and AGS2 were disrupted in A. fumigatus. Both ⌬ags mutants have similar altered hyphal morphologies and reduced conidiation levels. Only ⌬ags1 presented a reduction in the ␣(1-3) glucan content of the cell wall. These results showed that Ags1p and Ags2p were functionally different. The cellular localization of the two proteins was in agreement with their different functions: Ags1p was localized at the periphery of the cell in connection with the cell wall, whereas Ags2p was intracellularly located. An original experimental model of invasive aspergillosis based on mixed infection and quantitative PCR was developed to analyze the virulence of A. fumigatus mutant and wild-type strains. Using this model, it was shown that the cell wall and morphogenesis defects of ⌬ags1 and ⌬ags2 were not associated with a reduction in virulence in either mutant. This result showed that a 50% reduction in the content of the cell wall ␣(1-3) glucan does not play a significant role in A. fumigatus pathogenicity.The fungal cell wall of Aspergillus fumigatus is mainly composed of polysaccharides that can be separated into two fractions, depending on their solubility in hot sodium hydroxide (7). The alkali-insoluble (AI) fraction constitutes the wall skeleton. It is composed of a branched ␤(1-3) glucan to which are attached chitin, ␤(1-3) and ␤(1-4) glucan, and galactomannan (7). The alkali-soluble (AS) fraction contains mainly ␣(1-3) glucans and galactomannan (1). Galactomannan has been shown to be associated with host immune reactions against A. fumigatus (18). In A. fumigatus, ␣(1-3) glucan is the major polysaccharide of the cell wall (40% [dry weight] of the cell wall) (7). The role of ␣(1-3) glucan in A. fumigatus pathogenicity has not been investigated, although its role in virulence has been demonstrated in Histoplasma capsulatum, Paracoccidioides brasiliensis, and Blastomyces dermatitidis. In these species, mutants with a reduction of ␣(1-3) glucan in their cell wall are avirulent (13,16,30). The construction of a mutant with a reduced amount of ␣(1-3) glucan in the cell wall of A. fumigatus and the study of its virulence in a mouse model are the aims of this paper.The synthesis of ␣(1-3) glucan has been studied only in Schizosaccharomyces pombe. In this fungal species, ␣(1-3) glucan synthesis is controlled by a single gene, AGS1 [for ␣(1-3) glucan synthase], which is an essential gene (12, 15). ␣(1-3) glucan synthesis is essential for correct cell wall morphogenesis, since the mutant ⌬ags1 with a reduced ␣(1-3) glucan in its cell wall shows a loss of cell polarity at restrictive temperatures (12,15).In this paper...

show abstract

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

Two α(1-3) Glucan Synthases with Different Functions in Aspergillus fumigatus

Beauvais

Maubon

Park³

et al. 2005

Appl Environ Microbiol

122

121

View full text Add to dashboard Cite

show abstract

“…The first trichothecene to be isolated was trichothecin from Trichotheceum roseum, in 1948 by Freeman and Morrison [210]. Diacetoxyscirpenol (DAS) from Fusarium equiseti was preliminarily characterized in 1961 by Brian et al [211], and was later followed by nivalenol (NIV) [212] and T-2 toxin [213], both from F. sporotrichioides, although they were mis-identified as F. nivale and F. tricinctum, respectively, in the original articles [214]. However, it was the discovery of 4-deoxynivalenol (DON) from wheat in Eastern North America in 1980 [215], which truly sparked the research into the Fusarium species and led to the discovery of trichothecenes from other genera.…”

Section: Historical Perspective and Producing Fungal Speciesmentioning

confidence: 99%

Mycotoxins: Producing Fungi and Mechanisms of Phytotoxicity

2015

View full text Add to dashboard Cite

Abstract:Mycotoxins are secondary fungal metabolites, toxic to humans, animals and plants. Among the hundreds of known mycotoxins, aflatoxins, citrinin, patulin, penicillic acid, tenuazonic acid, ochratoxin A, cytochalasins, deoxynivalenol, fumonisins, fusarin C, fusaric acid, and zearalenone are considered the types that most contaminate cereal grain. The majority of the mycotoxins in these groups are produced by three fungal genera: Aspergillus, Penicillium and Fusarium. These metabolites primarily affect the seed quality, germination, viability, seedling vigour, growth of root and cleoptile. Additionally, since the fungi responsible for the production of these mycotoxins are often endophytes that infect and colonize living plant tissues, accumulation of mycotoxins in the plant tissues may at times be associated with development of plant disease symptoms. The presence of mycotoxins, even in the absence of disease symptoms, may still have subtle biological effects on the physiology of plants. Several studies highlight the toxic effects of mycotoxins on animals and cell lines but little is known about the mode of action of most of these metabolites on plant cells. The most important mycotoxins with phytotoxic effects and their producers in addition to their discovery are briefly outlined below and will be addressed in this article.

show abstract

“…Three defined media were preassayed in terms of their suitability to VOC analysis: Brian's broth (16), AMM (17), and RPMI 1640 (Sigma-Aldrich) supplemented with 0.3 g/liter glutamine and buffered to pH 7.0 with 0.165 M morpholinepropanesulfonic acid (MOPS; Sigma-Aldrich) (18 4 . The pH was set to 5.4.…”

Section: Strainsmentioning

confidence: 99%

The Volatome of Aspergillus fumigatus

2014

View full text Add to dashboard Cite

bEarly detection of invasive aspergillosis is absolutely required for efficient therapy of this fungal infection. The identification of fungal volatiles in patient breath can be an alternative for the detection of Aspergillus fumigatus that still remains problematic. In this work, we investigated the production of volatile organic compounds (VOCs) by A. fumigatus in vitro, and we show that volatile production depends on the nutritional environment. A. fumigatus produces a multiplicity of VOCs, predominantly terpenes and related compounds. The production of sesquiterpenoid compounds was found to be strongly induced by increased iron concentrations and certain drugs, i.e., pravastatin. Terpenes that were always detectable in large amounts were ␣-pinene, camphene, and limonene, as well as sesquiterpenes, identified as ␣-bergamotene and ␤-trans-bergamotene. Other substance classes that were found to be present in the volatome, such as 1-octen-3-ol, 3-octanone, and pyrazines, were found only under specific growth conditions. Drugs that interfere with the terpene biosynthesis pathway influenced the composition of the fungal volatome, and most notably, a block of sesquiterpene biosynthesis by the bisphosphonate alendronate fundamentally changed the VOC composition. Using deletion mutants, we also show that a terpene cyclase and a putative kaurene synthase are essential for the synthesis of volatile terpenes by A. fumigatus. The present analysis of in vitro volatile production by A. fumigatus suggests that VOCs may be used in the diagnosis of infections caused by this fungus.A spergillus fumigatus is an opportunistic fungal pathogen that causes life-threatening invasive pulmonary infections (invasive aspergillosis [IA]) among immunocompromised patients. A sensitive, rapid, and accurate diagnostic assay for invasive aspergillosis is required to successfully fight this fungal infection (1). It has recently been proposed that the detection of volatiles can be used for the diagnosis of pulmonary infections (2, 3) and lung cancer (4, 5). Several aspergilli, including A. flavus, A. ustus, and A. versicolor, have been identified within the scope of environmental studies, where room air was analyzed to detect fungal pollution in houses (6-8). 2-Pentylfuran (2-PF) was detected in the breath of patients with A. fumigatus infection (9). It was shown that A. fumigatus produces farnesene when grown in vitro (10), and the use of terpene volatiles for the detection of IA has recently been proposed (11). However, the spectrum of volatile organic compounds (VOCs) produced by A. fumigatus and their synthesis have been poorly described. In this work, we characterized the patterns of volatile terpenes produced in vitro by A. fumigatus during growth under saprophytic conditions. In addition, the molecular pathways responsible for the synthesis of terpenoid volatiles were defined. MATERIALS AND METHODS Strains.Aspergillus fumigatus strain FGSC A1163 (ϭ DAL ϭ CBS144.89) was used for wild type strain-based experiments. Gene deletions were obta...

show abstract

Phytotoxic Compounds produced byFusarium equiseti

Cited by 180 publications

References 12 publications

Two α(1-3) Glucan Synthases with Different Functions in Aspergillus fumigatus

Two α(1-3) Glucan Synthases with Different Functions in Aspergillus fumigatus

Mycotoxins: Producing Fungi and Mechanisms of Phytotoxicity

The Volatome of Aspergillus fumigatus

Contact Info

Product

Resources

About