Possible involvement of a pathogen-produced trichothecene metabolite in Myrothecium leaf spot of muskmelon

Kuti, J.O.; Ng, Timothy J; Bean, G. A.

doi:10.1016/0885-5765(89)90015-5

Cited by 25 publications

(14 citation statements)

References 18 publications

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“…This may result from a lower membrane permeability or perhaps to more efficient binding of DON to the plasmalemma (or cell wall), effectively reducing the availability of toxin molecules. Other researchers have reported membrane-associated involvement in resistance to trichothecenes [152,153]. Muskmelon plants (Cucumis melo) resistant to Myrothecium roridum exhibited a reduced electrolyte loss, generally caused by roridin E, a macrocyclic trichothecene [153].…”

Section: Toxin Tolerance or Degradationmentioning

confidence: 97%

The phytotoxicity ofFusarium metabolites: An update since 1989

McLean

1996

Mycopathologia

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The present article summarises the published phytotoxic effects of severalFusarium metabolites (mycotoxins, phytotoxins, antibiotics and pigments) since 1989. The phytotoxicity of many of the commonly isolated metabolites cannot be disputed, but their role in pathogenesis ofFusarium-induced plant diseases is uncertain. Plant species/varieties differ in their susceptibililty resistance to these toxinsin vitro, as well as toFusarium pathogens under field conditions. Such variations in plant response may reflect resistance mechanisms that operate at several levels, including an initial ability to prevent fungal invasion; prevention of fungal spread and toxin tolerance or degradation. Little is known about the mode of action of most of these metabolites on either animal or plant cells. Several novelFusarium metabolites have been isolated in the past few years. Many are toxic to animals and cell lines, but assessment of their phytotoxicity has largely been neglected. Since many plant pathogenic Fusaria produce a plethora of metabolites, the additive or synergistic actions of toxins in combination must be considered in plant pathology.

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Section: Toxin Tolerance or Degradationmentioning

confidence: 97%

The phytotoxicity ofFusarium metabolites: An update since 1989

McLean

1996

Mycopathologia

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“…T-2 toxin, diacetoxyscirpenol, and deoxynivalenol) and macrocylic trichothecenes such as the verrucarins and roridins which are mainly produced by Myrothecium species (Cutler and Jarvis, 1985). Kuti et al (1989) mentioned the possible involvement of a pathogenproduced trichothecenes, such as verrucarins and roridins from Myrothecium, in leaf spot of muskmelon. A combination of two pathogens, Cercospora and Myrothecium species, is being evaluated as a potential bioherbicide for the water hyacinth, Eichhornia crassipes (Mart.)…”

Section: Discussionmentioning

confidence: 99%

“…Macrocyclic trichothecenes are undetectable in kudzu (Pueraria montana) plants treated with M. verrucaria. It has been known that trichothecenes exhibit varied biological activities such as antifungal, cytotoxic, and phytotoxic effects (Cunfer and Lukezic, 1979;Kuti et al, 1989). The trichothecenes are normally divided into two broad categories: non-macrocylic trichothecenes (e.g.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of a Fungal Strain, Myrothecium roridum F0252, as a Bioherbicide Agent

Lee¹,

Kim²,

Hong³

et al. 2008

The Plant Pathology Journal

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In the course of in vitro and in vivo screening for bioherbicidal agents, a hyphomycete fungus, Myrothecium sp. F0252 was selected as a candidate for the biocontrol of weeds. The isolate was identified as Myrothecium roridum Tode ex. Fries based on the morphological characteristics and 18S ribosomal DNA sequence analysis and registered as Myrothecium roridum F0252. In order to evaluate the in vitro effect of M. roridum F0252 on germination of ladino clover and white clover (Trifolium repens L.) seeds, spore solution of the fungus was employed in two concentrations, 6.5×10 6 and 2.5× 10 7 spores per mL and then inoculated to the seeds. The fungal spores inhibited the seed germination, infected the seedlings, and caused an abnormal withering and inhibition of seedling growth. In addition, when the herbicidal activity of crude ethyl acetate extract from the liquid culture was assessed on a mini-plant, duckweed (Lemna paucicostata (L.) Hegelm.), the extract showed high inhibitory effect at the level of 12.5 µg per mL. On the other hand, in vivo herbicidal activity of M. roridum F0252 was evaluated by a whole plant spray method. M. roridum F0252 exhibited strong and broadspectrum herbicidal activity. The herbicidal values ranged from 95-100% against 7 weeds, including Abutilon avicennae and Xanthium strumarium, and 70-80% against Digitaria sanguinalis and Sagittaria pygmaea. When the nutritional utilization (95 carbon sources) pattern of M. roridum F0252 was investigated, it varied with water activity (a w ) and temperature conditions, supplying good, basic information in regard to nutritional utilization for proper cultivation and formulation. Our results showed that M. roridum F0252 might be used as a potential biocontrol agent against weedy plants.

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“…It has been proposed that macrocyclic trichothecenes may play a role in some plant diseases (Kuti et al 1989;Bean et al 1994) and may also act as toxic environmental contaminants (Montana et al 1995). The availability of genes of the macrocyclic pathway provides an opportunity to investigate these questions and to further characterize macrocyclic trichothecene biosynthesis.…”

Section: Discussionmentioning

confidence: 98%

“…Many trichothecene-producing fungi are plant pathogens, and it has been hypothesized that the trichothecenes serve a function in plant disease Proctor et al 1995a). In this regard, Myrothecium roridum has been implicated in muskmelon pathogenicity (Bean et al 1984;Kuti et al 1989). …”

Section: Introductionmentioning

confidence: 98%

Characterization of the gene cluster for biosynthesis of macrocyclic trichothecenes in Myrothecium roridum

et al. 1998

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Macrocyclic trichothecenes are toxic sesquiterpenoids that are produced by certain fungi and plants. The unique structural features of macrocyclic trichothecenes result in increased toxicity relative to other trichothecene structural types. Here we report the sequences and relative locations of the MRTRI5, MRTRI6, and MRTRI4 genes in the biosynthetic pathway for macrocyclic trichothecenes in Myrothecium roridum. The deduced sequences of the products of MRTRI5 and MRTRI4 display overall identities of 75 and 63%, respectively, with the corresponding proteins in Fusarium sporotrichioides. Based on sequence comparisons, MRTRI5 encodes the enzyme trichodiene synthase, which has been shown to catalyze the first step in the trichothecene pathways of Fusarium and Trichothecium species. MRTRI6 encodes a transcription factor (392 amino acids) required for pathway gene expression, and the predicted MRTRI4 product (533 amino acids) is a cytochrome P450 monooxygenase responsible for the initial oxygenation step in the pathway. The sizes of the predicted products of MRTRI5 and MRTRI4 show good agreement with their apparent counterparts in the Fusarium pathway; however, the protein specified by MRTRI6 is almost twice the size of its putative homolog in F. sporotrichioides. Only the C-terminal 124 residues of MRTRI6, containing the proposed Cys2His2 zinc finger motifs, show significant similarity (65% identity) to the TRI6 sequence in F. sporotrichioides. MRTRI4 can successfully complement a TRI4-mutant in F. sporotrichioides, although the resulting trichothecene profile differed from that observed in wild-type strains. Complemented mutants accumulated low levels of T-2 toxin, in addition to sambucinol, deoxysambucinol, and the pathway intermediates trichothecene and isotrichodiol. Mapping data indicate that the genes of the macrocyclic trichothecene pathway in M. roridum are clustered, but that their organization and orientation differ markedly from those of the trichothecene gene cluster found in F. sporotrichioides. These results show that the biosynthetic pathways for macrocyclic trichothecenes are closely related to other trichothecene pathways and that the evolution of gene clusters for the biosynthesis of natural products in fungi can involve significant rearrangements.

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Possible involvement of a pathogen-produced trichothecene metabolite in Myrothecium leaf spot of muskmelon

Cited by 25 publications

References 18 publications

The phytotoxicity ofFusarium metabolites: An update since 1989

The phytotoxicity ofFusarium metabolites: An update since 1989

Evaluation of a Fungal Strain, Myrothecium roridum F0252, as a Bioherbicide Agent

Characterization of the gene cluster for biosynthesis of macrocyclic trichothecenes in Myrothecium roridum

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