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LDS1-produced oxylipins are negative regulators of growth, conidiation and fumonisin synthesis in the fungal maize pathogen Fusarium verticillioides.

Scala V, Giorni P, Cirlini M, Ludovici M, Visentin I, Cardinale F, Fabbri AA, Fanelli C, Reverberi M, Battilani P, Galaverna G, Dall'Asta C - Front Microbiol (2014)

Bottom Line: Among the many enzymes responsible for oxylipin generation, Linoleate Diol Synthase 1 (LDS1) produces mainly 8-hydroperoxyoctadecenoic acid and subsequently different di-hydroxyoctadecenoic acids.In this study, we inactivated a copy of the putative LDS1 ortholog (acc.We hypothesize that oxylipins may act as regulators of gene expression in the toxigenic plant pathogen F. verticillioides, in turn causing notable changes in its phenotype.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Biology, University of Rome "Sapienza" Rome, Italy.

ABSTRACT
Oxylipins are fatty acid-derived signaling compounds produced by all eukaryotes so far investigated; in mycotoxigenic fungi, they modulate toxin production and interactions with the host plants. Among the many enzymes responsible for oxylipin generation, Linoleate Diol Synthase 1 (LDS1) produces mainly 8-hydroperoxyoctadecenoic acid and subsequently different di-hydroxyoctadecenoic acids. In this study, we inactivated a copy of the putative LDS1 ortholog (acc. N. FVEG_09294.3) of Fusarium verticillioides, with the aim to investigate its influence on the oxylipin profile of the fungus, on its development, secondary metabolism and virulence. LC-MS/MS oxylipin profiling carried out on the selected mutant strain revealed significant quali-quantitative differences for several oxylipins when compared to the WT strain. The Fvlds1-deleted mutant grew better, produced more conidia, synthesized more fumonisins and infected maize cobs faster than the WT strain. We hypothesize that oxylipins may act as regulators of gene expression in the toxigenic plant pathogen F. verticillioides, in turn causing notable changes in its phenotype. These changes could relate to the ability of oxylipins to re-shape the transcriptional profile of F. verticillioides by inducing chromatin modifications and exerting a direct control on the transcription of secondary metabolism in fungi.

No MeSH data available.


Related in: MedlinePlus

Relative acetylation levels of the FUM1 gene promoter (PFUM1) in F. verticillioides WT and ΔFvlds1D strains. Acetylation levels were analyzed by ChIP with antibodies specific to hyper-acetylated histone H4 on DNA from fungi cultured in FB-inducing CDYM. The abundance of target DNA was quantified by the comparative CT method with β-TUB as the endogenous reference for normalization. Error bars indicate the standard errors of two biological and three technical repetitions.
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Figure 6: Relative acetylation levels of the FUM1 gene promoter (PFUM1) in F. verticillioides WT and ΔFvlds1D strains. Acetylation levels were analyzed by ChIP with antibodies specific to hyper-acetylated histone H4 on DNA from fungi cultured in FB-inducing CDYM. The abundance of target DNA was quantified by the comparative CT method with β-TUB as the endogenous reference for normalization. Error bars indicate the standard errors of two biological and three technical repetitions.

Mentions: We previously showed that FB levels are enhanced in oxylipin-defective mutants of F. verticillioides because of transcription activation (see FBtot and FUM1 transcript quantification in Figures 3A,B, for comparison). We speculated that this may be ascribed to altered acetylation levels of histone proteins at PFUM1, as reported under FB-inducing conditions for another WT strain of F. verticillioides (Visentin et al., 2012). To test this hypothesis, we performed a chromatin immunoprecipitation (ChIP) assay with a commercial antibody targeted to the hyper-acetylated form of histone H4 and focused our analysis on PFUM1 of the WT and ΔFvlds1D strains grown in FB-inducing medium (CDYM). The quantities of immunoprecipitated DNA fragments containing PFUM1 were significantly (p < 0.001) greater in the ΔFvlds1D than in the WT strain (Figure 6). This result suggests a role for oxylipins in modulating the expression of gene(s) in the FUM cluster at the chromatin level.


LDS1-produced oxylipins are negative regulators of growth, conidiation and fumonisin synthesis in the fungal maize pathogen Fusarium verticillioides.

Scala V, Giorni P, Cirlini M, Ludovici M, Visentin I, Cardinale F, Fabbri AA, Fanelli C, Reverberi M, Battilani P, Galaverna G, Dall'Asta C - Front Microbiol (2014)

Relative acetylation levels of the FUM1 gene promoter (PFUM1) in F. verticillioides WT and ΔFvlds1D strains. Acetylation levels were analyzed by ChIP with antibodies specific to hyper-acetylated histone H4 on DNA from fungi cultured in FB-inducing CDYM. The abundance of target DNA was quantified by the comparative CT method with β-TUB as the endogenous reference for normalization. Error bars indicate the standard errors of two biological and three technical repetitions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC4263177&req=5

Figure 6: Relative acetylation levels of the FUM1 gene promoter (PFUM1) in F. verticillioides WT and ΔFvlds1D strains. Acetylation levels were analyzed by ChIP with antibodies specific to hyper-acetylated histone H4 on DNA from fungi cultured in FB-inducing CDYM. The abundance of target DNA was quantified by the comparative CT method with β-TUB as the endogenous reference for normalization. Error bars indicate the standard errors of two biological and three technical repetitions.
Mentions: We previously showed that FB levels are enhanced in oxylipin-defective mutants of F. verticillioides because of transcription activation (see FBtot and FUM1 transcript quantification in Figures 3A,B, for comparison). We speculated that this may be ascribed to altered acetylation levels of histone proteins at PFUM1, as reported under FB-inducing conditions for another WT strain of F. verticillioides (Visentin et al., 2012). To test this hypothesis, we performed a chromatin immunoprecipitation (ChIP) assay with a commercial antibody targeted to the hyper-acetylated form of histone H4 and focused our analysis on PFUM1 of the WT and ΔFvlds1D strains grown in FB-inducing medium (CDYM). The quantities of immunoprecipitated DNA fragments containing PFUM1 were significantly (p < 0.001) greater in the ΔFvlds1D than in the WT strain (Figure 6). This result suggests a role for oxylipins in modulating the expression of gene(s) in the FUM cluster at the chromatin level.

Bottom Line: Among the many enzymes responsible for oxylipin generation, Linoleate Diol Synthase 1 (LDS1) produces mainly 8-hydroperoxyoctadecenoic acid and subsequently different di-hydroxyoctadecenoic acids.In this study, we inactivated a copy of the putative LDS1 ortholog (acc.We hypothesize that oxylipins may act as regulators of gene expression in the toxigenic plant pathogen F. verticillioides, in turn causing notable changes in its phenotype.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Biology, University of Rome "Sapienza" Rome, Italy.

ABSTRACT
Oxylipins are fatty acid-derived signaling compounds produced by all eukaryotes so far investigated; in mycotoxigenic fungi, they modulate toxin production and interactions with the host plants. Among the many enzymes responsible for oxylipin generation, Linoleate Diol Synthase 1 (LDS1) produces mainly 8-hydroperoxyoctadecenoic acid and subsequently different di-hydroxyoctadecenoic acids. In this study, we inactivated a copy of the putative LDS1 ortholog (acc. N. FVEG_09294.3) of Fusarium verticillioides, with the aim to investigate its influence on the oxylipin profile of the fungus, on its development, secondary metabolism and virulence. LC-MS/MS oxylipin profiling carried out on the selected mutant strain revealed significant quali-quantitative differences for several oxylipins when compared to the WT strain. The Fvlds1-deleted mutant grew better, produced more conidia, synthesized more fumonisins and infected maize cobs faster than the WT strain. We hypothesize that oxylipins may act as regulators of gene expression in the toxigenic plant pathogen F. verticillioides, in turn causing notable changes in its phenotype. These changes could relate to the ability of oxylipins to re-shape the transcriptional profile of F. verticillioides by inducing chromatin modifications and exerting a direct control on the transcription of secondary metabolism in fungi.

No MeSH data available.


Related in: MedlinePlus