The 2012 crop year in north-east Italy was characterized by a strong heat-wave event, and areas i... more The 2012 crop year in north-east Italy was characterized by a strong heat-wave event, and areas influenced by this environmental condition presented an anomalous accumulation of mycotoxins in maize. Mycotoxins are secondary metabolites, harmful to human and animals, produced by pathogenic fungi that contaminate foodstuffs. Plants suffering by stress are characterized by lower crop yield and quality, increased fungal infection and in some cases by higher amounts of mycotoxins. In plant, heat-wave events and generally stress factors afflict physiological traits and are associated with oxidative stress. Since oxidative stress is fundamental also for activation of mycotoxin biosynthesis in fungi, stress conditions in plant and mycotoxin accumulation are often correlated. The present paper aims to report the influence of some stress factors in relation to mycotoxin accumulation providing further data to comprehension of stress management with particular emphasis to heat-wave related events.
ABSTRACT In northern Italy, the most frequently occurring class of mycotoxins in maize are fumoni... more ABSTRACT In northern Italy, the most frequently occurring class of mycotoxins in maize are fumonisins, mainly those produced by Fusarium verticillioides. Currently, good agricultural practices (GAPs) represent the best line of defense for controlling the contamination of maize by Fusarium-toxins. Annual fluctuations in weather conditions can strongly reduce the advantages conferred by GAPs, and thus integration with biological control strategies can be a sustainable way to achieve reliable control of Fusarium colonization and toxin contamination. Trichoderma harzianum is a good biocontrol agent against a wide range of plant pathogens, and previous studies have reported its ability to reduce F. verticillioides colonization under greenhouse conditions. Field trials were conducted in two locations to assess the effect of seed treatment with T. harzianum strain T22 on F. verticillioides kernel colonization and on fumonisin contamination under various natural conditions. An average reduction of 58% in fungal infestation and 53% in mycotoxin contamination was observed during our three-year experiments. This research suggests that seed biopriming with T. harzianum T22 can be a promising and environmentally friendly way to control F. verticillioides kernel colonization and fumonisin accumulation.
Microalgae provide one of the more promising strategies for the production of renewable biodiesel... more Microalgae provide one of the more promising strategies for the production of renewable biodiesel and liquid fuels. Coupling biodiesel production and wastewater treatment based on the use of microalgae can be an effective approach for achieving sustainable production. Several pilot programs aimed at lipid production are currently working with Acutodesmus obliquus, and companies offering algal inocula are increasing in number. A. obliquus strain RL01 was isolated from a pretreated leachate, and preliminary analyses indicated a high growth rate, a final biomass concentration of 1.9 g L -1 and a lipid content of 47% DW. With the aim of strictly differentiating and unequivocally identifying the new strain in comparison with other A. obliquus lipid producers available in culture collections, we employed a DNA barcoding approach, targeting conventional and non-conventional genome regions. Genomic analyses were performed using two internal transcribed spacers (nuclear ITS1 and ITS2 sequences) and three selected chloroplast regions (the trnL genic intron and the rpl20-psbA and psbM-psbZ intergenic spacers). Our findings raise some concerns about the discriminant power of the ITS2 nuclear target and place particular emphasis on the psbM-psbZ plastid DNA barcode, which is characterized by high polymorphism, for use in studies addressing intraspecific genetic diversity.
Fusarium verticillioides is one of the most common plant pathogenic fungi affecting maize causing... more Fusarium verticillioides is one of the most common plant pathogenic fungi affecting maize causing ear and kernel rot. Nearly the totality of the fungal strains are able to produce mycotoxins known as fumonisins at very different levels. However, information on the ability of the biocontrol fungus Trichoderma harzianum to induce systemic resistance in maize against F. verticillioides is still lacking. We now show that, upon root colonization by T. harzianum, F. verticillioides consistently reduces maize disease symptoms. The enhanced activation of SA- and JA/ ET-dependent defence responses indicates that resistance in maize is caused by a better perception of the fungal pathogen due to the effect of Trichoderma inocula. Seed biopriming with T. harzianum could be a useful strategy to control F. verticillioides infection and fumonisin accumulation under field conditions.
Microalgae provide one of the more promising strategies for the production of renewable biodiesel... more Microalgae provide one of the more promising strategies for the production of renewable biodiesel and liquid fuels. Coupling biodiesel production and wastewater treatment based on the use of microalgae can be an effective approach for achieving sustainable production. Several pilot programs aimed at lipid production are currently working with Acutodesmus obliquus, and companies offering algal inocula are increasing in number. A. obliquus strain RL01 was isolated from a pretreated leachate, and preliminary analyses indicated a high growth rate, a final biomass concentration of 1.9 g L -1 and a lipid content of 47% DW. With the aim of strictly differentiating and unequivocally identifying the new strain in comparison with other A. obliquus lipid producers available in culture collections, we employed a DNA barcoding approach, targeting conventional and non-conventional genome regions. Genomic analyses were performed using two internal transcribed spacers (nuclear ITS1 and ITS2 sequences) and three selected chloroplast regions (the trnL genic intron and the rpl20-psbA and psbM-psbZ intergenic spacers). Our findings raise some concerns about the discriminant power of the ITS2 nuclear target and place particular emphasis on the psbM-psbZ plastid DNA barcode, which is characterized by high polymorphism, for use in studies addressing intraspecific genetic diversity.
Journal of agricultural and food chemistry, Jan 20, 2015
The effects of oxidative stress induced by H2O2 were tested in liquid cultures in the fumonisin-p... more The effects of oxidative stress induced by H2O2 were tested in liquid cultures in the fumonisin-producing fungus Fusarium verticillioides. The quantitative analysis of fumonisins B1, B2, B3, and B4 was achieved by means of liquid chromatography coupled to high-resolution mass spectrometry. Two effects in F. verticillioides, consisting of different abilities to produce fumonisins in response to oxidative stress, were identified. Following H2O2 addition, two F. verticillioides strains produced significantly more fumonisin (>300%) while three other strains produced significantly less (<20%) in comparison to control cultures. Transcriptional studies with seven biosynthetic genes showed a significant increase in transcript levels in the strain that made more fumonisin and either no or minimal changes in the strain that made less fumonisin. Our data indicate the important role of oxidative stress toward the modulation of the fumonisin biosynthesis and suggest the necessity to verify...
The 2012 crop year in north-east Italy was characterized by a strong heat-wave event, and areas i... more The 2012 crop year in north-east Italy was characterized by a strong heat-wave event, and areas influenced by this environmental condition presented an anomalous accumulation of mycotoxins in maize. Mycotoxins are secondary metabolites, harmful to human and animals, produced by pathogenic fungi that contaminate foodstuffs. Plants suffering by stress are characterized by lower crop yield and quality, increased fungal infection and in some cases by higher amounts of mycotoxins. In plant, heat-wave events and generally stress factors afflict physiological traits and are associated with oxidative stress. Since oxidative stress is fundamental also for activation of mycotoxin biosynthesis in fungi, stress conditions in plant and mycotoxin accumulation are often correlated. The present paper aims to report the influence of some stress factors in relation to mycotoxin accumulation providing further data to comprehension of stress management with particular emphasis to heat-wave related events.
ABSTRACT In northern Italy, the most frequently occurring class of mycotoxins in maize are fumoni... more ABSTRACT In northern Italy, the most frequently occurring class of mycotoxins in maize are fumonisins, mainly those produced by Fusarium verticillioides. Currently, good agricultural practices (GAPs) represent the best line of defense for controlling the contamination of maize by Fusarium-toxins. Annual fluctuations in weather conditions can strongly reduce the advantages conferred by GAPs, and thus integration with biological control strategies can be a sustainable way to achieve reliable control of Fusarium colonization and toxin contamination. Trichoderma harzianum is a good biocontrol agent against a wide range of plant pathogens, and previous studies have reported its ability to reduce F. verticillioides colonization under greenhouse conditions. Field trials were conducted in two locations to assess the effect of seed treatment with T. harzianum strain T22 on F. verticillioides kernel colonization and on fumonisin contamination under various natural conditions. An average reduction of 58% in fungal infestation and 53% in mycotoxin contamination was observed during our three-year experiments. This research suggests that seed biopriming with T. harzianum T22 can be a promising and environmentally friendly way to control F. verticillioides kernel colonization and fumonisin accumulation.
Microalgae provide one of the more promising strategies for the production of renewable biodiesel... more Microalgae provide one of the more promising strategies for the production of renewable biodiesel and liquid fuels. Coupling biodiesel production and wastewater treatment based on the use of microalgae can be an effective approach for achieving sustainable production. Several pilot programs aimed at lipid production are currently working with Acutodesmus obliquus, and companies offering algal inocula are increasing in number. A. obliquus strain RL01 was isolated from a pretreated leachate, and preliminary analyses indicated a high growth rate, a final biomass concentration of 1.9 g L -1 and a lipid content of 47% DW. With the aim of strictly differentiating and unequivocally identifying the new strain in comparison with other A. obliquus lipid producers available in culture collections, we employed a DNA barcoding approach, targeting conventional and non-conventional genome regions. Genomic analyses were performed using two internal transcribed spacers (nuclear ITS1 and ITS2 sequences) and three selected chloroplast regions (the trnL genic intron and the rpl20-psbA and psbM-psbZ intergenic spacers). Our findings raise some concerns about the discriminant power of the ITS2 nuclear target and place particular emphasis on the psbM-psbZ plastid DNA barcode, which is characterized by high polymorphism, for use in studies addressing intraspecific genetic diversity.
Fusarium verticillioides is one of the most common plant pathogenic fungi affecting maize causing... more Fusarium verticillioides is one of the most common plant pathogenic fungi affecting maize causing ear and kernel rot. Nearly the totality of the fungal strains are able to produce mycotoxins known as fumonisins at very different levels. However, information on the ability of the biocontrol fungus Trichoderma harzianum to induce systemic resistance in maize against F. verticillioides is still lacking. We now show that, upon root colonization by T. harzianum, F. verticillioides consistently reduces maize disease symptoms. The enhanced activation of SA- and JA/ ET-dependent defence responses indicates that resistance in maize is caused by a better perception of the fungal pathogen due to the effect of Trichoderma inocula. Seed biopriming with T. harzianum could be a useful strategy to control F. verticillioides infection and fumonisin accumulation under field conditions.
Microalgae provide one of the more promising strategies for the production of renewable biodiesel... more Microalgae provide one of the more promising strategies for the production of renewable biodiesel and liquid fuels. Coupling biodiesel production and wastewater treatment based on the use of microalgae can be an effective approach for achieving sustainable production. Several pilot programs aimed at lipid production are currently working with Acutodesmus obliquus, and companies offering algal inocula are increasing in number. A. obliquus strain RL01 was isolated from a pretreated leachate, and preliminary analyses indicated a high growth rate, a final biomass concentration of 1.9 g L -1 and a lipid content of 47% DW. With the aim of strictly differentiating and unequivocally identifying the new strain in comparison with other A. obliquus lipid producers available in culture collections, we employed a DNA barcoding approach, targeting conventional and non-conventional genome regions. Genomic analyses were performed using two internal transcribed spacers (nuclear ITS1 and ITS2 sequences) and three selected chloroplast regions (the trnL genic intron and the rpl20-psbA and psbM-psbZ intergenic spacers). Our findings raise some concerns about the discriminant power of the ITS2 nuclear target and place particular emphasis on the psbM-psbZ plastid DNA barcode, which is characterized by high polymorphism, for use in studies addressing intraspecific genetic diversity.
Journal of agricultural and food chemistry, Jan 20, 2015
The effects of oxidative stress induced by H2O2 were tested in liquid cultures in the fumonisin-p... more The effects of oxidative stress induced by H2O2 were tested in liquid cultures in the fumonisin-producing fungus Fusarium verticillioides. The quantitative analysis of fumonisins B1, B2, B3, and B4 was achieved by means of liquid chromatography coupled to high-resolution mass spectrometry. Two effects in F. verticillioides, consisting of different abilities to produce fumonisins in response to oxidative stress, were identified. Following H2O2 addition, two F. verticillioides strains produced significantly more fumonisin (>300%) while three other strains produced significantly less (<20%) in comparison to control cultures. Transcriptional studies with seven biosynthetic genes showed a significant increase in transcript levels in the strain that made more fumonisin and either no or minimal changes in the strain that made less fumonisin. Our data indicate the important role of oxidative stress toward the modulation of the fumonisin biosynthesis and suggest the necessity to verify...
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Papers by Davide Ferrigo