Publications by authors named "Rosa E Cardoza"

Article Synopsis
  • Trichothecenes are toxins from certain fungi that impact plant disease and biological control, and are characterized by a common structure called EPT, with variations in a macrocyclic ring formation.
  • Recent research identified the TRI24 gene as essential for forming this macrocyclic ring in the fungus Paramyrothecium roridum.
  • A mutant strain lacking TRI24 displayed reduced severity in plant disease and antifungal activity, highlighting the significance of the macrocyclic ring in the biological functions of these trichothecenes.
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strains used in vineyards for the control of grapevine trunk diseases (GTDs) present a promising alternative to chemical products. Therefore, the isolation and characterization of new indigenous strains for these purposes is a valuable strategy to favor the adaptation of these strains to the environment, thus improving their efficacy in the field. In this research, a new species, , isolated from vineyards in Ribera de Duero (Spain) area, has been identified and phylogenetically analyzed using 20 housekeeping genes isolated from the genome of 24 species.

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Trichothecenes are a structurally diverse family of toxic secondary metabolites produced by certain species of multiple fungal genera. All trichothecene analogs share a core 12,13-epoxytrichothec-9-ene (EPT) structure but differ in presence, absence and types of substituents attached to various positions of EPT. Formation of some of the structural diversity begins early in the biosynthetic pathway such that some producing species have few trichothecene biosynthetic intermediates in common.

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Native strains of in vineyard soil represent an opportunity for reducing the incidence of grapevine trunk diseases (GTDs) in vineyards. Moreover, its relationship with the environment (physicochemical soil characteristics and farming management practices) remains unclear. In the current study, a survey was carried out on farming management used by viticulturists, and soil samples were studied to analyze their physicochemical properties and to isolate strains.

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Farnesol is an isoprenoid intermediate in the mevalonate (MVA) pathway and is produced by the dephosphorylation of farnesyl diphosphate. Farnesol plays a central role in cell growth and differentiation, controls production of ubiquinone and ergosterol, and participates in the regulation of filamentation and biofilm formation. Despite these important functions, studies of farnesol in filamentous fungi are limited, and information on its effects on antifungal and/or biocontrol activity is scarce.

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The trichothecene toxin-producing fungus has potential as a biological control agent. However, most biocontrol studies have focused only on one strain, IBT 40837. In the current study, three isolates recovered from bean-field soils produced the trichothecene harzianum A (HA) and trichodermol, the latter being an intermediate in the HA biosynthesis.

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The fungus Trichoderma arundinaceum exhibits biological control activity against crop diseases caused by other fungi. Two mechanisms that likely contribute to this activity are upregulation of plant defenses and production of two types of antifungal secondary metabolites: the sesquiterpenoid harzianum A (HA) and the polyketide-derived aspinolides. The goal of the current study was to identify aspinolide biosynthetic genes as part of an effort to understand how these metabolites contribute to the biological control activity of T.

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Trichothecenes are terpenoid toxins produced by species in 10 fungal genera, including species of . The trichothecene biosynthetic gene () cluster typically includes the gene, which encodes a terpene synthase that catalyzes formation of trichodiene, the parent compound of all trichothecenes. The two species, and , that have been examined are unique in that is located outside the cluster in a genomic region that does not include other known genes.

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strains used in biological control products usually exhibit high efficiency in the control of plant diseases. However, their behavior under field conditions is difficult to predict. In addition, the potential of indigenous strains has been poorly assayed as well as their possible behavior as endophytes.

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Trichothecene mycotoxins are recognized as highly bioactive compounds that can be used in the design of new useful bioactive molecules. In , the first specific step in trichothecene biosynthesis is carried out by a terpene cyclase, trichodiene synthase, that catalyzes the conversion of farnesyl diphosphate to trichodiene and is encoded by the gene. Overexpression of resulted in increased levels of trichodermin, a trichothecene-type toxin, which is a valuable tool in preparing new molecules with a trichothecene skeleton.

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Trichoderma biocontrol strains establish a complex network of interactions with plants, in which diverse fungal molecules are involved in the recognition of these fungi as nonpathogenic organisms. These molecules act as microbial-associated molecular patterns that trigger plant responses. Previous studies have reported the importance of ergosterol produced by Trichoderma spp.

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Trichothecenes are sesquiterpene toxins produced by diverse fungi, including some species of Trichoderma that are potential plant disease biocontrol agents. Trichoderma arundinaceum produces the trichothecene harzianum A (HA), which consists of the core trichothecene structure (12,13-epoxytrichothec-9-ene, EPT) with a linear polyketide-derived substituent (octa-2,4,6-trienedioyl) esterified to an oxygen at carbon atom 4. The genes required for biosynthesis of EPT and the eight-carbon polyketide precursor of the octa-2,4,6-trienedioyl substituent, as well as for esterification of the substituent to EPT have been described.

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Trichothecenes are sesquiterpenoid toxins produced by multiple fungi, including plant pathogens, entomopathogens, and saprotrophs. Most of these fungi have the acyltransferase-encoding gene tri18. Even though its function has not been determined, tri18 is predicted to be involved in trichothecene biosynthesis because of its pattern of expression and its location near other trichothecene biosynthetic genes.

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Production of trichothecene toxins occurs in phylogenetically diverse fungi with different lifestyles. In these fungi, most homologs of the trichothecene biosynthetic gene cluster include the transcription factor genes tri6 and tri10. Analyses of phytopathogenic species of Fusarium indicate that the TRI6 and TRI10 proteins positively regulate genes required for synthesis of trichothecenes as well as farnesyl diphosphate (FPP), a precursor of the trichothecene and other terpenoids (e.

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Trichothecenes are terpenoid toxins produced by multiple fungal species with diverse lifestyles. In these fungi, the trichothecene biosynthetic gene (tri) cluster includes a gene encoding a CysHis Zn-finger protein (TRI6). Analyses of plant pathogenic Fusarium species indicate that tri6 regulates tri gene expression.

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Trichothecenes are a family of terpenoid toxins produced by multiple genera of fungi, including plant and insect pathogens. Some trichothecenes produced by the fungus Fusarium are among the mycotoxins of greatest concern to food and feed safety because of their toxicity and frequent occurrence in cereal crops, and trichothecene production contributes to pathogenesis of some Fusarium species on plants. Collectively, fungi produce over 150 trichothecene analogs: i.

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The fungus Trichoderma arundinaceum (Ta37) has a significant biocontrol application which has been related to the production of the trichothecene, harzianum A (2). Previous studies with a strain of T. arundinaceum which was blocked for the production of 2, revealed the existence of a chemical cross-regulation between the biocontrol fungus and its target organism.

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is a filamentous fungus well adapted to different ecological niches. Owing to its ability to antagonize a wide range of plant pathogens, it is used as a biological control agent in agriculture. Selected strains of are also able to increase the tolerance of plants to biotic and abiotic stresses.

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Several spp. are well known for their ability to: (i) act as important biocontrol agents against phytopathogenic fungi; (ii) function as biofertilizers; (iii) increase the tolerance of plants to biotic and abiotic stresses; and (iv) induce plant defense responses via the production and secretion of elicitor molecules. In this study, we analyzed the gene-regulation effects of Epl-1 protein during the interactions of mutant Δ or wild-type strains with: (a) the phytopathogen and (b) with tomato plants, on short (24 h hydroponic cultures) and long periods (4-weeks old plants) after inoculation.

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Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake.

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Trichoderma arundinaceum (Ta37) and Botrytis cinerea (B05.10) produce the sesquiterpenoids harzianum A (HA) and botrydial (BOT), respectively. TaΔTri5, an HA non-producer mutant, produces high levels of the polyketide compounds aspinolides (Asp) B and C.

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Trichoderma harzianum species are well known as biocontrol agents against important fungal phytopathogens. Mycoparasitism is one of the strategies used by this fungus in the biocontrol process. In this work, we analyzed the effect of Epl-1 protein, previously described as plant resistance elicitor, in expression modulation of T.

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Species of Trichoderma exert direct biocontrol activity against soil-borne plant pathogens due to their ability to compete for nutrients and to inhibit or kill their targets through the production of antibiotics and/or hydrolytic enzymes. In addition to these abilities, Trichoderma spp. have beneficial effects for plants, including the stimulation of defenses and the promotion of growth.

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Trichoderma arundinaceum IBT 40837 (Ta37) and Botrytis cinerea produce the sesquiterpenes harzianum A (HA) and botrydial (BOT), respectively, and also the polyketides aspinolides and botcinins (Botcs), respectively. We analysed the role of BOT and Botcs in the Ta37-B. cinerea interaction, including the transcriptomic changes in the genes involved in HA (tri) and ergosterol biosynthesis, as well as changes in the level of HA and squalene-ergosterol.

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Harzianum A (HA), a trichothecene produced by Trichoderma arundinaceum, has recently been described to have antagonistic activity against fungal plant pathogens and to induce plant defence genes. In the present work, we have shown that a tri5 gene-disrupted mutant that lacks HA production overproduces two polyketides, aspinolides B and C, which were not detected in the wild-type strain. Furthermore, four new aspinolides (D-G) were characterized.

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