Publications by authors named "Claudia Geraldine Leon-Ramirez"

Microbial volatile organic compounds (MVOCs) are mixtures of gas-phase hydrophobic carbon-based molecules produced by microorganisms such as bacteria and fungi. They can act as airborne signals sensed by plants being crucial players in triggering signaling cascades influencing their secondary metabolism, development, and growth. The role of fungal volatile organic compounds (FVOCs) from beneficial or detrimental species to influence the physiology and priming effect of plants has been well studied.

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is a dimorphic fungus used as a model organism to investigate diverse biotechnological and biological processes, such as cell differentiation, heterologous protein production, and bioremediation strategies. However, little is known about the biological processes responsible for cation concentration homeostasis. Metals play pivotal roles in critical biochemical processes, and some are toxic at unbalanced intracellular concentrations.

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Smut fungi comprise a large group of biotrophic phytopathogens infecting important crops, such as wheat and corn. is a plant pathogenic fungus responsible for common smut in maize and teocintle. Through our analysis of the transcriptome of the yeast-to-mycelium dimorphic transition at acid pH, we determined the number of genes encoding chitin deacetylases of the fungus, and observed that the gene encoding one of them (UMAG_11922; ) was the only one up-regulated.

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The life cycle of Ustilago maydis involves alternation of a haploid saprophytic yeast-like stage and a dikaryotic hyphal virulent form. Under in vitro conditions, basidiocarps are formed. Analysis of the transcriptional network of basidiocarp formation revealed the possible involvement of a Tec transcription factor (Tec1, UMAG_02835) in the process.

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The role of the putative homolog of the transcriptional repressor , previously described in , and Cryptococcus neoformans, was analyzed by means of its mutation. In this gene regulates a set of stress-responsive genes, and in it is involved in pathogenesis. It was observed that the gene regulates several aspects of the cell response to acid pH, such as the production of mannosyl-erythritol lipids, inhibition of the expression of the siderophore cluster genes, filamentous growth, virulence and oxidative stress.

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Multicellularity is defined as the developmental process by which unicellular organisms became pluricellular during the evolution of complex organisms on Earth. This process requires the convergence of genetic, ecological, and environmental factors. In fungi, mycelial and pseudomycelium growth, snowflake phenotype (where daughter cells remain attached to their stem cells after mitosis), and fruiting bodies have been described as models of multicellular structures.

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Fungi are considered model organisms for the analysis of important phenomena of eukaryotes. For example, some of them have been described as models to understand the phenomenon of multicellularity acquisition by different unicellular organisms phylogenetically distant. Interestingly, in this work, we describe the multicellular development in the model fungus S.

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We have described that formation of basidiocarps by Ustilago maydis requires illumination. In the current research, we have proceeded to analyze what kind of light receptors are involved in this phenomenon. Accordingly, we investigated whether the homologues of the White Collar (WC), and the phytochrome (PHY) genes played a role in this process.

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Regulation of genes involved in nitrogen metabolism likely plays a role in the ability of fungi to exploit and survive under different environmental situations. To learn about the mechanism of adaptation of the biotrophic fungus Ustilago maydis from a medium containing a source of fixed nitrogen, to a medium depending on the ability to fix N by its bacterial endosymbiont, we explored gene expression profiles using RNA-Seq analyses under these two conditions. The differentially expressed (DE) fungal genes were analyzed, identifying 90 genes that were regulated 24 h after shifting the fungus to media lacking ammonium nitrate as a nitrogen source.

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Trehalose is an important disaccharide that can be found in bacteria, fungi, invertebrates and plants. In some Ascomycota fungal plant pathogens, the role of trehalose was recently studied and shown to be important for conferring protection against several environmental stresses and for virulence. In most of the fungi studied, two enzymes are involved in the synthesis of trehalose: trehalose-6-phosphate synthase (Tps1) and trehalose-6-phosphate phosphatase (Tps2).

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Polyamines are essential metabolites present in all living organisms, and this subject has attracted the attention of researchers worldwide interested in defining their mode of action in the variable cell functions in which they are involved, from growth to development and differentiation. Although the mechanism of polyamine synthesis is almost universal, different biological groups show interesting differences in this aspect that require to be further analyzed. For these studies, fungi represent interesting models because of their characteristics and facility of analysis.

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