title: Adaptation of Ustilago maydis to extreme pH values: A transcriptomic analysis.
abstract: Fungi are capable to adapt to environments with different pH values. Here we used microarrays to analyze the transcriptomic response of the Basidiomycota Ustilago maydis when transferred from a neutral pH medium to acidic, or alkaline media. Yeast and hyphal monomorphic mutants were used as controls, permitting the identification of 301 genes differentially regulated during the transfer from neutral to an acidic medium, of which 162 were up-regulated and 139 down-regulated. When cells were transferred to an alkaline medium, we identified 797 differentially regulated genes, 335 up-regulated, and 462 down-regulated. The category showing the highest number of regulated genes during the change to either pH, besides "unclassified," was "metabolism," indicating that a very important factor for adaptation is a change in the metabolic machinery. These data reveal that adaptation of U. maydis to environments with different pH involves a severe modification of the transcription machinery to cope with the new conditions, and that the stress by an alkaline environment is more drastic than a change to an acidic medium. The data also revealed that only a minor proportion of the identified genes are under the apparent control of the Pal/Rim pathway, indicating that pH adaptation of this fungus involves other than this cannonical pathway.
authors.affiliation: Departamento de Ingeniería Genética, Unidad Irapuato, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato Gto., México.
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Cervantes-Montelongo
authors.affiliation: Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Biológicas, Laboratorio de Micología y Fitopatología, Unidad de Manipulación Genética, San Nicolás de los Garza, Nuevo León, México.
authors.forename: Elva Teresa
authors.initials: ET
authors.lastname: Aréchiga-Carvajal
authors.affiliation: Departamento de Ingeniería Genética, Unidad Irapuato, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato Gto., México.
authors.forename: José
authors.initials: J
authors.lastname: Ruiz-Herrera
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D015536:Down-Regulation; D005656:Fungal Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D006863:Hydrogen-Ion Concentration; D025301:Hyphae / Q000235:genetics; D053858:Metabolic Networks and Pathways / Q000235:genetics; D059467:Transcriptome; D015854:Up-Regulation; D014588:Ustilago / Q000235:genetics*
chemical_list: D005656:Fungal Proteins
keywords: Gene expression; Microarrays; Transcriptomic analysis; Ustilago maydis; pH adaptation