The Ustilago maydis null mutant strains of the RNA-binding protein UmRrm75 accumulate hydrogen peroxide and melanin

• Published in: Scientific reports 2019-07, Vol.9 (1), p.10813-13, Article 10813
• Main Authors: Rodríguez-Piña, Alma Laura, Juárez-Montiel, Margarita, Hernández-Sánchez, Itzell Eurídice, Rodríguez-Hernández, Aída Araceli, Bautista, Elihú, Becerra-Flora, Alicia, López-Villegas, Edgar Oliver, Jiménez-Bremont, Juan Francisco
• Format: Article
• Language: English
• Subjects: 101/58; 101/6; 14; 14/34; 14/63; 38/77; 631/326/193/2484; 631/337/572; Catalase; E coli; Fungal Proteins - genetics; Fungal Proteins - metabolism; Fungi; Gene deletion; Gene expression; Gene Expression Regulation, Fungal; Humanities and Social Sciences; Hydrogen peroxide; Hydrogen Peroxide - metabolism; Melanin; Melanins - metabolism; Morphogenesis; multidisciplinary; Mutants; Mutation; Organisms, Genetically Modified; Pathogenicity; Pathogens; Peroxisomes; Ribonucleic acid; RNA; RNA-binding protein; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Science; Science (multidisciplinary); Strains (organisms); Transcription termination; Ustilago - genetics; Ustilago - metabolism; Ustilago maydis
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-47133-4

Ustilago maydis is a dimorphic fungus that has emerged as a model organism for the study of fungal phytopathogenicity and RNA biology. In a previous study, we isolated the U . maydis UmRrm75 gene. The deletion of the UmRrm75 gene affected morphogenesis and pathogenicity. UmRrm75 gene encodes a protein containing three RNA recognition motifs. Here we determined that UmRrm75 has chaperone activity in Escherichia coli using the transcription anti-termination assay. Subsequently, we analyzed the growth of Δ UmRrm75 mutants at 15 °C and 37 °C, observing that mutant strains had reduced growth in comparison to parental strains. UmRrm75 gene expression was induced under these non-optimal temperatures. Δ UmRrm75 mutant colonies displayed a dark-brown color at 28 °C, which was confirmed to be melanin based on spectroscopic analysis and spectrometric data. Furthermore, Δ UmRrm75 mutant strains showed the presence of peroxisomes, and increased H 2 O 2 levels, even at 28 °C. The Δ UmRrm75 mutant strains displayed a higher expression of redox-sensor UmYap1 gene and increased catalase activity than the parental strains. Our data show that deletion of the UmRrm75 gene results in higher levels of H 2 O 2 , increased melanin content, and abiotic stress sensitivity.