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

Alma Laura Rodríguez-Piña, Margarita Juárez-Montiel, Itzell Eurídice Hernández-Sánchez, Aída Araceli Rodríguez-Hernández, Elihú Bautista, Alicia Becerra-Flora, Edgar Oliver López-Villegas, Juan Francisco Jiménez-Bremont*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


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 ΔUmRrm75 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. ΔUmRrm75 mutant colonies displayed a dark-brown color at 28 °C, which was confirmed to be melanin based on spectroscopic analysis and spectrometric data. Furthermore, ΔUmRrm75 mutant strains showed the presence of peroxisomes, and increased H2O2 levels, even at 28 °C. The ΔUmRrm75 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 H2O2, increased melanin content, and abiotic stress sensitivity.

Original languageEnglish (US)
Article number10813
JournalScientific Reports
Issue number1
StatePublished - Dec 1 2019

Bibliographical note

Funding Information:
This work was supported by CONACYT (Proyectos de Desarrollo Científico para atender Problemas Nacionales 2015, 2015-01-414) funding. The authors thank to Dr. Maria Azucena Ortega Amaro, Dr. Araceli Patrón Soberano and Ms. Guillermo Vidriales Escobar from IPICYT for technical assistance, and Ying Sun and Steffen Graether for grammatical review.

Publisher Copyright:
© 2019, The Author(s).

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