Oxidative Stress Protection and Glutathione Metabolism in Response to Hydrogen Peroxide and Menadione in Riboflavinogenic Fungus Ashbya gossypii

• Published in: Applied biochemistry and biotechnology 2014-11, Vol.174 (6), p.2307-2325
• Main Authors: Kavitha, S, Chandra, T. S
• Format: Article
• Language: English
• Subjects: Antioxidants - pharmacology; Ashbya gossypii; Biochemistry; Bioinformatics; Biological and medical sciences; Biomass; Biotechnology; catalase; Chemistry; Chemistry and Materials Science; Dose-Response Relationship, Drug; Eremothecium - cytology; Eremothecium - drug effects; Eremothecium - genetics; Eremothecium - metabolism; Eremothecium gossypii; Extracellular Space - drug effects; Extracellular Space - metabolism; Fundamental and applied biological sciences. Psychology; Fungi; Gene Expression Regulation - drug effects; genes; glutathione; Glutathione - metabolism; glutathione peroxidase; glutathione-disulfide reductase; Hydrogen peroxide; Hydrogen Peroxide - pharmacology; menadione; messenger RNA; Metabolism; Oxidative stress; Oxidative Stress - drug effects; Oxidative Stress - genetics; response elements; Response Elements - drug effects; reverse transcriptase polymerase chain reaction; riboflavin; Riboflavin - biosynthesis; stress response; superoxide dismutase; Time Factors; transcription (genetics); Transcription Factors - metabolism; Vitamin K 3 - pharmacology
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-014-1188-4

Ashbya gossypii is a plant pathogen and a natural overproducer of riboflavin and is used for industrial riboflavin production. A few literature reports depict a link between riboflavin overproduction and stress in this fungus. However, the stress protection mechanisms and glutathione metabolism are not much explored in A. gossypii. In the present study, an increase in the activity of catalase and superoxide dismutase was observed in response to hydrogen peroxide and menadione. The lipid peroxide and membrane lipid peroxide levels were increased by H₂O₂ and menadione, indicating oxidative damage. The glutathione metabolism was altered with a significant increase in oxidized glutathione (GSSG), glutathione peroxidase (GPX), glutathione S transferase (GST), and glutathione reductase (GR) and a decrease in reduced glutathione (GSH) levels in the presence of H₂O₂ and menadione. Expression of the genes involved in stress mechanism was analyzed in response to the stressors by semiquantitative RT-PCR. The messenger RNA (mRNA) levels of CTT1, SOD1, GSH1, YAP1, and RIB3 were increased by H₂O₂ and menadione, indicating the effect of stress at the transcriptional level. A preliminary bioinformatics study for the presence of stress response elements (STRE)/Yap response elements (YRE) depicted that the glutathione metabolic genes, stress genes, and the RIB genes hosted either STRE/YRE, which may enable induction of these genes during stress.