Annals of the International Symposium on Fungal Stress – ISFUS

GLYCEROL-3-PHOSPHATE DEHYDROGENASE GFDB IN THE OXIDATIVE STRESS DEFENSE OF ASPERGILLUS NIDULANS

Published in 15/05/2019 - ISBN: 978-85-5722-210-6

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Paper Title
GLYCEROL-3-PHOSPHATE DEHYDROGENASE GFDB IN THE OXIDATIVE STRESS DEFENSE OF ASPERGILLUS NIDULANS
Authors
  • Anita Király
  • Anna Molnár
  • Veronika Bodnár
  • Csaba Hámori
  • Gyöngyi Gyémánt
  • Katalin E. Kövér
  • Éva Leiter
  • István Pócsi
Modality
Abstract
Subject area
Stress mechanisms and responses in fungi: molecular biology, biochemistry, biophysics, and cellular biology
Publishing Date
15/05/2019
Country of Publishing
Brasil
Language of Publishing
Inglês
Paper Page
https://www.even3.com.br/anais/isfus/158589-glycerol-3-phosphate-dehydrogenase-gfdb-in-the-oxidative-stress-defense-of-aspergillus-nidulans
ISBN
978-85-5722-210-6
Keywords
Aspergillus nidulans; oxidative stress; erythritol; mannitol
Summary
Similar to the baker’s yeast Saccharomyces cerevisiae, the genome of the filamentous fungus model organism Aspergillus nidulans also accommodates two genes encoding two isoforms of glycerol-3-phosphate dehydrogenase, which are called GfdA and GfdB. The aim of this study was the phenotypic characterization of the ?gfdB gene deletion strain in A. nidulans. The functional characterization of the gfdA gene was published by Fillinger at al. (2001), and the ?gfdA strain showed a considerable, osmoremediable growth defect, which was indicative of likely disturbances in the biosynthesis of cell wall (Fillinger at l. 2001). The ?gfdB (AN6792) gene deletion mutant was constructed by the Double-Joint PCR method of Yu et al. (2001). The ?gfdB strain also showed somewhat reduced growth on minimal agar medium containing glucose as the sole carbon source [colony diameters: 5.1±0.2 cm (?gfdB) and 6.3±0.2 cm (control), P?0.001, n=3] at 37 °C (incubation time 5 d). Importantly, A. nidulans produced solely erythritol and mannitol sugar alcohols in submerged cultures (Witteveen et al. 1990) as indicated by NMR measurements. The alditols were identified by 1H and 13C NMR spectroscopy, in agreement with literature data. The NMR spectra were recorded at 298 K on Bruker Avance II and Avance NEO spectrometers operating at 500 and 700 MHz 1H frequency, respectively. Meanwhile erythritol production was not disturbed in the ?gfdB strain (273±12 µmol g DCM-1 vs. 251±91 µmol g DCM-1, recorded in the control strain) mannitol was significantly overproduced in the mutant strain even under unstressed culture conditions (632±50 µmol g DCM-1 vs. 429±115 µmol g DCM-1, n=3, P?0.05) as measured by HPLC using a hydrophilic interaction liquid chromatography (HILIC) method for separation. Unexpectedly, the ?gfdB gene deletion strain possessed higher sensitivity to oxidative stress inducing agents like diamide, tert-butyl hydroperoxide (tBOOH) as well as hydrogen-peroxide when compared to the control strain. As oxidative stress response has been associated with secondary metabolite production, we also compared the sterigmatocystin productions of the strains tested, and significant increases in the mycotoxin production have been found in the mutant strain. Significant differences were also observed in the reactive species productions of the strains; it was higher in the ?gfdB strain in comparison to the control either in the presence or in the absence of 0.6 mM tBOOH. Some specific antioxidant enzyme activities, including glutathione peroxidase (GPx), glutathione reductase (GR), catalase and superoxide dismutase (SOD) were also measured in order to gain an overview on the oxidative stress defense systems of the mutant and control strains. The deletion of the gfdB gene increased the specific GR and SOD activities meanwhile the catalase and the GPx activities were lower than those found in the control strain. Moreover, the specific SOD, catalase and GPx activities decreased in the ?gfdB strain under tBOOH stress. The research was financed by the European Union and the European Social Fund EFOP-3.6.1–16–2016-00022, by the National Research, Development and Innovation Office (Hungary) – K112181 and K119494 and by the Higher Education Institutional Excellence Program of the Ministry of Human Capacities of the University of Debrecen.
Title of the Event
III International Symposium on Fungal Stress – ISFUS
City of the Event
São José dos Campos
Title of the Proceedings of the event
Annals of the International Symposium on Fungal Stress – ISFUS
Name of the Publisher
Even3
Means of Dissemination
Meio Digital
DOI
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How to cite

KIRÁLY, Anita et al.. GLYCEROL-3-PHOSPHATE DEHYDROGENASE GFDB IN THE OXIDATIVE STRESS DEFENSE OF ASPERGILLUS NIDULANS.. In: Annals of the International Symposium on Fungal Stress – ISFUS. Anais...São José dos Campos(SP) Hotel Nacional Inn, 2019. Available in: https//www.even3.com.br/anais/ISFUS/158589-GLYCEROL-3-PHOSPHATE-DEHYDROGENASE-GFDB-IN-THE-OXIDATIVE-STRESS-DEFENSE-OF-ASPERGILLUS-NIDULANS. Access in: 18/05/2024

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