Vitamin B2 (riboflavin) increases drought tolerance of Agaricus bisporus

authored by

Alexander Guhr, Marcus A. Horn, Alfons R. Weig

Abstract

Drought is a stressor for many soil-inhabiting organisms. Although plants have been extensively investigated for drought-adaptive mechanisms, little information is available for fungi. Antioxidants are especially relevant, since desiccation is accompanied by an excessive intracellular production of reactive oxygen species. Riboflavin (vitamin B

₂) is one antioxidant regulating drought tolerance in plants. A similar function may exist in fungi. Here, we examined the respiratory and transcriptional responses of Agaricus bisporus to drought and the impact of riboflavin. Mesocosm experiments with four groups were established: hyphae were treated with or without 50 μM riboflavin under drought or no drought conditions. Drought increased riboflavin content in hyphae about 5 times with, but also without, addition of riboflavin. Without addition of riboflavin, fungal respiration decreased by more than 50% at water potentials of about −20 MPa. With addition of riboflavin, respiration remained about 2–3 times higher. The transcriptional responses to only drought or only riboflavin strongly overlapped and were mainly based on factors regulating transcription and translation. This was even stronger in combined treatments. Riboflavin induced protective mechanisms in drought-stressed hyphae. Most pronounced was the methylglyoxal (cytotoxic by-product of glycolysis) detoxifying of lactoylglutathione lyase. Thus, our data suggest a stress-priming function and a role of riboflavin in drought responses of A. bisporus.

Organisation(s)

Institute of Microbiology

Type

Article

Journal

MYCOLOGIA

Volume

109

Pages

860-873

No. of pages

ISSN

0027-5514

Publication date

02.11.2017

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Ecology, Evolution, Behavior and Systematics, Physiology, Molecular Biology, Genetics, Cell Biology

Electronic version(s)

https://doi.org/10.1080/00275514.2017.1414544 (Access: Closed)