Prevention of senescence in the ascomycete Podospora anserina by the antibiotic tiamulin

Abstract

THE syndrome of senescence or aging is common to all living material. In many fungi the peripheral hyphae become senescent after prolonged vegetative growth, that is, their growth rate decreases and they eventually die. In some fungi, senescence is caused by transmissible elements, of temporarily if their metabolism is drastically reduced^1,5, but anastomosis. The onset of senescence is influenced by environmental as well as genetical factors^1–6. In Podospora anserina, where senescence has been very thoroughly analysed, it was shown that senescent mycelia may recover temporarily if their metabolism is drastically reduced^1,5, the mycelia soon become senescent when grown in normal conditions. The nature of the senescent agent in Podospora is obscure. All efforts to demonstrate viruses or virus-like particles in aging hyphae of Podospora have failed (R. Bozarth, personal communication). Our endeavours to determine the nature and action of the senescent agent were encouraged by previous findings that the onset of senescence can be completely prevented by a synergistic action of specific genes⁶. In this paper we show that an antibiotic, tiamulin, can mimic the effect of these genes.