Effects of combinational mycelia obtained via in vitro culture on ageing and reproduction in Drosophila melanogaster and their mechanisms

Abstract This research serves to investigate the effects of mycelium combinations obtained by in vitro culture of Amanita virgineoides Bas, Phallus rubicundus (Bosc) Fr., and Lepista nuda (Bull.) Cooke fruiting bodies on ageing and reproduction of Drosophila melanogaster and their underlying mechanisms. The ageing effect was most pronounced in the A. virgineoides + P. rubicundus combination group, with a maximum mortality rate of 18.33% at 6 h. The catalase (CAT) and superoxide dismutase (SOD) activities, as well as the transcripts of the longevity genes Nrf2 and Hep, were significantly downregulated to minima at 9 and 18 h, respectively. The malondialdehyde (MDA) content and transcripts of the signalling pathway-related genes Keap-1, TOR, and S6K as well as the longevity gene MTH were significantly upregulated to maximum levels. This corrected mortality reached 55.49%, with the lowest performance in terms of mean lifespan, maximal mean lifespan, median lethal time and flyability (15.00%) observed in the offspring at 24 h. In the group receiving a combination of A. virgineoides + P. rubicundus + L. nuda, the adult pupae quantity, adult fly quantity, and adult fly rate were the lowest at 14.33%, 4.00%, and 27.63%, respectively. In addition, the adult fly rate reached only 32.32% of that of the control group, and the highest aberration rate (47.78%) was also observed in the offspring. The mycelia of A. virgineoides, P. rubicundus, and L. nuda all demonstrated toxicity against D. melanogaster, and the combinations of different macrofungal mycelia had a synergistic effect regarding their toxicity. The data reported in the present study—particularly when using A. virgineoides and P. rubicundus with potential insecticidal activity against D. melanogaster—are novel. Graphical Abstract