Lobster mushroom is a wild edible mushroom with potential commercial value. It is the product resulting of the infection, most commonly of Russula brevipes, by Hypomyces lactifluorum. This study undertook quantitative polymerase chain reaction analysis of tissues sampled at different infection stages to investigate R. brevipes - H. lactifluorum interaction. We followed the colonization of R. brevipes sporocarps by H. lactifluorum that leads to the edible lobster mushrooms. In parallel, metabolomics analysis was performed to detect differences in metabolite profile among non-infected R. brevipes sporocarp and lobster mushroom. The results show that H. lactifluorum DNA is not restricted to the margin but is distributed relatively evenly across the sporocarp of the lobster mushroom. Russula brevipes DNA was also present throughout the sporocarp but was less abundant at the margins and increased inwards. Russula brevipes DNA also declined as the infection progressed. Metabolomics analysis revealed that the flesh of lobster mushroom, which remains identical in appearance to the flesh of the host, undergoes transformation that alters its metabolite profile, most notably of lipids and terpene compounds. These results define a parasitic relationship between the two species that entails a decline of R. brevipes DNA and a modification of its metabolite profile.
Keywords: ADN; DNA; Hypomyces lactiflorum; Hypomyces lactifluorum; Russula brevipes; champignon crabe; lobster mushroom; parasitism; parasitisme.