Mycoviruses Infecting True Truffles

The study of viruses able to infect fungi (mycoviruses) is a relative new branch of virology that is expected to increase drastically in the next future due to the next generation sequencing technologies contribution. Mycoviruses are often latent or symptomless in many fungi but can also cause various effects on the hosts such as hypovirulence, lack of sporulation but also hypervirulence. Several viral agents have identified as the etiologic agents of economically important diseases of the mushrooms Agaricus bisporus and Pleurotus ostreatus, while many others have been isolated from asymptomatic edible fungi. In the last years few reports confirmed that mycoviruses also infect both arbuscular or ectomycorrhizal fungi such as Rhizophagus clarus, Hebeloma circinans or Pisolithus microcarpus. Up to now just several viruses have been reported infecting the true truffles Tuber aestivum and Tuber excavatum apparently not associated to alterations on morphology of the colonized fruiting bodies or mycelia. We recently obtained evidences that new viral species within the genus Endornavirus infect symptomatic fruiting bodies of Tuber magnatum. Considering the lack of information about mycoviruses infecting the genus Tuber and the devastating effect of some viral diseases of mushrooms, we should not underestimate the potential risk of viral infection in truffles. We therefore need to improve knowledge regarding the viral population of true truffle worldwide, in particular considering the high economic impact of this crop