The Influence of Pine Volatiles on the Growth of an Ophiostomatoid Fungi Associated with Pine Wilt Disease in Pinus pinaster  ^†

Phytopathogenic ophiostomatoid fungi play an important role in pine wilt disease (PWD), caused by the pinewood nematode (PWN), since they begin proliferating once the pine hosts decay and can serve as a food source for the PWN. In a recent study, the ophiostomatoid fungi that are associated with naturally infected Pinus pinaster were profiled and cultured. To understand the influence of volatiles that are commonly emitted by pines on fungal growth, the present work aimed at analyzing the influence of α-pinene, β-pinene and trans-β-caryophyllene on a Leptographium isolate. The volatiles promoted fungal growth in the first 24 h, but lost their effect after 48 or 72 h, probably due to compound volatilization. After 5 days, the fungal growth was comparable to that of control cultures, except for α-pinene, which appeared to slightly inhibit fungal growth. Profiling the influence of volatile organic compounds on the PWD complex can contribute to a better understanding of the chemical communication that is occurring between its different intervenients.