Diversity and functions of fungal VOCs with special reference to the multiple bioactivities of the mushroom alcohol.

Different species of fungi usually share many common pathways but they also have some unique metabolic pathways (e.g. those for specialised metabolites). It is not clear how gene expression patterns significantly contribute to the creation of diverse volatile compounds. Based on the research of most VOCs, the functions of different fungal volatile compounds are mainly as follows: inhibitory or synergistic effects on other microorganisms, promoting growth in plants or inducing a defensive response in crops, and participating in the material cycle or affecting the interactions between organisms in the ecosystem. Approximately three hundred VOCs have been identified from fungi. According to their chemical properties, the major categories of fungal VOCs are terpenoids, aromatic compounds, alcohols, alkanes, esters, aldehydes, ketones, and heterocyclic compounds. The eight-carbon alcohol (1-octen-3-ol) is one of the most characteristic fungal VOC. This abundantly produced VOC results from the breakdown of linoleic acid and causes a distinctive mushroom-like odour. Consequently, its presence has been utilised as a signal of fungal growth. It is also produced by certain plants and functions as a semiochemical for numerous arthropods. The use of