Volatile compounds-the language of all kingdoms?

Volatile organic compounds (VOCs) were originally identified as communication compounds between plants and insects. Today, we know that VOCs are released by organisms of all kingdoms, including bacteria and fungi, and mediate diverse intra- and interspecific interactions both above- and below-ground. Following recent trends in this research field, the majority of reviews and research papers in this special issue focus on possible biological and ecological functions and various other aspects of microbial VOCs (mVOCs). Additional reviews and research papers highlight connections between microbe-induced plant VOCs, and their possible application in future sustainable crop protection strategies.