Oxidized Fatty Acids as Inter-Kingdom Signaling Molecules

Abstract: Oxylipins or oxidized fatty acids are a group of molecules found to play a role in signaling in many different cell types. These fatty acid derivatives have ancient evolutionary origins as signaling molecules and are ideal candidates for inter-kingdom communication. This review discusses examples of the ability of organisms from different kingdoms to “listen” and respond to oxylipin signals during interactions. The interactions that will be looked at are signaling between animals and plants; between animals and fungi; between animals and bacteria and between plants and fungi. This will aid in understanding these interactions, which often have implications in ecology, agriculture as well as human and animal health. Keywords: oxidized fatty acids; signaling; inter-kingdom communication 1. Introduction Until recently the study of signaling and response in different kingdoms of life developed independently from each other, with little regard for the similarities between the different kingdoms. However, it has become apparent that elements of signaling are shared by different kingdoms [1–4]. It is speculated that many of these are ancestral traits or that some may be due to convergent evolution, horizontal gene transfer or ancient symbiosis [1]. These shared signals come into play when there is interaction between members of the different kingdoms (ranging from mutually beneficial interactions such as symbiosis, to ones harmful to at least one member such as parasitism), and include plant defenses against herbivores and plant pathogens, animal defenses against pathogenic microbes and