Mechanisms behind interplant communication - "How do plants talk?"

Abstract

When plants are under herbivore or pathogen attack, or experiencing abiotic stress conditions, they can emit signalling molecules that can be received and perceived by their neighbouring plants. Receiving plants can respond to such signals by inducing defence responses, changing growth or priming their defences for possible future attack. Such transfer of information between plants, also named ‘interplant communication’, can take place above or below ground. Above ground signalling molecules are transported through air as blends of volatile compounds of specific concentrations. Below ground, plants can send and perceive signals through roots or common mycorrhizal networks. Numerous studies performed over the last three decades brought better understanding of the identity of signaling molecules and mechanisms behind the emission and perception of them. However there is still a lack of information, especially on the molecular mechanisms of signalling pathways involved in the signal emission, perception and processing. Furthermore, most of the published studies have so far focused on the specific types of signalling taking place either above or below ground, considering plant tissues as independent systems. This thesis presents review of all currently known mechanisms of interplant communication, the circumstances under which these mecahnsims are triggered and the signal molecules that are involved. Different mechanisms of interplant communication are discussed in integrated manner, taking into account plants as whole organisms that are able to perceive and simultanesously respond to several stimuli.