Development of an experimental device allowing plant-plant interaction studies and in situ dynamic trapping of volatile organic compounds emitted by barley (Hordeum distichon L.) roots

In response to wounding or herbivore attack, leaves and roots of higher plants release volatile organic compounds (VOCs). To date, VOCs analysis and plant−plant interaction studies have been mainly performed on aboveground plant tissues, leaving the roles played by root VOCs in plant−plant interaction unexplored. In this context, this project aims at setting up an original experimental device allowing both dynamic trapping of VOCs emitted by mechanically damaged H. distichon roots and the study of the roles played by root VOCs in intra and interspecific plant−plant interactions. The experimental device consists of Barley seedlings cultivated in closed PTFE reactors filled with wet sand. Before being analysed by gas chromatography−mass spectrometry, root VOCs are trapped via a dynamic system on Tenax cartridges using a charcoal-filtered and humidified air. Preliminary results show that 7 day-old wounded Barley roots emit C9 fatty acid derivatives (E-non-2-enal and nona-2,6-dienal) as major compounds, contrasting with aboveground plant tissues that mainly emit C6 alcohols, aldehydes, and their derivative esters. For plant−plant interaction studies, receiver plants are exposed to an airflow enriched with VOCs from root damaged Barley plants of the same age.