Abstract

Most organisms that feed on living meals extract their food stealthily. Chewing insects do this by cutting tissues with sharp mandibles and this minimizes gene expression distal to wounds. However, wound signals escape into distal tissues to initiate the synthesis of the wound hormone jasmonate (JA). How fast is this process and how does it occur? Increases in the level of JA begin in about 30 s within wounds on Arabidopsis leaves and similar increases are seen about 15 s later in distal tissue within the same leaf. It takes about 90 s to detect JA increases in distal leaves. From this it is possible to estimate that long-distance wound signals can travel in the range of 3–8 cm min-1 through a plant. We found that feeding Spodoptera littoralis larvae elicited electrical activity of a similar velocity to the long distance wound signal that leads to JA accumulation distal to wounds. Several clade 3 GLUTAMATE RECEPTOR -LIKE genes that are necessary for the production of these signals were identified. Together with the identification of cellular sites of JA synthesis this is providing new insights into axial and radial wound signalling mechanisms in leaves.