Fig. 2

Plant volatile compounds activated the Lt 46 and 44 kDa MAPKs. a A list of 13 plant volatile compounds separated into different chemical groups (alcohols, aldehydes and ketones) that were tested for their ability to activate the Lt 46 and 44 kDa MAPKs. Chemical name (company, catalog number). b Representative immunoblots of MAPK activation for one member of each chemical class of compounds are presented. Plants were exposed to vapors of each individual volatile compound by pipetting 10 µL of the compound onto a Q-tip in the cylinder, and then 3–4 week-old Lt plants at the two tiller stage were placed into a closed clear (non-air tight) cylinder. One plant per time point was removed from the cylinder and collected at the times indicated. Note control treatment plants were placed into the cylinders without addition of a volatile compound—see Fig. 1. To determine MAPK activity, immunoblots of protein extracts were performed using anti-phospho-MAPK (Erk1/2) antibody. The experiments were independently repeated three times per compound