Exposure to green leaf volatiles activated p46 and p44 MAPKs in L. temulentum. (A) Three-week-old plants at the one tiller stage were placed into a closed clear (non-air tight) cylinder with freshly mowed grass clippings (see illustration). Control plants were placed into the cylinders without any grass clippings present. (B) One plant per time point was collected at the times indicated. To determine MAPK activity, immunoblots of protein extracts were performed using anti-phospho-MAPK (Erk1/2) antibody. The experiments were independently repeated three times. Representative blots are presented.