Systemic activation of p46 and p44 MAPKs by nonanoic acid in L. temulentum . The herbicides were painted directly onto the leaves of three-to-four-week-old plants using a soft bristle brush. The control plants were treated with a solution of 0.1% tween 20. RdUp+: "Roundup Weed and Grass Killer - Ready to use plus" was used directly from the bottle (2% NNA and related fatty acids); Scythe: "Scythe Herbicide concentrate" diluted 1 to 25 mL in 0.1% tween 20 (final concentration of 2% NNA and related fatty acids). Nonanoic acid (NNA) was diluted to 2% by diluting it 1 to 50 mL in 0.1% tween 20. One plant per time point was collected at the times indicated above for each treatment described, the tissues from the treated tiller and systemic tiller (SYS) were collected and processed separately. To determine MAPK activity, immunoblots of protein extracts were performed using anti-phospho-MAPK (Erk1/2) antibody. The experiments were independently repeated a minimum of three times. Representative blots are presented.