Sclareolide

Stock solutions (100 mM) of sclareol (Sigma) and sclareolide (Sigma) in methanol and a stock solution (100 mM) of ACC (Sigma) in water were diluted in water to various concentrations. Methanol concentrations did not exceed 0.1% in all the experiments.
Roots of plants grown in the sand system were treated by soaking the pot itself in a solution containing various concentrations of each chemical in a tray, with their roots submerged in the solution. After soaking for 24, 48, or 72 h, the treated plants were transferred to a new tray containing water and used for RKN penetration assays; or the roots were pulled out of the pots, washed with water, and used for real-time RT-PCR analysis or quantification of thioglycolic acid lignin.
For treatment of the roots of hydroponically grown plants, plants were pulled out of the fertilizer, transferred to a petri dish containing water with their roots submerged in the water, and preincubated for 48 h to diminish the influence of any wound stresses that could be caused by removal. After discarding water using a pipette, the plant roots were treated by gently adding a solution containing various concentrations of each chemical to the petri dish until the roots were submerged in the solution, incubated for adequate time periods, and used for phytohormone measurements, immune complex kinase assays, or histochemical analysis of lignin.