2.3. Concentration of Phytohormones, Amino Acids and Phytoprostanes in Leaves Several phytohormones were identified in leaves in both species at the 15th day after imposing treatments: the precursor of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), cytokinins (TZ, TZ-rib and TZ-glc), abscisic acid (ABA), salicylic acid (SA) and the phytoalexin scopoletin (SC) (Table 3).