Figure 2.

The effective quantum yield of PSII photochemistry (Φ_PSII) (a); and the quantum yield of regulated non-photochemical energy loss in PSII (Φ_NPQ) (b); of oregano seedlings grown under optimal conditions (control) or moderate drought stress (MoDS), and sprayed by 1 mM SA or H₂O. Φ_PSII and Φ_NPQ were estimated at 205 (LL) or 1000 (HL) μmol photons m^–2 s^–1. Error bars represent standard deviations (n = 4). Different lowercase letters, within the same light treatment, represent statistical difference (p < 0.05).