Figure 4.

Magnitudes of local burning-induced changes in photosynthetic CO₂ assimilation (A_CO2) (a), non-photochemical quenching of chlorophyll fluorescence (NPQ) (b), and quantum yields of photosystems I (Φ_PSI) (c) and II (Φ_PSII) (d), in the second leaf of pea seedlings under control conditions and after preliminary treatment by sodium orthovanadate (OV) and fusicoccin (FC) (n = 5–6). The preliminary OV (0.5 mM) and FC (1 µM) treatments of the second mature leaves in seedlings were performed by incubation of the leaf (2 h) in solutions of these chemical agents. After that, these leaves were dried by filter paper and used for photosynthetic measurements. OV and FC were dissolved in standard solution (1 mM KCl, 0.5 mM CaCl₂, and 0.1 mM NaCl). Similar incubation in the standard solution was used as the control. The first mature leaf was burned (flame, 2–3 s). *, significant difference between experiment and control plants (p < 0.05).