Figure 7

Fast chlorophyll A Fluorescence Kinetics (OJIP) in Dark-adapted Oat Leaves from the four experimental groups. (A) Quantum yield of PS II determined as Fv/Fm, (B) Performance index (PI), (C) The transient polyphasic curves for each line represent the average of 21 measurements, obtained from three replicates, each contaning seven plants with respective groups. (D) Biophysical parameters of PSII. (E) The energy pipeline leaf model of phenomenological fluxes (per cross-section, CSm) in four groups. The relative changes in arrow witdth depict the value of each parameter. Active Rcs are depicted as open circle, while inactive RCs are represented as closed circle. WW, well-watered oat plants (control); NaCl, oat plants subjected to incremental salinity stress, 50–400 mM NaCl, for 3 weeks; NaCl + SA, oat plants irrigated with 10 mM sodium acetate (SA) mixed with tap water containing varying NaCl concentrations, 50–400 mM, for 3 weeks, and SA, plants irrigated with 10 mM sodium acetate for 3 weeks. Values represent the average ± SE. Different letters indicate significant differences based on one-way ANOVA followed by Tukey's post hoc test at p < 0.001 (n = 21).