Figure 1.

Functional analysis of spermidine (Spd) in response to salt stress in cucumber plants. (A) Increased cucumber salt tolerance by exogenous Spd. Bars: 5 cm. (B) Fresh weight (FW). (C) Dry weight (DW). (D) Electrolyte leakage (EL). (E) The maximum quantum yield of photosystem II (Fv/Fm). (F) The light-saturated rate of CO₂ assimilation (Asat). Cucumber plants were exposed to 75 mM NaCl with or without 1 mM Spd treatment for 7 d, and the phenotype, FW, DW, EL, Fv/Fm, and Asat were measured. All data are presented as the means of 3 biological replicates (± SE). Means with the same letter did not significantly differ at P < 0.05, according to Tukey’s test. Three independent experiments were performed with similar results