Fig. 5.

Ascorbate peroxidase (APX; A), glutathione reductase (GR; B), superoxide dismutase (SOD; C), and catalase (CAT; D) activities in randomly selected, fully expanded penultimate leaves of Spartina densiflora in response to teatment with 0 mmol l⁻¹ and 1 mmol l⁻¹ Zn at 0, 1, and 3% NaCl over 90 d. Values represent the mean ±SE, n=4–6. Different letters indicate means that are significantly different from each other (two-way ANOVA, Zn×salinity; LSD test, P <0.05). Zn, NaCl, or Zn×NaCl in the corner of the panels indicate when the main effects and interaction term are significant.