Fig. 2

Effect of NaHS on the pH of the root bathing solution (a and b), ferric-chelate reductase (FCR) activity (c and d), and root apoplast Fe content (e and f) of iron-deficient Glycine max plants. The 3-w-old G. max seedlings were treated with the nutrition solution containing 1 μM Fe(III)-EDTA or 50 μM Fe(III)-EDTA with or without 100 μM NaHS for 15 d. A and B show the pH of the root bathing solution of the –Fe or + Fe plants, respectively. C and D show ferric-chelate reductase (FCR) activity of the –Fe or + Fe plants, respectively. E and F show the root apoplast Fe content of the –Fe or + Fe plants, respectively. Error bars represents the mean ± SE. * indicates a significant difference at P < 0.05. –Fe, 1 μM Fe; −Fe + NaHS, seedlings treated with 100 μM NaHS and 1 μM Fe; +Fe, 50 μM Fe; +Fe + NaHS, seedlings treated with 100 μM NaHS and 50 μM Fe