Fig. 3

Effects of different concentrations of hemin (0, 100, 500, 1000, and 2000 µM) on root length (a) and plant height (b) of tomato seedlings under drought stress. Photographs (c) showed the tomato seedlings were incubated in the mixture of Hoagland solution and 5% PEG containing different concentrations of hemin for 7 days. The data are the average of three replicates and are presented as means ± SE. Different letters indicate significant differences at P < 0.05 according to Duncan’s multiple range tests