Figure 4
From: Physiological responses to humic substances as plant growth promoter
Visualization of β-glucoronidase (GUS) activity in the root of DR5:GUS transgenic tomato. Seedlings were grown for 4 days in a 2-mM CaCl2 medium and then incubated for 4 days in water (A), 10−6 M indole acetic acid (B) and 2.5 mM C of humic substances isolated from cattle manure vermicompost after free lipid removal (C) (Adapted from Canellas et al. [22]).