Fig. 3

Relative number of GUS-positive cells in wheat cell suspension cultures bombarded under different DNA/gold coating conditions. a Incubation time (20 min and 3 h, light and dark purple, respectively) for different coating methods. b Sources of ions: 80 mM MgCl₂ or MgAc. P-Ubi:GUS DNA cassette (300 ng per shot) was used for each treatment. The Spd/Ca²⁺ method with 20 min incubation was set as one unit. Bars represent means ± standard errors for three replicates. Different letters above the bars represent significant differences (P < 0.05) using Student’s t-test