Interactions of HvWRKY38, BPBF, SAD, and HvGAMYB in regulating the expression of the Amy32b promoter. A, Schematic diagram of the reporter and effector constructs used in the cobombardment experiment. B, The reporter construct, Amy32b-GUS, and the internal construct, UBI-Luciferase, were cobombarded into barley aleurone cells either with (+) or without (−) the effector construct using the same molar amount of effector and reporter constructs. GUS activity was normalized in every independent transformation relative to the luciferase activity. Bars indicate GUS activities ± se after 24 h of incubation of the bombarded aleurone cells with (+) or without (−) 1 μm GA. Data are means ± se of four replicates.