Fig. 1.

AtGRF proteins show transactivation activity in the yeast GAL4 system. DNA fragments encoding the depicted portions of GRF1 (1F-1ΔF), GRF2 (2F-2ΔF), and GRF5 (5C) were fused to the DNA sequence encoding GAL4-DBD and introduced into yeast cells. Two independent transformants for each fusion construct were tested for their ability to activate the expression of the HIS3 and LacZ reporter genes. -Trp and -His/Trp denote the colonies grown on plates lacking Trp and His/Trp, respectively; LacZ denotes β-galactosidase activities on filters after a colony-lift assay.