ZjPCKpro:ZmSHR1 transgenic seedlings develop longer roots than the wild type. A to D, Two-week-old wild-type (A and B) and ZjPCKpro:ZmSHR1 (C and D) plants grown on one-half-strength Murashige and Skoog plates, with magnified images of detached wild-type (B) and ZjPCKpro:ZmSHR1 (D) roots. Red arrows indicate fine lateral roots, and red arrowheads point to elongated root tips. E to J, Transverse sections through the root apex (E and F), elongation zone (G and H), and maturation zone (I and J) of 2-week-old wild-type (E, G, and I) and ZjPCKpro:ZmSHR1 (F, H, and J) roots. Bars = 1 cm (B and D) and 50 µm (E–J).