Fig. 1. Morphology of 3-day-old scz root. Scanning electron micrograph of the root at the beginning of the differentiation zone. The tubular outgrowths are root hairs. (A) The alternating files of trichoblasts (t) and atrichoblasts (at) can be seen in the wild-type Landsberg erecta. (B) There are no alternating files of trichoblasts and atrichoblasts in scz mutants. Furthermore, root hairs can be seen originating from the underlying cells (arrows). Bar, 50 µm.