Figure 2.
Root hairs observed by DICM. Roots of 4-d-old seedlings were used for the analysis. A through C, Root hair development in wild-type plants. A and B, An initial bulge is formed at the distal end of the trichoblast. C, The root hair develops by tip growth. D through F, Root hair phenotype of der1-1 mutant. D, Root hairs often show an irregular diameter. E, The lower part of the root hair is enlarged (left) or only an enlarged, short root hair forms (right). F, Two root hairs initiate from the bulge, indicating uncontrolled initiation of tip growth on the bulge. G through I, Root hair phenotype in der1-2 and der1-3 plants. G, Root hairs are very short and have an irregular diameter. H, The root hair basis is frequently enlarged. I, The initial bulge extends over a large part of the epidermal cell and two root hairs appear to develop. Arrows in C and D indicate the distal end of the trichoblast cell. Bar = 40 μm.