Figure 4

AtWOX13 gene expression during plant development. (A to L) Expression profile during the initiation and development of lateral roots obtained with 10-day-old AtWOX13::GUS seedlings. Independent lines were tested. (A, C, F and I) GUS staining. (B, D, and K) In situ hybridization with an AtWOX13 antisense probe. (J) In situ hybridization with a GUS antisense probe used as a positive control. (E, H and L) In situ hybridization with a CUC2 antisense probe used as a negative control. (M to S) Expression profile at different plant developmental stages with independent AtWOX13::GUS lines. (M) 5-day-old seedling with staining in the leaf, the hypocotyl, the root vasculature, the pericycle and the primary root tip. (N) Magnification of a 5-day-old seedling primary root tip showing high staining in the stem cell of the proximal meristem. (O) Expression within the shoot apex of 10-day-old seedlings. Note the staining in the leaf primordia. (P to S) Expression within the flower at different developmental stages where staining is seen in the stigmata and the vasculature (P) in the gynoecium (Q) at the floral stage 12–13 where the ovules (Q) are stained. (R) Young embryo, (S) Mature silique. Scale bars = 100 μm except for A, B, R and S (= 50 μm) and M (= 500 μm).