Fig. 6. Ectopic expression of PFS2 affected organ differentiation. The 35S cauliflower mosaic virus promoter drove PFS2 expression in these transgenic plants. (A) In plants with the highest level of expression, had defects in differentiation of leaf primordia. This four-week-old plant had an enlarged apical meristem (am), but lacked leaf primordia. (B) In a few plants, leaf primordia (lp) emerged, but none of these developed into a mature leaf (l). (C) Other transformants exhibited altered phyllotaxy and reduced leaf development as the plant aged. (D) In plants with lower levels of PFS2 expression, flowers formed. However, these flowers sometimes had carpelloid stamens (cs) with stigmatic papillae (sp) on the tips. (E) In other flowers, the petals were highly reduced in size and carpelloid stamens arose between the second and third floral whorls. (F) In ovules, the outer integument frequently did not undergo asymmetric cell expansion, which is characteristic of wild-type ovules. (G) In the nucellus (n) of these plants, the MMC was absent. In its place were small parenchymatous cells. (H) Relative PFS2 transcript levels were measured using RT-PCR in wild-type flowers (wt) and flowers overexpressing PFS2 (OE). ACTIN11 (ACT11) transcript abundances were used as controls. Scale bars: 20 µm in F,G; 50 µm in D,E. a, anther; c, cotyledon; et, endothelium; f, funiculus; ii, inner integument; oi, outer integument; p, petal; pi, pistil; s, sepals; st, stamens.