Fig. 1.

The rgtb1 mutation disturbs flower development and reduces fertility. Selected developmental stages of WT (Col-0, A–F) and rgtb1-2 (G–L) plants. Delay of stamen and vegetative organ growth in comparison with the pistil (G), precocious bud opening, and loss of typical anthesis at stage 13 (H–K). Problems with pollen release (L). (M and N) Ovules in WT (M) and rgtb1+/– (N) flowers around anthesis. (O) Empty ovules of normal size (black arrowheads) or collapsed ovules (white arrowheads) accompany normal mature ovules in rgtb1–/– flowers around anthesis. (P) Number of ovules in mature pistils (from flowers around anthesis). Number of pistils counted: WT n=25, rgtb1-1 n=24, rgtb1-2 n=36. Bars represent the mean ±SEM compared with the unpaired Student t-test. Results are highly significant (P<0.001). (A, G) SEM; (B–F, H–L) stereomicroscopy. Scale bar=1 mm in (B) and (H) which are shown at scale with the photographs in (C–F) and (I–L). Photograph of a cleared pistil under DIC on a microscope (M–O). (This figure is available in color at JXB online.)