Figure 1.

CSI1 Deficiency Results in Defective Anther Dehiscence and Complete Sterility.

(A) Expression of CSI1 in floral tissues at floral stages 11 to 14 (1) to (4). CSI1 is highly expressed in stigma and pollen grains (6) and modestly in sepals (5).

(B) Six-week-old csi1-2 plants are completely sterile. Siliques of wild-type (WT) and csi1-2 plants are indicated with arrows.

(C) Mature but shorter silique developed from a csi1-5 pistil manually pollinated with wild-type pollen (right) compared with a wild-type silique (left).

(D) Developmental series of wild-type flowers during anther stages 12 to 14 (defined according to Sanders et al. [1999]). Intact flowers from a single inflorescence (Top) and the same flower with sepals and petals removed (Bottom) are shown. Anthers dehisced at anther stage 13 (highlighted and magnified in rectangle).

(E) Comparison of the csi1-2 flowers to wild-type ones at the same stages as shown in (D). Anther dehiscence did not occur until anther stage 14 (highlighted and magnified in rectangle).

Bars in (A) (1) and (5) = 1 mm, (2) to (4) = 0.5 mm, and (6) = 5 μm; bars in (B) and (C) = 0.5 cm; bars in (D) = 0.2 mm; bars in (E) = 0.25 mm.