Fig. 5.

anx1 anx2 pollen germinate normally on stigma but produce pollen tubes that fail to reach the female gametophytes. (A) Aniline Blue staining of wild-type pistils pollinated with a few anx2-1 single-mutant (left) or anx1-1/anx1-1 anx2-1/ANX2 double-mutant (right) pollen grains. Eighteen hours after pollination, most of the tips of anx2-1 PTs (left) were observed in the ovary locules (rectangle). By contrast, only about half of the tips of germinated (arrows) anx1-1/anx1-1 anx2-1/ANX2 PTs (arrowheads) were found in the ovary locules. (B) Aniline Blue staining of wild-type pistils pollinated with numerous wild-type (left) or anx1-2 anx2-2 double-homozygous mutant (right) pollen grains. Eighteen hours after manual pollination, wild-type PTs (left) had grown through the entire pistil to reach the micropyles of the ovules (asterisks). Although they germinated on the stigma, most of the anx1-2 anx2-2 mutant PTs (right) were arrested in the style, with only very few having reached the top end of the ovary (arrows). The boxed regions are shown at high magnification below and reveal the very low density of anx1-2 anx2-2 PTs (right) in the transition zone between the style and the ovary locules in comparison to wild-type PTs (left). Scale bars: 100 μm in A and in top row in B; 25 μm in bottom row in B.