Pollination involves an interaction between the female tissues (stigma, sty
le and ovary) and the male gametophyte or the pollen tube cell, which conta
ins the sperm cells. Freezing methods now allow us to visualize the extrace
llular matrices that guide pollen tubes to the ovary, Adhesion of the polle
n tube to these specialized extracellular matrices might be a mechanism of
guidance and tube cell movement in the style. In lily, the stylar adhesion
molecules are a pectin and a small, basic cysteine-rich protein, both of wh
ich are necessary to induce tube cell adhesion to an artificial, in vitro s
tyle matrix.