ADHESION OF LILY POLLEN TUBES ON AN ARTIFICIAL MATRIX

We proposed that pollination in lily is a case of cell adhesion and ce ll movement, but experimental evidence for the adhesion event is lacki ng. In this study, we developed an artificial extracellular matrix tha t mimics the in vivo lily stylar transmitting tract. This artificial m atrix was created by applying the transmitting tract exudate extracted from lily styles onto a nitrocellulose membrane. When in vitro-grown pollen tubes were applied to the matrix, they adhered by their tips to the area of the stylar exudate which is rich in arabinogalactan prote ins. Once they adhered, they grew on the in vitro artificial matrix at rates faster than normal. This is the first experimental evidence dem onstrating the adhesion of in vitro-grown pollen tubes, an event that has been described as common in vivo. The adhesion event is stylar exu date specific, concentration dependent, and is affected by the develop mental age of the pollen tube. This bioassay for pollen tube adhesion will be used to isolate the adhesive molecules from the stylar exudate .