Pollen tube attractant found

A molecule that guides the growing pollen tube towards the embryo sac of flowering plants has finally been discovered. The so called LURE proteins are defensin-like and cysteine-rich polypeptides secreted by the two synergid cells surrounding the egg. The LURE proteins were abundantly expressed in the synergid cells and showed marked pollen tube attractive effect in vitro. When expression of the LURE proteins was inhibited by injection of morpholino antisense oligomers, attraction of the pollen tube was impaired. Tetsuya Higashiyama and colleagues from Nagoya University in Japan made their discovery in the unique protruding embryo sac of the wishbone flower (Torenia fournieri).

Source: Okuda et al. (19 March 2009) Nature 458: 357-361