Sperm cells of flowering plants (Angiosperms) are non-motile and are transported via the pollen tube from the stigma to the female gametophyte (embryo sac) to achieve double fertilization. The last phase of the pollen tube path requires extensive cross-talk between both male and female gametophytes. Until recently little was known about the molecules produced by the female gametophyte being involved in this process.

Understanding the molecular mechanisms of the fertilization process in cereals and Arabidopsis thaliana, with a special focus on identifying and characterising key molecules involved in gametophytic pollen tube guidance, is the main goal of our research group. Our hypothesis is that secreted peptides play a major role in these processes. Previously, we have identified the first female gametophyte-derived molecule for micropylar pollen tube attraction (Márton et al. 2005, Science). Moreover, transgenic Arabidopsis ovules expressing the male attractant in the synergid cells of the female gametophyte were capable to guide maize pollen tubes in vitro towards the egg apparatus.

In vivo and in vitro pollen tube (PT) guidance by ZmEA1 signalling in maize.
From Márton and Dresselhaus 2010, Biochem. Soc. Transact.

The main aim now represents the identification and analysis of the attractant-specific receptor at the pollen tube tip surface as well as the associated signal transduction cascades responsible to reorient pollen tube growth direction. In addition, further EA1-box containing proteins including similar proteins in the model plant Arabidopsis will be functionally investigated for their involvement in reproduction and other developmental processes.