Pollen-pistil interaction is a general term referring to a large number of male (pollen) and female (pistil) interactive events in flowering plants that together lead to seed production. Fertilization depends on growth of the pollen tube within the pistil to deliver sperm, which the pollen tube carries as cargo in its cytoplasm, to the female apparatus, known as the female gametophyte, where the egg cell resides. Upon penetrating the female gametophyte, the pollen tube bursts discharging sperm, enabling fertilization while late-arriving tubes are prevented from entering the already-visited female. The goal of this project is to reveal the mystery behind how these intriguing male-female interactive processes are accomplished. This project takes advantage of the excellent plant model system Arabidopsis, in particular two already characterized mutants defective in the proteins called FERONIA (a Roman goddess of fertility and abundance) [FER] and LORELEI (LRE) (the Germanic mermaid who lured sailors to shipwreck). Loss of these proteins results in multiple pollen tubes being lured into the mutant female, but instead of bursting these pollen tubes continue to grow on a wandering journey inside the female, not discharging their sperm, resulting in a sterile interaction incapable of producing seeds. This project combines molecular genetics, biochemical and cell biological approaches to determine how FER and LRE together generate the female environment capable of mediating a productive male-female encounter. The knowledge obtained will explain a major step used by a plant to produce seeds and will help development of strategies to ascertain preservation and diversification of plant species and ensure production of earth?s major food source, seeds. The project will therefore significantly serve the public?s interests.
Broader impact. By providing training at the doctoral and postdoctoral, this project prepares future leaders in science. Parts of this project are designed to provide research experience to undergraduates, thus broadening the pipeline for future scientists at an early stage. On an even more fundamental level, the project will also create opportunities for hands-on experimentation for high school teachers to extend/renew their classroom and laboratory resources.