After a pollen grain lands on the stigmatic surface of the pistil (female structure of the flower), it forms a pollen tube — a long polar process that transports all of the cellular contents, including the sperm. Pollen tubes invade the pistil and migrate past several different cell types, growing between the walls of the stigma cells, travelling through the extracellular matrix of the transmitting tissue, and finally arriving at the ovary, where they migrate up the funiculus (a stalk that supports the ovule), and enter the micropyle to deliver the two sperm cells–one fertilizes an egg and other the central cell (Figure 1). Typically, only one pollen tube enters the ovule through an opening called the micropyle, terminates its journey within a synergid cell, and bursts to release sperm cells. A pollen tube's journey (Illustration 1) to an egg cell within the pistil therefore involves a series of cell-cell interactions such as attraction, repulsion and adhesion.

What do we do:

"How are pollen tubes precisely guided to their target"– is the question we are trying to solve. Hence, we are focused on identifying and characterizing the guidance signals generated by the A.thaliana pistils to guide pollen tubes to their final target in the embryo sac (Figure 1).

Why do what we do:

Basic Research benefits: Characterization of pollen tube guidance in A. thaliana is important as it focuses on a process that is (i) very unique to plants, (ii) poorly understood at the molecular level and (iii) amenable to genetic, cell biological and biochemical techniques and (iv) a rapid way to identify novel plant signals that allow communication between cells possible despite their thick extracellular walls

Applied benefits: If pollen tube growth and guidance is defective, seeds are not produced. 80% of world's staple food is derived from seeds of crop plants. So studying this process is agriculturally very important. By understanding at the molecular level how seeds are formed we are equipping ourselves with knowledge using which we could (i). improve seed yield, (ii). regulate inter species hybridizations, and there by generate novel plant hybrids and (iii). contain pollen spreading from genetically modified crops–a possibility that will reassure concerened public and regulatory agencies.