Development and function of the synergid cell

The synergid cells are located in the female gametophyte and are essential for angiosperm reproduction. During the fertilization process, a pollen tube grows into one of the synergid cells, ceases growth, ruptures, and releases its two sperm cells into this cell. The synergid cells produce an attractant that guides the pollen tube to the female gametophyte and likely contain factors that control arrest of pollen tube growth, pollen tube discharge, and gamete fusion. The synergid cells contain an elaborated cell wall at their micropylar poles, the filiform apparatus that likely plays a role in pollen tube guidance and pollen tube reception. Recent genetic, molecular, and physiological studies in Arabidopsis, maize, and Torenia have provided insights into synergid cell development and the control of pollen tube growth by the synergid cell.