What is the function of the synergids?

In plant biology, the synergids are specialized cells found in the female gametophyte, specifically within the ovule of a flowering plant. The function of synergids is primarily related to sexual reproduction and facilitating the fertilization process.

During plant reproduction, the synergids are located adjacent to the egg cell or oosphere, which is one of the two female gametes. The other female gamete is the central cell, which contains the two polar nuclei. The synergids play a crucial role in guiding and interacting with the pollen tube during fertilization.

The main functions of the synergids are as follows:

Attraction and guidance: The synergids release chemical signals known as attractants that help guide the pollen tube toward the ovule. These attractants, such as peptides and small molecules, are perceived by the growing pollen tube, enabling it to navigate towards the embryo sac, which contains the synergids and the egg cell.

Interaction with the pollen tube: As the pollen tube approaches the synergids, it forms a close association with them. This interaction involves physical contact and the exchange of molecular signals. The synergids provide guidance and nourishment to the pollen tube, facilitating its growth and ensuring its proper direction towards the egg cell.

Degeneration: Once the pollen tube successfully reaches the synergids, one of the synergids usually degenerates, allowing the other to remain intact and interact with the pollen tube and the male gametes. This degeneration process is known as synergid degeneration.

Reproductive barrier: The synergids also play a role in preventing multiple pollen tubes from entering the ovule. Once a pollen tube reaches a synergid, it releases molecules that induce the degeneration of other competing pollen tubes, ensuring that only one pollen tube reaches the egg cell for fertilization.

Overall, the synergids serve as essential components of the female reproductive system in flowering plants. Through their attractive signals, guidance, and interactions with the pollen tube, they contribute to the successful fertilization of the egg cell, leading to the formation of seeds.