Plant Sex Requires D-Serine

After pollen lands on a flower, its sperm don’t have the ability to swim to a plant’s ovules. So fertilization instead requires the pollen cells to grow as long as 12 inches so the sperm can reach their ovule target. Now, researchers led by José A. Feijó, a plant scientist at the University of Lisbon, in Portugal, report that D-Serine is involved in the signaling pathways that direct the pollen tube cells to their objective (Science, DOI: 10.1126/science.1201101). D-Serine regulates a calcium ion channel that is found in high density in the pollen tube cell. It is essential for the pollen tube cell’s rapid growth, which delivers the sperm to the ovules located at the bottom of a plant’s pistil. “D-Serine is a novel signaling mechanism in plants,” comments Jose Gutierrez-Marcos, a plant researcher at the University of Warwick, in England. “What is quite exciting is that this D-Serine signaling is quite similar to what is observed in animal neurons,” he adds, where D-Serine also activates ion channels.