The (Not so) Secret Sex Life of Plants

Fertilization in plants is unique because it involves two pairs of sperm and egg cells, a process known as double fertilization. One pair will join to produce the embryo and the other pair will fuse in the ovary to produce the nutrient-rich endosperm. Double fertilization is important for fertility and seed production in flowering plants. An increased understanding of the process will provide tools for crop improvement and breeding programs.

Scientists from the University of Leicester in the United Kingdom and Pohang University of Science and Technology in South Korea discovered a gene that plays a linchpin role in allowing precursor reproductive cells to divide to form twin sperm cells. Details of their study appear in this week’s issue of Nature.

The gene FBL17 was found to be capable of triggering the destruction of the protein inhibitors KRP6 and KRP7. These proteins suppress the activity of cyclin-dependent kinase A1, a factor necessary for cell division. Plants with a mutated version of FBL17 produce pollen grains with a single sperm cell instead of the pair of sperm that are required for successful double fertilization. David Twell, co-author of the paper, noted that this discovery will be useful in understanding the evolutionary origins of flowering plant reproduction and may be used by plant breeders to control crossing behavior in crop plants.

For more information, visit http://www2.le.ac.uk/ebulletin/news/press-releases/2000-2009/2008/10/nparticle.2008-10-20.2007379639 The abstract of the paper is available at http://www.nature.com/nature/journal/v455/n7216/abs/nature07289.html