In a landmark discovery, scientists at the University of California, Davis, have found that a hormone called auxin is responsible for egg productioninplants.

It is the first definitive study of a plant hormone acting as a morphogen-a substance that directs the pattern of development of cells based on its concentration.

In addition, the results provide tantalizing new insights into the evolutionary pathway that flowering plants took 135 million years ago when they split off from gym-nosperms-the "naked-seeded” plant group that includes conifers, cycads and ginkgo trees. The researchers also used their discovery to make additional egg cells within plant reproductive structures, raising the prospects that these techniques might someday be used for enhancing the reproduction and fertility of crop plants.