DURHAM, N.C. – What do frog eggs have in common with anti-aging creams? Their success depends on a group of chemical compounds called retinoids, which are capable of generating and re-generating tissues.

A new study in plants shows that retinoids’ tissue-generating capacities are also responsible for the appropriate development of roots.

If you’ve ever planted a radish seed, you know that the first thing it does is develop a long vertical root. Give it a bit more time, and it will get smaller roots that run perpendicular to the plant’s stem. Over time, these lateral roots will branch repeatedly and spread out, forming a web that stabilizes and feeds the plant.

These lateral roots don’t just spring out randomly. They appear and then branch out at regular intervals along a main axis, following a rhythm. What regulates and determines their development and rhythm was not known, until now.

In a new study, appearing August 26 in the journal Science, a research team led by Alexandra Dickinson, assistant professor at the University of California, San Diego, and Philip Benfey, the Paul Kramer Distinguished Professor of Biology at Duke University, identifies the compound that plays a key role in triggering the development of plants’ lateral roots.

The research team had a good suspect: retinal, a type of retinoid, looked like it would fit the bill.

In humans, as well as all vertebrate animals, turning a fertilized egg into an embryo with a little beating heart requires that stem cells differentiate, specialize, and generate specific tissues, such as bones, blood vessels and a nervous system. This process is kickstarted and regulated by retinal. Animals can’t produce their own retinal, though, they must ingest it from plants, or from animals that eat plants.