Scientists solve 50-year-old mystery behind plant growth

A team of researchers has demonstrated for the first time one way that a small molecule turns a single cell into something as large as a tree. For half a century, scientists have known that all plants depend on this molecule, auxin, to grow. Until now, they didn't understand exactly how auxin sets growth in motion.

source https://www.sciencedaily.com/releases/2021/11/211118203802.htm