Root Or Shoot? Ear Calls The Shots (IMAGE) Salk Institute Caption The lens shaped cell (shown in green) at the base of the plant embryo (shown in red) will go on to form the center of the root meristem -- the actively dividing cell tissue at the tips of roots. It fluoresces green in response to auxin, which governs root development (far left). Embryos with a mutation in the TOPLESS gene still respond normally to auxin (second from left), while embryos without a functional version of BODENLOS cannot respond to auxin and as a result fail to develop roots (second from right). Combining both mutations restores the auxin response as well as root development (far right). Credit Images: Courtesy of Dr. Jeffrey Long, Salk Institute for Biological Studies Usage Restrictions Usage Restrictions: News media reproduction to illustrate this story permitted with proper attribution as provided above. For one time use only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.