Root Growth (IMAGE) Howard Hughes Medical Institute Caption Normally, the hormone auxin makes roots short. A new, synthetic version of the hormone does the same thing, researchers discovered. Exposure to increasing levels of synthetic auxin (left to right) decreased root length in seedlings engineered to detect the hormone. Credit N. Uchida et al./<i>Nature Chemical Biology</i> 2018 Usage Restrictions Use with credit. 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.