Plant Hormones (IMAGE) National Institutes of Natural Sciences Caption It is the long-distance communication from the roots to the leaves and back again from those leaves to the roots that maintains the proper number of root nodules. Credit Masayoshi Kawaguchi Usage Restrictions None 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.