Our main interest is to understand the molecular circuits plants use to integrate environmental and developmental signals to produce specific responses. Towards this general goal we have been focusing on the identification of the molecular “signal integrators” or “logic gates” involved in the interaction between two plant hormones, ethylene and auxin, in the regulation of root growth. Using a multidisciplinary approach (genetics, molecular biology, genomics, metabolomics, cell biology, etc.), we have uncovered a complex multistep integration process with both spatial and temporal components.