Fig. 7

Model of the role of ROXYs as repressors of the detoxification pathway. We postulate that redundant ROXYs bind to class II TGA factors at the promoters of detoxification genes repressing their activation by SCL14 [1] or other transcriptional co-activators. Upon TIBA treatment, the repressive capacity of ROXYs is abolished allowing activation of gene expression. This inactivation might be incomplete in plants expressing high amounts of ROXYs. Since control of gene expression is often subject to autoregulatory mechanisms, newly synthesized ROXYs including TIBA-induced ROXY19 might negatively regulate the inactivation mechanism in order to turn off the response. Ectopic expression of repressive ROXYs might interfere with this intricate mechanisms leading to permanent repression