Before revision:  The BR signalling pathway acts by altering the phosphorylation state of its transcription factors BZR1/2, whereas the GA signalling pathway acts by reducing the stability of its transcription factor DELLA. Both signalling pathways include a negative feedback, with high levels of BR causing increased repression of key BR-biosynthetic genes mediated by BZR1/2, and high levels of GA causing decreased stability of DELLA, where DELLA is responsible for activating key genes involved in GA biosynthesis. We derive and analyse new mathematical models for the BR signalling pathway and  the crosstalk between the BR and GA signalling pathways.
After revision:  In this paper we derive and analyse new mathematical models for the BR signalling pathway and the crosstalk between the BR and GA signalling pathways.