Tuning the auxin transcriptional response

Abstract

Auxin is involved in almost every aspect of plant growth and development. How auxin orchestrates such diverse and context-specific responses has been a longstanding question. The work presented here evaluates the potential for specificity encoded within the short nuclear auxin pathway itself. By introducing each of the core components that make up the pathway into yeast, I was able to test how component choice and circuit configuration could be used to tune an auxin response. In building the pathway from perception to transcription in a heterologous context, I also defined the minimal requirements for a transcriptional auxin response. I went on to explore the potential for diverse responses in auxin circuits of varying complexity by individually substituting family members of the core components that make up the pathway. Finally, guided by the partial structures of the two key transcriptional regulators, I broke the pathway back down to systematically characterize the underlying protein-protein and protein-DNA interactions and generated a new minimal model of auxin signaling.