Architecture of DNA elements mediating ARF transcription factor binding and auxin-responsive gene expression in Arabidopsis

Significance The plant hormone auxin controls many aspects of growth and development. It does so by changing the activity of AUXIN RESPONSE FACTOR (ARF) proteins that recognize specific DNA elements in plant genes and switch gene expression on or off. A major question in plant biology is how these ARF proteins bind unique DNA sequences and thus select which genes are regulated by auxin. Here, the authors systematically study the DNA architecture required for high-affinity binding of ARF proteins, and for auxin-dependent gene regulation in the plant Arabidopsis thaliana . This work shows that repeats of ARF recognition sites are critical for function, and reveals the molecular basis for the distinct activities of different repeat structures.