The 6xABRE synthetic promoter enables the spatiotemporal analysis of ABA-mediated transcriptional regulation (Plant Physiol)

Abscisic acid (ABA) is known as stress hormone. Apart from its role in plant growth and development, it is widely studied due to its involvement in biotic and abiotic stresses. Although it had been studied for such a long time, a sensitive spatiotemporal marker for ABA is still elusive. Wu et al. developed an ABA responsive marker by using a synthetic promoter. Previous studies had shown that fusing short DNA fragments containing the ABRE (ABSCISIC ACID RESPONSIVE ELEMENT) with a minimal promoter (MP) sequence is sufficient to cause ABA-mediated expression. Here, the authors created a synthetic promoter using ABRE sequences from two well-characterized ABA responsive genes, RESPONSE TO DEHYDRATION 29A (RD29A) and ABA INSENSITIVE 1 (ABI1). The constructed marker responds to ABA in a tissue specific, time and concentration dependent manner, and is responsive to salt and mannitol. ABA-independent expression was also observed, suggesting that other, non-ABA factors interact with the synthetic promoter. Specifically, the quiescent-center specific WOX5 and NAC13  transcription factors regulate expression of the ABRE reporter. Taken together, this reporter will help to decipher stress regulation its interaction with development. (Summary by Arif Ashraf @aribidopsis) Plant Physiol. 10.1104/pp.18.00401