AtMYB2 transcription factor can interact with the CMO promoter and regulate its downstream gene expression

The pC5 promoter, a region of the choline monooxygenase (CMO) promoter, contains an AtMYB2 transcription factor recognition sequence, TAACCA, and we have examined the interaction between AtMYB2 and the pC5 promoter. The AtMYB2 gene was cloned from Arabidopsis , expressed in Escherichia coli and transferred into pC5-GUS transgenic tobacco plants. Using an electrophoretic mobility shift assay, the AtMYB2 fusion protein binds to the TAACCA sequence in the pC5 promoter. As GUS activity was higher in pC5-GUS/AtMYB2 transgenic tobacco than in pC5-GUS plants, the AtMYB2 protein can bind to the CMO promoter in vitro and activate the transcription of the GUS reporter gene in vivo. The AtMYB2 transcription factor can therefore interact with the CMO promoter directly and regulate its downstream gene expression.