Plant metabolism and alkaloid levels can be regulated by transcription factors that regulate the nicotinic alkaloid biosynthetic pathway. In one embodiment, the disclosure provides a transcription factor that positively negatively regulates alkaloid biosynthesis, such as nicotine biosynthesis. In particular, the present disclosure provides methods for the inhibition of Nicotiana benthamiana auxin response factor 1 (NbTF1) to reduce alkaloid biosynthesis in plants.