Arabidopsis nitrate-induced aspartate oxidase gene expression is necessary to maintain metabolic balance under nitrogen nutrient fluctuation.

Nitrate is a nutrient signal that regulates growth and development through NLP transcription factors in plants. Here we identify the L-aspartate oxidase gene (AO) necessary for de novo NAD biosynthesis as an NLP target in Arabidopsis. We investigated the physiological significance of nitrate-induced AO expression by expressing AO under the control of the mutant AO promoter lacking the NLP-binding site in the ao mutant.