The present invention relates nucleic acid molecules that are modulated (e.g., upregulated) by nitrogen in corn, to proteins or polypeptides encoded by these nucleic acid molecules, and promoters of these nucleic acid molecules. The present invention relates to a nucleic acid construct having a nucleic acid molecule that is modulated by nitrogen in corn, as well as to expression systems, host cells, plants, and plant seeds having the nucleic acid construct. The present invention also relates to a method of expressing the nucleic acid molecule that is modulated by nitrogen in a plant by growing a transgenic plant or a plant grown from a transgenic seed transformed with the construct. The present invention further relates to an isolated DNA promoter that can be used to direct nitrogen-regulated expression of an isolated nucleic acid in plants.