Used to measure nitrate reductase (NR) activity in plant tissues, this ELISA kit enables researchers to assess nitrogen metabolism efficiency in plants. It is widely applied in agricultural and environmental studies to evaluate how plants utilize nitrogen from fertilizers, helping to optimize nutrient management and reduce environmental runoff. The kit supports research in crop breeding programs aimed at developing nitrogen-use-efficient plant varieties. It is also useful in stress physiology studies, where changes in NR activity indicate plant responses to drought, salinity, or nutrient deficiency. The assay is suitable for high-throughput analysis in laboratories focusing on plant biochemistry and sustainable agriculture.