Used to measure nitrite reductase (NiR) enzyme activity in plant tissues, this ELISA kit helps researchers assess nitrogen metabolism and assimilation efficiency in plants. It is widely applied in plant physiology and agricultural studies to evaluate how plants utilize nitrogen from the environment, especially under stress conditions or in different soil types. The kit enables high-throughput analysis, making it valuable for screening crop varieties with improved nitrogen use efficiency, supporting sustainable agriculture and reducing fertilizer dependency. It is also used in environmental plant research to study responses to nitrate availability and pollution.