A key protein acts as a primary nitrate sensor for land plants, according to a Chinese-led study published in the journal Science on Thursday.

Nitrate is an essential nutrient and signaling molecule for plant growth. Plants sense intracellular nitrate to adjust their metabolic and growth responses. In agricultural production, nitrate is an important factor that increases crop yields.

Researchers from China's Northwest Agriculture and Forestry University (NWAFU), Harvard Medical School and the University of Tokyo found that NIN-like protein 7 (NLP7) serves as both nitrate signal switch and nitrate receptor.

They also developed fluorescent nitrate receptors to observe nitrate levels and changes in plants at the cellular level.

According to the NWAFU, the study illustrates "the regulatory mechanism that photoautotrophic plants use to activate the plant signal transduction network" and "growth response by sensing nitrate."

The study will provide new insights to help improve nitrogen use efficiency in crops, reduce fertilizer use and energy consumption, mitigate climate change caused by greenhouse gas emissions, and support sustainable agricultural development, said the university.

(With input from Xinhua)