[Research progress on the effects of atmospheric nitrogen dioxide on plant growth and metabo-lism].

Nitrogen dioxide (NO2) is one type of the atmospheric nitrogen oxides, which is the main component of atmospheric aerosol particles. Reducing the concentration of atmospheric NO2 can decrease the haze in the air. Atmospheric NO2 deposits on plant leaves by both dry and wet deposition. After leaf absorption, atmospheric NO2 was reduced by two metabolism ways: one was the nitrogen metabolism by reductase mainly in cytoplasm and chloroplast, and the other was the pathway of NO2 decomposition reaction in the apoplast and cytoplasm. Plant absorption of NO2 disturbs plant normal growth and physiological metabolism, including vegetative growth and reproductive growth, nitrate reductase (NaR) activity, nitrite reductase (NiR) activity, nitrogen uptake, photosynthetic and other physiological metabolic processes. Here, we reviewed the research progress on the effects of atmospheric NO2 on plant growth and metabolism, and proposed the future research direction of physiological and molecular mechanism of atmospheric NO2 absorption by plants.