Novel vitalization effect of atmospheric reactive nitrogen species on plants

Abstract

Atmospheric NOx, which includes nitric oxide and nitrogen dioxide, is usually regarded to act as N source or to exert detrimental effects on plants. When Nicotiana plumbaginifolia were cultured in air with ¹⁵N-labelled NOx (100 to 200 ppb) and in NOx-free (<5 ppb) air for several months, the biomass yield, element contents, total free amino acids and crude proteins were almost two times greater in plants cultured in the "polluted air" than those cultured in the "clean air". Furthermore, Isotopic mass spectrometry has shown that the nitrogen derived from NOx made only a negligible contribution in the total nitrogen of plants. We are currently investigating the effects of atmospheric NOx on other plant species. Our findings indicated that the atmospheric NOx vitalizes plants.