Nitrogen as an important detoxification factor to cadmium stress in poplar plants

[摘要] To verify the important role of nitrogen in detoxifying plants from heavy metals in Populus , the influence of nitrogen and cadmium on growth, chlorophyll (Chl) synthesis, and the expression of the Glutamine synthetase gene ( GS 2 ) were studied in poplar plants. Experiments were carried out in potted plants treated with (NH 4 ) 2 CO 3 , Cd(NO 3 ) 2 , CdCl 2 and CdCl 2 plus (NH 4 ) 2 CO 3 . After treatment, plant height, biomass, chlorophyll content, the precursors content and GS 2 were investigated. Results showed that the plants treated with cadmium showed toxicity symptoms, decrease in growth and Chl content. Cd inhibited Chl synthesis seriously by blocking the site located on the steps between UrogenIII and Coprogen III. However, the plants treated with cadmium and nitrogen grew well without any toxicity symptoms. Nitrogen supplement can alleviate Cd inhibition on chlorophyll synthesis by unblocking the pathway. The results indicated that nitrogen can effectively alleviate cadmium toxicity to poplar plants.

[学科分类] 纳米科学和纳米技术

[关键词] poplar;cadmium;nitrogen;growth;chlorophyll synthesis;Glutamine synthetase II gene