Regulation effect of nitrate nitrogen on chromium toxicity to Brassica campestris L. ssp. chinensis (L.)
硝态氮对小白菜铬污染毒性的调控作用

Pot and water culture experiments were conducted to study the regulation effects of nitrate nitrogen on chromium toxicity to Brassica campestris L.ssp.chinensis(L.).The results showed that exogenous Cr6 could obviously promote the chromium accumulation in B.campestris,restrain its iron uptake,and inhibit its nitrate reductase activity;while nitrate nitrogen could alleviate the inhibitory effect of Cr6 on the iron absorption and nitrate reductase activity of B.campestris,enhance its nitrogen metabolism and vitamin C biosynthesis,and stimulate plant growth.Under the same conditions of soil chromium contamination,the increase of nitrate nitrogen promoted the transformation of exogenous Cr6 into organic form,and the Cr6 uptake by B.campestris.It was concluded that nitrate nitrogen could promote the plant growth and Cr6 absorption of B.campestris,and obviously increased its Cr6 accumulation.