Hydrogen-rich water ameliorates the toxicity induced by Ca(NO 3 ) 2 excess through enhancing antioxidant capacities and re-establishing nitrate homeostasis in Brassica campestris spp. chinensis L. seedlings

The accumulation of calcium nitrate [Ca(NO 3 ) 2 ] in the edible part of vegetables is one of the main reasons for the reduction of production and is harmful to human health, but so far, there is no effective method to solve environmentally problem. In this study, an environmentally friendly hydrogen-rich water (HRW) was used to study its effect on alleviating the growth inhibition of Brassica campestris spp. chinensis L. seedlings exposed to excessive Ca(NO 3 ) 2 . The results of Chinese cabbage seedlings exposed to excessive Ca(NO 3 ) 2 showed that the nitrate content in edible parts of seedlings was reduced by exogenous HRW by promoting seedling growth, reducing oxidative stress, and reducing the excess of 80 mM Ca(NO 3 ) 2 which was toxic effects in the edible part of the seedlings. The conclusion was supported by the following results: (1) when Ca(NO 3 ) 2 was added excessively, HRW could effectively reduce the growth inhibition of Chinese cabbage seedlings by increasing root lengths and leaves and roots weights; (2) HRW inhibited the accumulation of the O 2 ·− , H 2 O 2 , MDA and the conductivity of relative electrical under Ca(NO 3 ) 2 through increasing the activity of antioxidant enzymes (SOD, POD, CAT, APX); (3) HRW was processed by transporters ( BcNRT1.5 and BcNRT1.8 ), which allowed more nitrates to be stored in the roots and reduces transport to the ground.