Search

The accumulation of calcium nitrate [Ca(NO3)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(NO3)2. The results of Chinese cabbage seedlings exposed to excessive Ca(NO3)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(NO3)2 which was toxic effects in the edible part of the seedlings. The conclusion was supported by the following results: (1) when Ca(NO3)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 O2·−, H2O2, MDA and the conductivity of relative electrical under Ca(NO3)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. [ABSTRACT FROM AUTHOR]

Glutathione (GSH) is involved in not only plant developmental processes but also plant responses to abiotic stresses. A hydroponic experiment was performed to explore the protective roles of exogenous GSH in mitigating cadmium (Cd) stress in Brassica campestris L. seedlings by analyzing the morphological and physiological parameters. Results showed that Cd caused severe growth inhibition and Cd accumulation. However, application of GSH significantly mitigated toxic symptoms induced by Cd, including the improvement of the photosynthesis-, plant growth-, and root morphology-related parameters in seedlings under Cd stress. These responses were associated with a striking increase in activities of representative antioxidative enzymes and contents of corresponding non-enzymatic antioxidants. In vivo imaging of O2.- and H2O2, and the detection of lipid peroxidation further demonstrated that increased ability by GSH for Brassica campestris L. seedlings to endure Cd stress was consistent with a striking elevation of ratios of reduced to oxidized glutathione (GSH/GSSG) and ascorbic acid to dehydroascorbic acid (AsA/DHA). Additionally, GSH application increased Cd retained in roots, thus significantly decreased its translocation from root to shoot, ultimately decreased Cd accumulation in shoots. Taken together, our results proved evidence for GSH in ameliorating Cd toxicity via reducing Cd accumulation in shoots and increasing oxidation resistance. Accordingly, application of GSH could be a high-efficiency and promising strategy to decrease Cd concentration in edible parts of Brassica campestris L. in agricultural production. [ABSTRACT FROM AUTHOR]

To evaluate the effects of different partial shading treatments on the synthesis of anthocyanins under UV-A irradiation in soybean sprouts, we examined the anthocyanin content, transcript levels of key genes related to anthocyanin biosynthesis ( CRY1, CRY2, PAL, CHS, CHI, DFR, ANS and UFGT), and the activity of phenylalanine ammonia-lyase (PAL). The results showed that UV-A radiation could significantly increase the content of anthocyanins in the epidermal layer of hypocotyls in soybean sprouts. This trend was consistent with the pattern of anthocyanin biosynthesis-related gene expressions, which were significantly up-regulated by UV-A. Different partial shading treatments significantly reduced the content of anthocyanins and the expression of DFR, ANS, and UFGT in response to the UV-A irradiation. Cotyledon-shading treatment lowered the content of anthocyanin due to the down-regulation of the expression of anthocyanin biosynthesis-related genes, but this effect is limited. Compared with the cotyledon and the upper part of hypocotyls, the lower part of hypocotyls was the predominant site of anthocyanin synthesis in soybean sprouts. These findings imply that anthocyanins in hypocotyls are biosynthesised locally, and there is no systemic biosynthesis, which was further supported by the PAL activity and the transcripts of the genes responsible for anthocyanin biosynthesis. [ABSTRACT FROM AUTHOR]

To investigate how light quality influences tomato ( Solanum lycopersicum L) seedlings, we examined changes in plant growth, chloroplast ultrastructure, photosynthetic parameters and some photosynthesis-related genes expression levels. For this, tomato plants were grown under different light qualities with the same photosynthetic photon flux density: red (R), blue (B), yellow (Y), green (G) and white (W) lights. Our results revealed that, compared with plants grown under W light, the growth of plants grown under monochromatic lights was inhibited with the growth reduction being more significant in the plants grown under Y and G lights. However, the monochromatic lights had their own effects on the growth and photosynthetic function of tomato seedlings. The plant height was reduced under blue light, but expression of rbcS, rbcL, psbA, psbB genes was up-regulated, and the ΦPSII and electron transport rate (ETR) values were enhanced. More starch grains were accumulated in chloroplasts. The root elongation, net photosynthetic rate (Pn), NPQ and rbcS and psbA genes expression were promoted under red light. Yellow light- and green light-illuminated plants grew badly with their lower Rubisco content and Pn value observed, and less starch grains accumulated in chloroplast. However, less influence was noted of light quality on chloroplast structure. Compared with yellow light, the values of ΦPSII, ETR, qP and NPQ of plants exposed to green light were significantly increased, suggesting that green light was beneficial to both the development of photosynthetic apparatus to some extent. [ABSTRACT FROM AUTHOR]