分类: 生物学 >> 植物学 提交时间: 2018-01-10
摘要: A pot experiment was conducted to investigate the effects of calcium silicate (CS) on the subcellular distribution and chemical forms of cadmium (Cd) in grain amaranths (Amaranthus hypochondriacus L. Cv. 'K112') grown in a Cd contaminated soil. Results showed that the dry weight and the photosynthetic pigments contents in grain amaranths increased significantly with the increasing doses of CS treatments, with the highest value found for the treatment of CS3 (1.65 g/kg). Compared with the control, application of CS4 (3.31 g/kg) significantly reduced Cd concentrations in the roots, stems and leaves of grain amaranths by 68%, 87% and 89%, respectively. At subcellular level, CS treatment resulted in redistribution of Cd, higher percentages of Cd in the chloroplast and soluble fractions in leaves of grain amaranths were found, while lower proportions of Cd were located at the cell wall of the leaves. The application of CS enhanced the proportions of pectate and protein integrated forms of Cd and decreased the percentages of water soluble Cd potentially associated with toxicity in grain amaranths. Changes of free Cd ions into inactive forms sequestered in subcellular compartments may indicate an important mechanism of CS for alleviating Cd toxicity and accumulation in plants.
分类: 生物学 >> 生态学 提交时间: 2018-01-10
摘要: The health risks associated with the consumption of rice may decrease if consumers use cooking practices which can reduce the concentrations of metal(loid)s and their bioaccessibility. The effects of cooking on the bioaccessibility of Cd and As in three contamination levels of rice were studied. The results indicated that cooking reduced bioaccessibility of Cd and As in rice. Cooking resulted in a significant increase in Cd and As concentrations in the residual fraction. Low volume cooking rice to dryness remove total Cd by about 10% for rice A and B, while middle or high volume water had no effect on Cd bioaccessibility in all rice types. In contrast, low volume cooking did not remove As, but a significant decrease was observed when cooking with middle or high volume water. This study provides information for a better understanding of more realistic estimation of metal(loid)s exposure from rice and the possible health risks.