Selection for Cd Pollution-Safe Cultivars of Chinese Kale (Brassica alboglabra L. H. Bailey) and Biochemical Mechanisms of the Cultivar-Dependent Cd Accumulation Involving in Cd Subcellular Distribution

Abstract

Two pot experiments were conducted to compare and verify Cd accumulation capacities of different cultivars under Cd exposures (0.215, 0.543, and 0.925 mg kg in Exp-1 and 0.143, 0.619, and 1.407 mg kg in Exp-2) and Cd subcellular distributions between low- and high-Cd cultivars. Shoot Cd concentrations between the selected low- and high-Cd cultivars were 1.4-fold different and the results were reproducible. The proportions of Cd-in-cell-wall of shoots and roots were all higher in a typical low-Cd cultivar (DX102) than in a typical high-Cd cultivar (HJK), while those of Cd-in-chloroplast or Cd-in-trophoplast and Cd-in-membrane-and-organelle were opposite. The proportions of Cd-in-vacuoles-and-cytoplasm of roots in DX102 were always higher than in HJK under Cd stresses, while there was no clear pattern in those of shoots. These findings may help to reduce health risk of Cd from Chinese kale consumption and explained biochemical mechanisms of cultivar-dependent Cd accumulation among the species.

Environmental Chemical Contaminants in Food: Review of a Global Problem

“…Interestingly, the study also showed increased uptake of cadmium in rice crops planted after the oilseed rape harvest, with contamination of rice higher compared to a crop after a fallow period. Another mechanism of plants which can be used advantageously is that of reduced accumulation of unwanted chemicals in certain cultivars or altered plant hybrids—for example in Chinese kale—and these can be selected to produce safer food [168].…”

Selection for low-cadmium cultivars and cadmium subcellular distribution comparison between two selected cultivars of eggplant (Solanum melongena L.)

“…The subcellular distribution of Cd was measured using the method described by Guo et al (2018). The root, stem, and leaf tissues of each frozen sample were homogenized on ice in the presence of extraction buffer (50 mM Tris-HCl, 250 mM sucrose, 1.0 mM C 4 H 10 O 2 S 2 , and 5.0 mM ascorbic acid).…”

“…Biomass response to stress is a common method for detecting Cd tolerance in plants (Wang et al 2009;Guo et al 2018). In this study, two Cd concentrations were used: low-Cd (2.9 mg/kg) and high-Cd (4.7 mg/kg), which covered most of the concentration range of arable land Cd contamination in South China (He et al 2020;Mamat et al 2020).…”

“…Under high-Cd treatment, only 10 out of the 30 eggplant cultivars showed a relatively signi cant reduction in biomass, while ve cultivars even showed a signi cant increase in biomass, indicating that high levels of Cd tolerance and signi cant inter-cultivar differences in Cd tolerance exist in eggplants, coinciding with the results of a study on eggplant seedlings by Jiao et al (2013). As with numerous studies, the Cd accumulation capacity of plants is usually stable and genotype dependent (Grant et al 2008;Guo et al 2018;He et al 2018). Likewise, fruit Cd concentrations of the 30 tested eggplant cultivars showed almost the same order under low-or high-Cd treatment (Figure 4), indicating that eggplant Cd accumulation ability should also be determined by the genotype of cultivars.…”

“…To date, the Cd-PSC strategy has been utilized in water spinach (Ipomoea aquatica Forsk.) (Wang et al 2009), Chinese owering cabbage (Brassica campestris L) (Qiu et al 2011), hot pepper (Capsicum annuum L.) (Xin, Huang, Liu, et al 2013), leafy lettuce (Lactuca sativa L.) (Zhang et al 2013), pakchoi (Brassica chinensis L.) (Zhou et al 2016), and Chinese kale (Brassica alboglabra L.) (Guo et al 2018); the Cd concentrations of edible parts in these low-Cd cultivars are 60-80%, lower than those of the high-Cd cultivars on average. Eggplant (Solanum melongena L.) is a vegetable of great economic and nutritional value that has been widely cultivated worldwide, especially in China (Saini and Kaushik 2019).…”