The Responses of Salt-Affected Plants to Cadmium

Zinc and Cadmium Mapping in the Apical Shoot and Hypocotyl Tissues of Radish by High-Resolution Secondary Ion Mass Spectrometry (NanoSIMS) after Short-Term Exposure to Metal Contamination

“…Finally, large variation exists among plant species and genotypes in accumulation of trace metals in roots (hypocotyl) and distribution to shoots [4,5,40]. Significant research effort with different radish genotypes has been devoted to elucidation of trace element pathways from rhizosphere to plants [36] as well to their morphological/anatomical [42], physiological [43], and biochemical and genomic [15,16,44,45] characterisation.…”

“…Future research may explore potential differences among radish genotypes to accumulate Cd as one of sustainable approaches for utilising land with elevated Cd concentration in soil [15] and lowering the risk of toxic Cd entering into our food chain. Traditional breeding techniques in combination with transgenic approaches have been highlighted as a promising strategy for improving crop food/feed production in certain environmentally constrained conditions such as elevated Cd concentration in soil [4,5,15] and increased salinity [46]. For instance, Yu et al [47] identified 30 rice cultivars (among 43 tested) that maintained Cd concentration in grain within the limits safe for human consumption when grown on Cd-contaminated soil (1.75 mg Cd/kg soil).…”

“…Understanding of trace metal homeostasis and phyto-physiological processes has expanded considerably in recent decades and is being used in phytoremediation technologies (i.e., clean-up of metal-contaminated land by plants) (e.g., [1]), bio-fortification of food (i.e., improving nutritive value of crops regarding essential trace metals) (e.g., [2]) as well food safety/security from metal contamination (i.e., growing “metal-clean” food) [3]. Given that trace metals can accumulate in edible tissues (particularly underground ones, such as roots, tubers and hypocotyls) and/or primary nutrient deposition sites (e.g., young shots), consumption of vegetables (especially fresh (non-processed) that are nutritive highly valued) is one of the main entry routes of certain trace metals (Cd, Zn, Hg) into humans [4,5,6,7]. Over the last several decades, trace heavy metal Cd was one of the most frequently reported hazards (after mycotoxins, pathogens and pesticide residues) in the Rapid Alert System for Food and Feed [7] regulated by the European Food Safety Authority.…”

“…In most organisms (except, e.g., marine phytoplankton [8,9]), Cd has no biological function, representing threat to environmental/public health due to its role in a wide range of toxicological (e.g., growth retardation, yield reduction, and necrosis) and physiological disorders (e.g., hormonal disruption, carcinogenesis, alterations in vitamin metabolism and (re)absorption of nutrients, triggering secondary (oxidative) stress) [4,6,10] (see also review by Huang et al [5]). It is well known that similar physicochemical properties of the bioavailable forms of zinc (as an essential micronutrient; Zn 2+ ) and cadmium (Cd 2+ ) (e.g., [9]) result in competition for adsorption sites in the rhizosphere, uptake across the root–cell plasma membrane, and transport to shoots [4]. Thus, increased relative abundance of one element (e.g., Zn) could suppress the rhizosphere-to-plant transfer and deposition of the other (e.g., Cd).…”

Sodium chloride decreases cadmium accumulation and changes the response of metabolites to cadmium stress in the halophyte Carpobrotus rossii

“…It has been widely reported that NaCl, as the most common salt in saline soils, can increase Cd uptake and accumulation in plants when grown in Cd-contaminated soils due to increased total Cd concentrations in soil solution (Smolders et al, 1998;Weggler-Beaton et al, 2000;Ghallab and Usman, 2007;Ondrasek, 2013). Several possible mechanisms have been described in the literature to explain this greater Cd bioavailability.…”