Cadmium uptake and translocation in durum wheat varieties differing in grain-Cd accumulation

Abstract

Wheat grain products are the primary source of dietary Cd-intake for humans. Since varieties differ markedly in grain-Cd accumulation, efforts are needed to find traits associated with low, or high, accumulation. Two durum wheat varieties, selected in a field screening as low (Creso) and high (Svevo) grain-Cd accumulating, were grown on soil spiked with 1.5, 3 and 4.5 mg Cd/kg. Growth patterns, Cd uptake and translocation were investigated at heading and maturity. Cadmium did not affect plant growth and grain yield, but grain-Cd concentration always exceeded the permissible limit of 0.2 mg Cd/kg, and was approximately double in Svevo than in Creso. At maturity, total Cduptake increased linearly with supply in Creso, from 13 to 23 µg/plant, and was approximately 18 µg/plant, irrespective of Cd level, in Svevo. Partitioning to shoot was higher in Svevo than in Creso, both at heading and maturity. We suggest that reduced plant height, high root to shoot biomass ratio during vegetative growth and elevated postheading dry matter accumulation promoted Cd accumulation into grain. Since these traits are common to modern wheat varieties, risks of grain Cd-contamination can increase in the future.

Absorption and distribution of cadmium of three maize hybrids in three environments

“…As expected, the Cd rate used was directly proportional to soil concentration (Figure 3b), which coincides with findings reported in the literature (Arduini et al, 2014;Fahad et al, 2015); both applied CdCl 2 rates were higher than the critical threshold of this element in soils (1 mg kg -1 ). Regarding the maize cultivars under study, no effect was recorded on soil total Cd concentration ( Figure 3c).…”

“…However, applying increasing Cd rates produced an increase of more than 100% in maize grain Cd accumulation when compared with the control with no applied Cd (Arduini et al, 2014;Yang et al, 2014). Although differences among environments were found in the controls, this fact could be related to the initial total soil Cd concentration (Table 2); this has been reported by numerous authors (Degryse et al, 2009;Yang et al, 2014).…”

“…Although differences among environments were found in the controls, this fact could be related to the initial total soil Cd concentration (Table 2); this has been reported by numerous authors (Degryse et al, 2009;Yang et al, 2014). On the other hand, differences in grain Cd concentration detected among environments could be due to higher mineral use efficiency (Arduini et al, 2014 Wahsha et al (2014), which was probably due to the initial soil Cd concentration as indicated by Putwatana et al (2015). Maize straw…”

The Uptake, Accumulation, and Toxic Effects of Cadmium in Barnyardgrass (Echinochloa crus-galli)

“…Cadmium contents were significantly increased with 0.6, 0.9, and 1.5 mg·kg -1 Cd stresses in roots, indicating that uptake of Cd in roots is a key process in barnyard grass plant Cd accumulation. Similar results were reported in various plants [23][24]. Aboveground parts exposed to 0.9 and 1.5 mg·kg -1 Cd showed a significantly higher Cd accumulation than that of the control.…”

“…E. crus-galli can produce large number of seeds and grow better than crop plants in adverse environments, e.g., in nutrientdeficient and/or contaminated soil. It may cause a 21-79% yield loss in rice, depending upon the cropping system and management [14][15]. Interestingly, there is increased evidence showing that E. crus-galli may play an important role in improving heavy metal-contaminated soil [3,[17][18].…”