Effects of node restriction on cadmium accumulation in eight Chinese wheat (Triticum turgidum) cultivars

Minimization of cadmium (Cd) accumulation in wheat is an effective method to prevent Cd-related health risks to humans. To understand the underlying mechanisms of restricting Cd transport, the role of nodes in Cd restrictionwas studied in eight Chinesewheat cultivars. The Cd accumulation differed significantly among the cultivars. The grain Cd concentrations were mainly dependent on the Cd concentrations in the roots and shoots. The Cd transport in the shoots controlled thewheat grain Cd accumulations. Nodes in thewheat stemhave distinct functions in the transfer, distribution, and restriction of Cd. The node connected to the panicle showed the lowest translocation factors. The area of the vascular bundles, especially the diffuse vascular bundles, in the junctional nodewith the flag leafwas the key factor in restricting Cd transfer to the wheat grain. There was a significant relation between these areas and the grain Cd concentrations. The conclusion of this study is that screening or breeding cultivars with low Cd concentrations in the roots or with smaller areas of diffuse vascular bundles in the junctional nodes with the flag leaf is an effective strategy to decrease Cd concentration in wheat grains. (C) 2020 Elsevier B.V. All rights reserved.