Effects of Cadmium on Root Morpho-Physiology of Durum Wheat

Abstract

Durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] can accumulate a high level of Cd in grains with a significant variability depending on cultivars. Understanding how this toxic element is distributed in cereal tissues and grains is essential to improve the nutritional quality of cereal-based products. The main objective of this work was to investigate roots of durum wheat plants (cv. Iride) exposed to different Cd concentrations (0.5 and 5.0 μM) to identify the mechanisms involved in Cd management. Results showed that the root morphology was altered by Cd treatment both at macroscopic (increased number of tips and primary root length) and ultrastructural levels (cell membrane system damaged, cell walls thickened and enriched in suberin). On the other side, Cd was localized in vesicles and in cell walls, and the metal colocalized with the phytosiderophore nicotianamine (NA). Overall, data suggest that Cd is chelated by NA and then compartmentalized, through vesicular trafficking, in the root thickened walls reducing Cd translocation to the aerial organs of the plant.

Effect of Cadmium Toxicity on Different Antioxidant Enzymes in Growing Wheat (Triticum aestivum L.) Seedlings

“…The growth of seven-day-old wheat seedlings gradually declined when they were exposed to Cadmiuminduced stress. Cd is one of the most noxious, toxic, and harmful heavy metals that frequently become available in the climate (Sabella et al, 2022). Due to its toxic nature on living beings, it is not required for plant nutrition or soil (Abbas et al, 2018).…”

“…So, the amount of the generated reactive oxygen species has maintained a specific physiological phenomenon by the antioxidant enzymes (e.g., catalase, peroxidase, etc.) under a steady state, including salinity, drought and toxicity of metal may cause a substantial rise in the reactive oxygen species levels through disrupting the oxidative homeostasis (Kobeya, 2020;Sabella, 2022). Phosphorus (P) is a very important component for the metabolism of cells in every plant.…”

“…Acid phosphatases (orthophosphoric monoester phosphohydrolases) being overlapping and broad specificities of substrate are very much pervasive and the enzymes abundant in various plant species. Acid phosphatases catalyse the non-specific hydrolysis in the ranges of pH 4-6 and show a specific role in metabolism and phosphate supply in plants (Sabella, 2022;Gutiérrez-Martínez, 2020). Equivalently, the enzyme alkaline phosphatases show a vital role in the utilization of phosphomonoesters that are required for the maintenance of the metabolism of cells (Mamun et al, 2018;.…”

Responses of Spring Barley to Zn- and Cd-Induced Stress: Morphometric Analysis and Cytotoxicity Assay

“…Inhibition of root extension, lateral root development, and induction of root tip radial swelling were the main root morphological changes induced by Cd. Earlier toxic effects of Cd on the root morphology of durum wheat were found as increases in the number of tips and primary root length, damages in the cell membrane system, and thickness in the cell wall [ 51 ]. According to recent findings, cell walls are essential for improving plant Cd tolerance because they restrict the metal from entering the root cells [ 52 , 53 ].…”

Convergence between Development and Stress: Ectopic Xylem Formation in Arabidopsis Hypocotyl in Response to 24-Epibrassinolide and Cadmium

“…We think that this relationship is possible because, in barley roots, Cd stimulates premature xylem formation within the stele [ 35 ]. Moreover, the pericycle is a tissue targeted by Cd, which affects the responses of its cells, e.g., by increasing cell wall thickening, as in durum wheat [ 36 ], or by enhancing their number, as in bean roots [ 37 ].…”