Cadmium (Cd) in soil and water streams is now recognized as a significant environmental issue that harms plants and animals. Plants damaged by Cd toxicity experience various effects, from germination to yield reduction. Plant- and animal-based goods are allowing more Cd to enter our food chain, which could harm human health. Therefore, this urgent global concern must be addressed by implementing appropriate remedial measures. Plant-based phytoremediation is one safe, economical, and environmentally acceptable way to remove hazardous metals from the environment. Hyperaccumulator plants possess specialized transport proteins, such as metal transporters located in membranes of roots, as well as they facilitate Cd uptake from soil. This review outlines the latest findings about these membrane transporters. Moreover, we also discuss how innovative modern tools such as microbiomes, omics, nanotechnology, and genome editing have revealed molecular regulators connected to Cd tolerance, which may be employed to develop Cd-tolerant future plants. We can develop effective solutions to enhance tolerance of plant to Cd toxicity by leveraging membrane transporters and modern biotechnological tools. Additionally, implementing strategies to increase tolerance of Cd and restrict its bioavailability in plants' edible parts is crucial for improving food safety. These combined efforts will lead to the cultivation of safer food crops and support sustainable agricultural practices in contaminated environments.

Natural Resistance-Associated Macrophage Protein (NRAMP), a class of metal transporter proteins widely distributed in plants, is mainly involved in the uptake and transport by plants of metal ions, such as iron, manganese and cadmium. The current study is the first to fully investigate the Triticum aestivum (T. aestivum) NRAMP gene family. 33 NRAMP members were identified from the entire T. aestivum genome and classified into three main groups based on related genes found in five other species. Among the TaNRAMP genes, the exon-intron structure and motif composition exhibited significant similarity among members of the same evolutionary branch of the phylogenetic tree. Based on RNA-seq and qRT-PCR analyses, we identified the expression patterns of the TaNRAMP genes in different tissues and under various stress conditions. TaNRAMP genes expression were responsive to induction by cadmium (Cd). Overexpression of the TaNRAMP5 gene enhanced wheat and tobacco tolerance to Cd toxicity. Additionally, the TaNRAMP5 protein physically interacted with protein phosphatase 2A (PP2A) in yeast cells. This study provides a valuable reference point for further investigations into the functional and molecular mechanisms of the NRAMP gene family.

Stress Associated Proteins (SAPs) contain A20/AN1 zinc finger domains and, have been proposed to function in various physiological processes such as cold, salinity, drought, heavy metals, damage, and flooding resistance in plants. Here, a total of 131 SAP genes were identified, including T. aestivum (60), T. urartu (10), Ae. Tauschii (16), T. dicoccoides (13), O. sativa (18), and A. thaliana (14). A phylogenetic analysis revealed that the SAPs are clustered into two subfamilies. The TaSAP genes in the collinear region comprised 34 pairs of duplicated genes formed through segmental duplication events. Overexpressing TaSAP6-A1 in wheat enhanced Cd tolerance, whereas knock-down of this gene increased Cd sensitivity. Yeast two-hybrid (Y2H) and bimolecular fluorescent complementation assays (BiFC) demonstrated interaction between TaSAP6-A1 and phenylalanine ammonia-lyase (TaPAL), the first enzyme in the phenylpropanoid pathway. This study provides a valuable reference for further investigations into the functional and molecular mechanisms of the SAP gene family.

ETHYLENE INSENSITIVE 2 (EIN2), as the core component of the ethylene signaling pathway, can widely regulate plant growth, development, and stress responses. However, the comprehensive study and function of EIN2 in wheat Cadmium (Cd) stress remain largely unexplored. Here, we identified 33 EIN2 genes and designated as TaEIN2-2B to TaEIN2-Un.3 in Triticum aestivum. The analysis of cis-regulatory elements in promoter regions and RNA-Seq showed that TaEIN2s were functionally related to plant growth and development, as well as the response to biotic and abiotic stress. qRT-PCR analysis of TaEIN2s indicated their sensitivity to Cd stress. Compared with WT plants, TaEIN2-4D.1-RNAi transgenic wheat lines showed enhanced shoot and root elongation, dry weight and chlorophyll accumulation, together with a reduced accumulation of Cd in wheat grain. In addition, TaEIN2-4D.1-RNAi transgenic wheat lines showed enhanced Reactive Oxygen Species (ROS) scavenging capacity compared with WT plants. In conclusion, our research indicates that TaEIN2 plays a key role in response to cadmium stress in wheat, which provides valuable information for crop improvement.