Radish genes control cadmium absorption and removal from plants

Greg Howard
14th February, 2026

Radish genes control cadmium absorption and removal from plants

The radish gene RsPDR12 is strongly induced by cadmium (Cd) stress, as shown by increased gene expression in roots (a) and promoter activation in Nicotiana benthamiana leaves (c, e, f), and its protein localizes to the plasma membrane (b), indicating its involvement in the plant's response to heavy metals.

Image adapted from: Ma et al. / CC BY (Source)

Key Findings

  • In radish plants, the RsPDR12 gene’s activity increases when exposed to cadmium, suggesting a role in Cd response
  • RsPDR12 actively transports cadmium, reducing its levels in yeast cells and roots of Arabidopsis, indicating it helps remove Cd
  • The RsWRKY15 gene directly activates RsPDR12, increasing its expression and ultimately lowering cadmium accumulation in radish
Cadmium (Cd) is a heavy metal that poses a significant threat to food safety, particularly in root vegetables like radish where it accumulates. This accumulation not only reduces the quality of the radish but also introduces a health risk to consumers. Understanding how plants manage Cd uptake is therefore crucial for developing crops with lower metal content. Researchers at Nanjing Agricultural University and Yangzhou University have recently investigated the genetic mechanisms behind Cd accumulation in radish, with a focus on genes involved in transporting the metal[1]. The study centered on a gene called RsPDR12, which stands for Pleiotropic Drug Resistance 12. Pleiotropic drug resistance proteins are known to play a role in moving various substances across cell membranes, including heavy metals. The research team found that RsPDR12’s activity increased substantially when radish plants were exposed to Cd stress. To confirm its function, they tested RsPDR12 in yeast cells, discovering it could indeed transport Cd, effectively reducing its levels within the cells. Further experiments with Arabidopsis thaliana, a common model plant, showed that increasing the expression of RsPDR12 led to a decrease in Cd concentration in the roots, indicating the gene facilitates Cd removal from the plant. Interestingly, the team observed that RsPDR12 didn’t work in isolation. It also appeared to improve the plant’s ability to cope with the stress caused by Cd by enhancing the permeability of cell membranes and helping to neutralize damaging molecules called reactive oxygen species (ROS). To understand what controlled RsPDR12, the researchers identified another gene, RsWRKY15, as a key regulator. WRKY genes are a family of transcription factors – proteins that control the expression of other genes. They discovered that RsWRKY15 binds directly to the RsPDR12 gene’s promoter region, effectively turning it on and increasing its activity. Like RsPDR12, RsWRKY15’s expression also increased significantly when radish plants were exposed to Cd stress. This suggests a direct link between Cd exposure, RsWRKY15 activation, and subsequent RsPDR12 expression. Further validation came from experiments where RsWRKY15 was overexpressed in radish and Nicotiana benthamiana (tobacco) plants. The results showed that increasing RsWRKY15 levels mitigated oxidative damage – the damage caused by ROS – and reduced Cd concentration in the roots of both species. These findings build upon previous research into plant responses to heavy metal stress. For example, studies on soybean have identified WRKY transcription factors involved in Cd tolerance, demonstrating that these genes play a broad role in metal detoxification[2]. The GmWRKY142 gene in soybean, similarly to RsWRKY15 in radish, was found to activate genes responsible for decreasing Cd uptake, highlighting a common regulatory mechanism across different plant species. The current study expands on this knowledge by identifying a specific PDR gene, RsPDR12, as a direct target of RsWRKY15, forming a clear regulatory network. Furthermore, the role of ABC transporters in cesium uptake, independent of potassium transport, as highlighted in earlier research[3], provides a context for understanding the specificity of metal transport mechanisms. While this study focuses on Cd and PDR proteins, it demonstrates the complex interplay of genes involved in metal homeostasis and detoxification. The researchers also observed that the activation of protective enzyme systems, similar to what was seen in Chrysanthemum white rust resistance[4], was a key component of the radish’s response to Cd stress. The discovery of the RsWRKY15–RsPDR12 regulatory network provides valuable insights into the molecular mechanisms governing Cd accumulation in radish. This knowledge can be applied to breeding programs aimed at developing radish cultivars with lower Cd content, ultimately improving food safety and quality.

AgricultureBiochemPlant Science

References

Main Study

1) RsWRKY15–RsPDR12 module regulates Cd uptake and accumulation by promoting Cd efflux in radish (Raphanus sativus L.)

Published 12th February, 2026

https://doi.org/10.1186/s43897-025-00195-7

Related Studies

2) Transcription Factor GmWRKY142 Confers Cadmium Resistance by Up-Regulating the Cadmium Tolerance 1-Like Genes.

https://doi.org/10.3389/fpls.2020.00724

3) ATP binding cassette proteins ABCG37 and ABCG33 function as potassium-independent cesium uptake carriers in Arabidopsis roots.

https://doi.org/10.1016/j.molp.2021.02.002

4) Physiological response of CmWRKY15-1 to chrysanthemum white rust based on TRV-VIGS.

https://doi.org/10.3389/fpls.2023.1140596


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