1Selenium supply alters the subcellular distribution and chemical forms of cadmium and the expression of transporter genes involved in cadmium uptake and translocation in winter wheat (Triticum aestivum)

Jiaojiao Zhu,Chang Li,Peng Zhao,Yi Wang,Shiyu Qin,Huazhong Shi,Zhaojun Nie,Hongen Liu,Xiaoming Qin

doi:10.1186/s12870-020-02763-z

Jiaojiao Zhu, Chang Li + Show 7 more

Open Access

https://doi.org/10.1186/s12870-020-02763-z

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Abstract

BackgroundCadmium (Cd) accumulation in crops affects the yield and quality of crops and harms human health. The application of selenium (Se) can reduce the absorption and transport of Cd in winter wheat.ResultsThe results showed that increasing Se supply significantly decreased Cd concentration and accumulation in the shoot and root of winter wheat and the root-to-shoot translocation of Cd. Se application increased the root length, surface area and root volume but decreased the average root diameter. Increasing Se supply significantly decreased Cd concentration in the cell wall, soluble fraction and cell organelles in root and shoot. An increase in Se supply inhibited Cd distribution in the organelles of shoot and root but enhanced Cd distribution in the soluble fraction of shoot and the cell wall of root. The Se supply also decreased the proportion of active Cd (ethanol-extractable (FE) Cd and deionized water-extractable (FW) Cd) in root. In addition, the expression of TaNramp5-a, TaNramp5-b, TaHMA3-a, TaHMA3-b and TaHMA2 significantly increased with increasing Cd concentration in root, and the expression of TaNramp5-a, TaNramp5-b and TaHMA2 in root was downregulated by increasing Se supply, regardless of Se supply or Cd stress. The expression of TaHMA3-b in root was significantly downregulated by 10 μM Se at both the 5 μM and 25 μM Cd level but upregulated by 5 μM Se at the 25 μM Cd level. The expression of TaNramp5-a, TaNramp5-b, TaHMA3-a, TaHMA3-b and TaHMA2 in shoot was downregulated by increasing Se supply at 5 μM Cd level, and 5 μM Se upregulated the expression of those genes in shoot at 25 μM Cd level.ConclusionsThe results confirm that Se application limits Cd accumulation in wheat by regulating the subcellular distribution and chemical forms of Cd in winter wheat tissues, as well as the expression of TaNramp5-a, TaNramp5-b and TaHMA2 in root.

Highlights

Cadmium (Cd) accumulation in crops affects the yield and quality of crops and harms human health
In the Se0 treatment, the Cd concentration in the shoot and root was significantly increased by increasing the Cd stress level; in the Se5 and Se10 treatments, the Cd concentration in the root was significantly increased by increasing the Cd stress level
Our results showed that Se alleviates the toxic effects of Cd on winter wheat root growth, especially under conditions of low Cd stress, showing increased root length, root surface area, and root volume and decreased root diameter with Se application (Fig. 4)

Summary

Introduction

Cadmium (Cd) accumulation in crops affects the yield and quality of crops and harms human health. Cadmium (Cd) is one of the most dangerous heavy metals due to its detrimental effects on agricultural soil and potential harm to human health [1]. Cd can harm human health through the enrichment effect of the food chain. Cdpolluted wheat accumulation in humans may cause many diseases, such as anemia, osteoporosis, kidney damage and hypertension [3]. It has become an urgent public health problem to reduce the accumulation of Cd in wheat and maintain food safety [4]

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