Selenium Bioavailability and Accumulation in Plant Systems

Selenium is a trace element of dual importance, acting as an essential micronutrient in human and animal health yet posing toxicity risks at elevated levels. Plants serve as the principal dietary source of selenium, acquiring it from soils in inorganic forms—predominantly selenate (SeO₄²⁻) under oxidising conditions and selenite (SeO₃²⁻) in reduced or waterlogged soils. Uptake occurs via transporters originally evolved for sulphate, phosphate or silicon, followed by incorporation into organic metabolites such as selenocysteine and selenomethionine. The distribution of selenium within the plant—from root absorption to shoot translocation and seed loading—is governed by transporter specificity, soil chemistry (pH, redox potential) and interactions with nutrients (sulphur, phosphorus, nitrogen) and soil microbiota. Certain species, known as hyperaccumulators, can concentrate selenium to levels hundreds of times greater than those in surrounding soils, offering models for biofortification and phytoremediation. Agronomic strategies—including soil and foliar fertilisation, microbial inoculation and genetic selection—are being developed to optimise selenium content in edible tissues while avoiding phytotoxic thresholds. The global significance of this research spans crop improvement for selenium-deficient regions, management of selenium-rich waste streams and mitigation of environmental selenium contamination, all underpinned by advances in molecular biology, soil science and plant physiology.

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Selenium Bioavailability and Accumulation in Plant Systems publication trend

The graph below shows the total number of articles in selenium bioavailability and accumulation in plant systems across all publications each year (not limited to Nature Index journals).

Technical terms

Selenate: The oxidised inorganic form of selenium (SeO₄²⁻) readily taken up by plants via sulphate transporters.

Selenite: A reduced inorganic form of selenium (SeO₃²⁻) absorbed through phosphate or silicon transport pathways, especially under anaerobic soil conditions.

Biofortification: The process of increasing the nutrient content of edible plant parts through breeding, genetic engineering or agronomic practices.

Hyperaccumulator: A plant species capable of concentrating exceptionally high levels of a specific element, such as selenium, without suffering toxicity.

Speciation: The chemical form or oxidation state of an element, which determines its solubility, mobility and biological activity in soil–plant systems.

References

1. An Overview of Selenium Uptake, Metabolism, and Toxicity in Plants. Frontiers in Plant Science (2017).
2. Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review. Nutrients (2015).
3. OsPT2, a phosphate transporter, is involved in the active uptake of selenite in rice. New Phytologist (2013).
4. Involvement of Silicon Influx Transporter OsNIP2;1 in Selenite Uptake in Rice. Plant Physiology (2010).
5. Transporters in plant sulfur metabolism. Frontiers in Plant Science (2014).
6. Biofortification and phytoremediation of selenium in China. Frontiers in Plant Science (2015).
7. Selenium Biofortification: Roles, Mechanisms, Responses and Prospects. Molecules (2021).
8. Selenium Biofortification and Interaction With Other Elements in Plants: A Review. Frontiers in Plant Science (2020).
9. Current Knowledge on Selenium Biofortification to Improve the Nutraceutical Profile of Food: A Comprehensive Review. Journal of Agricultural and Food Chemistry (2020).