Selenium Exerts an Intriguing Alteration of Primary and Secondary Plant Metabolites: Advances, Challenges, and Prospects

Selenium (Se) is not yet conclusively classified as an essential nutrient required for plant growth. However, much attention has been devoted to its important role in human health since Se enrichment affects the production of primary and secondary metabolites. A strong link between low levels of Se and cancer and cardiac diseases has been proven. Thus, Se enrichment of crops has been established as a pioneering strategy to enhance Se intake by animals and humans. It has been proven that Se biofortification through a foliar application or in the growth medium has increased Se levels in plant tissues without loss of productivity or qualitative properties. However, to achieve the desirable level of Se and promote human health, Se accumulation in plants should be quantified and balanced because Se enrichment may affect their nutrient balance. This timely review provides a broad overview of the metabolic changes induced in plants by Se enrichment.Additionally, it highlights the contrasting effects of Se biofortification on the up-and-down-regulation of several secondary metabolites including phenolics, flavonoids, and their derivatives, as well as glucosinolates.

Automated summary

Selenium's classification as an essential nutrient for plant growth is still uncertain, but its role in human health is important due to its impact on the production of primary and secondary metabolites. Low levels of selenium have been linked to cancer and cardiac diseases. Enriching crops with selenium has been established as a pioneering strategy to increase selenium intake in animals and humans. Studies have shown that selenium biofortification can increase selenium levels in plant tissues without affecting productivity or quality. However, the accumulation of selenium in plants needs to be quantified and balanced, as it may affect nutrient balance. This timely review provides an overview of the metabolic changes induced in plants by selenium enrichment, and highlights the contrasting effects on various secondary metabolites.