Selenium’s Role in Plant Secondary Metabolism: Regulation and Mechanistic Insights

Selenium (Se) is an indispensable trace element for humans and other animals. Various studies have demonstrated the beneficial effects of Se on plants, including the promotion of growth, accumulation of secondary metabolites, and enhancement of antioxidant capacity, thereby improving plant stress resistance. Consequently, Se biofortification has emerged as an effective strategy to elevate Se content and nutritional quality in plants, attracting widespread attention. The mechanism of selenium (Se) at the plant secondary metabolic level has not yet been fully elucidated, and it remains an unanswered question as to how selenium affects plant secondary metabolic pathways and how these metabolic pathways respond to selenium biofortification. Although it has been shown that selenium can affect the antioxidant system and defense mechanisms in plants, detailed mechanisms of selenium’s action on plant secondary metabolic pathways, including its effects on specific metabolic enzymes and regulatory genes, still need to be revealed by further in-depth studies. The present study aims to elucidate the mechanisms of Se absorption, transport, and metabolism in plants under Se-rich conditions and to investigate the impact of various Se biofortification methods on the content of plant secondary metabolites. By integrating existing research progress, this paper will delve into the potential molecular regulatory mechanisms of Se on plant secondary metabolism, aiming to unravel the interplay between Se and plant secondary metabolism. This study provides a novel perspective and direction for future research on plant secondary metabolism and the biological utilization of Se.