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.

Cadmium (Cd) is a common agricultural soil pollutant, which does serious harm to the environment and the human body. In this study, Brassica juncea was treated with different concentrations of CdCl₂ and Na₂SeO₃. Then, physiological indexes and transcriptome were measured to reveal the mechanisms by which Se reduces the inhibition and toxicity of Cd in B. juncea. The results showed that Se alleviated the inhibitive Cd effects on seedling biomass, root length, and chlorophyll, and promoted the adsorption of Cd by pectin and lignin in the root cell wall (CW). Se also alleviated the oxidative stress induced by Cd, and reduced the content of MDA in cells. As a result, SeCys and SeMet alleviated the transport of Cd to the shoots. Transcriptome data showed that the bivalent cation transporter MPP and ABCC subfamily participated in the separation of Cd in vacuoles, CAL1 was related to the chelation of Cd in the cytoplasm of cells, and ZIP transporter 4 reduced the transport of Cd to the shoots. These results indicated that Se alleviated the damage of Cd in plants and decreased its transport to the shoots by improving the antioxidant system, enhancing the ability of the CW to adsorb Cd, reducing the activity of Cd transporters, and chelating Cd.

Resistant starch (RS) refers to starch varieties that resist digestion by human digestive enzymes. Owing to its distinctive physicochemical attributes and functional capabilities, RS has gained a wide range of applications as a dietary fiber and prebiotic. In terms of structure and functions, RS can be categorized into five distinct types: RS1 through RS5. These types offer dietary benefits, contributing to improved colonic health, the modulation of microbial communities, the reduction in gallstone formation, the enhancement of mineral absorption, and alterations in fat oxidation potential. From a technical standpoint, RS can be manufactured through an array of physical, enzymatic, and chemical modifications. This paper presents a comprehensive review of the existing literature, summarizing the classification, structural features, raw material origins, preparation methodologies, and functionalities of RS. Furthermore, new production technologies and applications of RS, such as 3D printing, provide valuable insights.

In the context of rapid industrialization and agricultural modernization, the issue of heavy metal (HM) pollution has surfaced as a critical concern, posing a substantial threat to human health and having a profound impact on agricultural cultivation. Selenium (Se), a beneficial micronutrient for crop growth and development, exerts numerous beneficial effects, including facilitating photosynthesis, enhancing physiological attributes, improving nutritional quality, strengthening antioxidant systems, and modulating the expression of stress-responsive genes. Notably, Se plays a pivotal role in alleviating HM stress in crops and effectively mitigating the accumulation of HMs in edible plant parts. This study investigates the physiological and molecular mechanisms underlying Se’s capacity to alleviate HM stress in crops. Additionally, we discuss the application of Se-enriched fertilizers in agricultural practices, as well as the influence of environmental factors on their effectiveness. Our objective is to contribute to sustainable agricultural development and the production of safe, high-quality agricultural products, thereby providing valuable insights for the development of Se-functional industries and guiding agricultural practices in regions affected by HM pollution.

It is an essential method for healthy Selenium (Se) supplementation to convert exogenous Se into organic Se via crops. Brassica juncea (L.) Czern (leaf mustard) was employed as plant material in this investigation and was treated with sodium selenite (Na₂SeO₃). Its physiological indicators, nutritional quality, antioxidant enzyme activity, total Se content, and Se morphology were all evaluated. The absorption, transportation, and transformation mechanisms of Se in mustard were studied using transcriptome data. The results revealed that low concentration of Se treatment promoted the growth of mustard, while high concentration Se treatment inhibited it. The concentration of 10 mg/L Na₂SeO₃ treatment had the best growth parameters for mustard. Compared to the control group, the content of vitamin C (Vc) and anthocyanins in the treatment group increased to varying degrees, while the content of flavonoids, total phenols, soluble sugar, and soluble protein increased first and then decreased. Five Se forms, Se (IV), Se (VI), selenocystine(SeCys2), selenomethionine (SeMet), and methylselenocysteine (MeSeCys), were detected in the Na₂SeO₃ treatment group, with organic Se accounting for over 95%. Na₂SeO₃ treatment can significantly reduce the accumulation of ROS in mustard plants and enhance their stress resistance. Transcriptome data and metabolite association analysis showed that PHO1-H8 promoted the absorption of Na₂SeO₃ by mustard roots, while SULTR3;3 and SULTR4;1 promoted the transport of Se from roots to the aboveground portion and chloroplasts. Se in mustard was transformed into SeMet, SeCys, MeSeCys, and selenoprotein through the action of genes such as APS, APR, and SEP1, and stored in plant leaves.

Selenium (Se) is an essential trace element for the human body, and its dietary deficiency has been a widespread issue globally. Vegetables serve as a significant source of dietary Se intake, with organic Se derived from plants being safer than inorganic Se. In the present study, Taraxacum mongolicum plants were treated with various concentrations of Na₂SeO₃. The results showed that as the concentration of Na₂SeO₃ increased, the chlorophyll content of dandelion seedlings decreased at high concentrations, and the content of soluble sugars, soluble proteins, flavonoids, total phenols, and Vc all increased. The application of Na₂SeO₃ at concentrations ranging from 0 to 4 mg/L resulted in a reduction in plant malondialdehyde content and an enhancement in the activity of antioxidant enzymes. Following the Na₂SeO₃ treatment, five Se species were identified in the seedlings, Se⁴⁺, Se⁶⁺, selenocysteine, selenomethionine, and methylselenocysteine. Notably, selenomethionine emerged as the primary organic Se species in the shoots of dandelion. Transcriptome analysis revealed that ABC11b, PTR4, MOCOS, BAK1, and CNGC1 were involved in the absorption, transport, and storage of Se in dandelion, and C7317 was involved in the scavenging of reactive oxygen species. This study complements the understanding of the possible molecular mechanisms involved in the absorption and transformation of organic Se by plants, thereby providing a theoretical foundation for the biofortification of dandelion with Se in crops.