Broussonetia papyrifera (L.) L’Hér. ex Vent., a dioecious tree species that belongs to the Moraceae family, is a perennial plant found extensively throughout China. Its leaves are rich in essential trace elements such as copper, molybdenum, manganese, and iron, as well as various biologically active compounds, including amino acids, polysaccharides, proteins, as well as flavonoids, phenylpropanoids, and other polyphenolic compounds. These compounds exhibit significant pharmacological effects, such as antioxidant, lipid-lowering, heat-clearing, detoxifying, blood-cooling, diuretic, and immunomodulatory activities. In recent years, B. papyrifera has gained attention for its medicinal potential; however, breeding efforts, especially those aimed at increasing the flavonoid content, have lagged. This study reviews the progress in research on the active medicinal ingredients of B. papyrifera, with a focus on identification methods, classification criteria, and enrichment technologies for its medicinal components. The biosynthesis of structural genes and transcription factors in flavonoids has been investigated in B. papyrifera. The pharmacological effects of the secondary metabolites of B. papyrifera were systematically examined, aiming to offer strategies for enhancing the flavonoid content and promoting its medicinal value.

Broussonetia papyrifera has strong adaptability and exhibits a strong ability to accumulate selenium. Its leaves are rich in crude protein, amino acids, and minerals, making them high-quality feed materials. To improve the selenium-enriched ability of B. papyrifera and promote the development of selenium-enriched agricultural products, we screened and identified the sulfate transporters associated with selenium absorption in B. papyrifera. By treating the leaves of B. papyrifera with different concentrations of sodium selenate and analyzing the correlation between gene expression and selenium content, we identified BpSULTR3;1 and BpSULTR3;4, which may be involved in selenium absorption and transport in B. papyrifera. We further validated the functions of BpSULTR3;1 and BpSULTR3;4 through transgenic experiments in Arabidopsis thaliana. The results showed that overexpressing BpSULTR3;1 significantly increased the total selenium content in A. thaliana, up to 2.31 times, and also increased the contents of three forms of organic selenium (SeCys₂, MeSeCys and SeMet) in transgenic A. thaliana. These findings provide solid theoretical support for improving B. papyrifera’s selenium enrichment ability through genetic improvement.