Identification of Sulfate Transporter Genes in Broussonetia papyrifera and Analysis of Their Functions in Regulating...

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.