Salvia miltiorrhiza is a medicinal plant widely used in the treatment of cardiovascular and cerebrovascular diseases. Hydrophilic phenolic acids, including rosmarinic acid(RA) and lithospermic acid B(LAB), are its pri...Salvia miltiorrhiza is a medicinal plant widely used in the treatment of cardiovascular and cerebrovascular diseases. Hydrophilic phenolic acids, including rosmarinic acid(RA) and lithospermic acid B(LAB), are its primary medicinal ingredients. However, the biosynthetic pathway of RA and LAB in S. miltiorrhiza is still poorly understood. In the present study, we accomplished the isolation and characterization of a novel S. miltiorrhiza Hydroxyphenylpyruvate reductase(HPPR) gene, Sm HPPR, which plays an important role in the biosynthesis of RA. Sm HPPR contained a putative catalytic domain and a NAD(P)H-binding motif. The recombinant Sm HPPR enzyme exhibited high HPPR activity, converting 4-hydroxyphenylpyruvic acid(p HPP) to 4-hydroxyphenyllactic acid(p HPL), and exhibited the highest affinity for substrate 4-hydroxyphenylpyruvate. Sm HPPR expression could be induced by various treatments, including SA, GA_3, Me JA and Ag^+, and the changes in Sm HPPR activity were correlated well with hydrophilic phenolic acid accumulation. Sm HPPR was localized in cytoplasm, most likely close to the cytosolic NADPH-dependent hydroxypyruvate reductase active in photorespiration. In addition, the transgenic S. miltiorrhiza hairy roots overexpressing Sm HPPR exhibited up to 10-fold increases in the products of hydrophilic phenolic acid pathway. In conclusion, our findings provide a new insight into the synthesis of active pharmaceutical compounds at molecular level.展开更多
基金supported by the National Natural Science Foundation of China(Nos.81673529,81325024,and 31300159)Shanghai Science and Technology Development Funds(Nos.15391900500 and 14QB1402700)National Science and Technology Major Project of China(No.2017ZX09101002-003-002)
文摘Salvia miltiorrhiza is a medicinal plant widely used in the treatment of cardiovascular and cerebrovascular diseases. Hydrophilic phenolic acids, including rosmarinic acid(RA) and lithospermic acid B(LAB), are its primary medicinal ingredients. However, the biosynthetic pathway of RA and LAB in S. miltiorrhiza is still poorly understood. In the present study, we accomplished the isolation and characterization of a novel S. miltiorrhiza Hydroxyphenylpyruvate reductase(HPPR) gene, Sm HPPR, which plays an important role in the biosynthesis of RA. Sm HPPR contained a putative catalytic domain and a NAD(P)H-binding motif. The recombinant Sm HPPR enzyme exhibited high HPPR activity, converting 4-hydroxyphenylpyruvic acid(p HPP) to 4-hydroxyphenyllactic acid(p HPL), and exhibited the highest affinity for substrate 4-hydroxyphenylpyruvate. Sm HPPR expression could be induced by various treatments, including SA, GA_3, Me JA and Ag^+, and the changes in Sm HPPR activity were correlated well with hydrophilic phenolic acid accumulation. Sm HPPR was localized in cytoplasm, most likely close to the cytosolic NADPH-dependent hydroxypyruvate reductase active in photorespiration. In addition, the transgenic S. miltiorrhiza hairy roots overexpressing Sm HPPR exhibited up to 10-fold increases in the products of hydrophilic phenolic acid pathway. In conclusion, our findings provide a new insight into the synthesis of active pharmaceutical compounds at molecular level.
