Licochalcone A(LCA)is a characteristic compound in licorice Glycyrrhiza inflata and is widely utilized in pharmaceutical and cosmetic industries.However,the biosynthetic pathway and regulatory mechanisms of LCA remain...Licochalcone A(LCA)is a characteristic compound in licorice Glycyrrhiza inflata and is widely utilized in pharmaceutical and cosmetic industries.However,the biosynthetic pathway and regulatory mechanisms of LCA remain poorly understood.In this study,we first found the accumulation of LCA is induced by methyl jasmonate(MeJA).Given that MYB transcriptional factors are well-documented as key regulators of flavonoid biosynthesis,we identified a total of 147 GiR2R3-MYB genes in G.inflata,which were classified into 28 subgroups.The chromosome distributions,sequence characteristics,gene structures,duplication events and cis-acting elements were also investigated.Through integrated analysis of GiR2R3-MYBs expression patterns across different tissues and under MeJA treatment,along with phylogenetic relationship,we identified GiMYB76—a MeJA-inducible MYB transcription factor—as a potential regulator of LCA accumulation.Functional validation showed that transgenic hairy roots overexpressing GiMYB76 exhibited a significant increase in LCA content.DAP-seq analysis of GiMYB76 revealed potential target genes involved in flavonoid biosynthesis regulation.Subsequent promoter activity assay verified that GiMYB76 can bind to the promoter and activate the expression of GiCHS4.Consistently,overexpression of GiCHS4 in G.inflata hairy roots also significantly enhanced LCA production.This study not only clarifies that GiMYB76 transcriptionally activated GiCHS4 to promote LCA biosynthesis but also provides valuable insights for basic research on licorice and the development of related industries.展开更多
Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the bi...Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the biosynthetic pathway of saikosaponins,we identified two cytochrome P450 monooxygenases,CYP716A41 and CYP716Y4,in Bupleurum chinense.These enzymes catalyze the C-28 oxidation and C-16 hydroxylation of oleanane-type triterpene skeletons,respectively.The catalytic efficiency of CYP716A41 from a southern B.chinense variety was significantly higher than that from a northern variety.Molecular docking and mutagenesis experiments revealed that amino acid residues at sites 9 and 35 may contribute to this difference in catalytic efficiency.Additionally,under cold stress,the expression levels of both CYP450 genes and the saikosaponin contents in the leaves of southern varieties were significantly higher compared to those in northern varieties.The variation in the catalytic efficiency of CYP716A41 and the differential expression of the two CYP450 genes under cold stress during winter are associated with the differences in saikosaponin biosynthesis in the leaves of southern and northern B.chinense varieties.This is consistent with the distinct medicinal usage practices observed between southern and northern China.展开更多
基金supported by the Guangdong Basic and Applied Basic Research Foundation (2025A1515012679)Open Fund of Shanghai Key Laboratory of Plant Functional Genomics and Resources (PFGR202502)
文摘Licochalcone A(LCA)is a characteristic compound in licorice Glycyrrhiza inflata and is widely utilized in pharmaceutical and cosmetic industries.However,the biosynthetic pathway and regulatory mechanisms of LCA remain poorly understood.In this study,we first found the accumulation of LCA is induced by methyl jasmonate(MeJA).Given that MYB transcriptional factors are well-documented as key regulators of flavonoid biosynthesis,we identified a total of 147 GiR2R3-MYB genes in G.inflata,which were classified into 28 subgroups.The chromosome distributions,sequence characteristics,gene structures,duplication events and cis-acting elements were also investigated.Through integrated analysis of GiR2R3-MYBs expression patterns across different tissues and under MeJA treatment,along with phylogenetic relationship,we identified GiMYB76—a MeJA-inducible MYB transcription factor—as a potential regulator of LCA accumulation.Functional validation showed that transgenic hairy roots overexpressing GiMYB76 exhibited a significant increase in LCA content.DAP-seq analysis of GiMYB76 revealed potential target genes involved in flavonoid biosynthesis regulation.Subsequent promoter activity assay verified that GiMYB76 can bind to the promoter and activate the expression of GiCHS4.Consistently,overexpression of GiCHS4 in G.inflata hairy roots also significantly enhanced LCA production.This study not only clarifies that GiMYB76 transcriptionally activated GiCHS4 to promote LCA biosynthesis but also provides valuable insights for basic research on licorice and the development of related industries.
基金supported by CARS(CARS-21),the CAMS Innovation Fund for Medical Sciences(2021-I2M-1-032)the Science and Technology Department of Xizang(XZ202401ZY0020)+2 种基金the Science and Technology Department of Sichuan Province(2023YFH0044,2023YFH0018)the Sichuan Province Science Foundation for Distinguished Young Scholars(2022JDJQ0006)the Doctoral Fund of Southwest University of Science and Technology(19ZX7117,21ZX7116).
文摘Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the biosynthetic pathway of saikosaponins,we identified two cytochrome P450 monooxygenases,CYP716A41 and CYP716Y4,in Bupleurum chinense.These enzymes catalyze the C-28 oxidation and C-16 hydroxylation of oleanane-type triterpene skeletons,respectively.The catalytic efficiency of CYP716A41 from a southern B.chinense variety was significantly higher than that from a northern variety.Molecular docking and mutagenesis experiments revealed that amino acid residues at sites 9 and 35 may contribute to this difference in catalytic efficiency.Additionally,under cold stress,the expression levels of both CYP450 genes and the saikosaponin contents in the leaves of southern varieties were significantly higher compared to those in northern varieties.The variation in the catalytic efficiency of CYP716A41 and the differential expression of the two CYP450 genes under cold stress during winter are associated with the differences in saikosaponin biosynthesis in the leaves of southern and northern B.chinense varieties.This is consistent with the distinct medicinal usage practices observed between southern and northern China.
