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
Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig ...Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig production.R2R3-MYB transcription factors have promotive or repressive regulatory roles in plant anthocyanin biosynthesis.In this study,113 R2R3-MYB genes were identified in Ficus carica,3 of which were assigned to the S4 subfamily of flavonoid-biosynthesis repressors.FcMYB57 was further recruited as a candidate anthocyaninbiosynthesis repressor based on its sequence features and expression,which was significantly negatively correlated with that of anthocyanin-biosynthesis structural genes.Transient overexpression of FcMYB57 in strawberry totally inhibited fruit pigmentation and significantly increased fruit firmness.The metabolomic analysis confirmed a significant reduction in the contents of cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside,as well as other flavonoids,and transmission electron microscopy revealed an increment in cell-wall thickness.Transcriptome analysis showed downregulation of anthocyanin-biosynthesis structural genes and upregulation of genes related to xylan synthesis.Yeast one-hybrid and dual luciferase assays demonstrated a negative regulatory effect of FcMYB57 on the promoter of FcUFGT3(UDP glucose-flavonoid 3-O-glcosyl-transferase).Yeast two-hybrid assay showed that FcMYB57 does not interact with FcbHLH42,3,14,MYC2,or FcTTG1,all of which have a previously identified or predicted role in flavonoid biosynthesis,however,interaction was detected with FcTPL(Topless),suggesting that FcMYB57 serves as an active repressor of anthocyanin biosynthesis.This is the first identification of an anthocyaninbiosynthesis repressor in fig,with a possible role in fig fruit quality.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 the key research project for fig development of Weiyuan County(Grant No.1002-69199007),China.
文摘Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig production.R2R3-MYB transcription factors have promotive or repressive regulatory roles in plant anthocyanin biosynthesis.In this study,113 R2R3-MYB genes were identified in Ficus carica,3 of which were assigned to the S4 subfamily of flavonoid-biosynthesis repressors.FcMYB57 was further recruited as a candidate anthocyaninbiosynthesis repressor based on its sequence features and expression,which was significantly negatively correlated with that of anthocyanin-biosynthesis structural genes.Transient overexpression of FcMYB57 in strawberry totally inhibited fruit pigmentation and significantly increased fruit firmness.The metabolomic analysis confirmed a significant reduction in the contents of cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside,as well as other flavonoids,and transmission electron microscopy revealed an increment in cell-wall thickness.Transcriptome analysis showed downregulation of anthocyanin-biosynthesis structural genes and upregulation of genes related to xylan synthesis.Yeast one-hybrid and dual luciferase assays demonstrated a negative regulatory effect of FcMYB57 on the promoter of FcUFGT3(UDP glucose-flavonoid 3-O-glcosyl-transferase).Yeast two-hybrid assay showed that FcMYB57 does not interact with FcbHLH42,3,14,MYC2,or FcTTG1,all of which have a previously identified or predicted role in flavonoid biosynthesis,however,interaction was detected with FcTPL(Topless),suggesting that FcMYB57 serves as an active repressor of anthocyanin biosynthesis.This is the first identification of an anthocyaninbiosynthesis repressor in fig,with a possible role in fig fruit quality.
