Saponins are the main triterpenoid ingredients from Panax notoginseng,a well-known Chinese medicine,and are important sources for producing drugs to prevent and treat cerebrovascular and cardiovascular diseases.Howeve...Saponins are the main triterpenoid ingredients from Panax notoginseng,a well-known Chinese medicine,and are important sources for producing drugs to prevent and treat cerebrovascular and cardiovascular diseases.However,the transcriptional regulatory network of saponin biosynthesis in P.notoginseng is largely unknown.In the present study we demonstrated that one R2R3-MYB transcription factor,designated PnMYB4,acts as a repressor of saponin accumulation.Suppression of PnMYB4 in P.notoginseng calli significantly increased the saponin content and the expression level of saponin biosynthetic genes.PnMYB4 directly bound to the promoters of key saponin biosynthetic genes,including PnSS,PnSE,and PnDS,to repress saponin accumulation.PnMYB4 and the activator PnMYB1 could inter-acted with PnbHLH,which is a positive regulator of saponin biosynthesis,to modulate the biosynthesis of saponin.PnMYB4 competed with PnMYB1 for binding to PnbHLH,repressing activation of the promoters of saponin structural genes induced by the PnMYB1-PnbHLH complex.Our study reveals that a complex regulatory module of saponin biosynthesis is associated with positive and negative MYB transcriptional regulators and provides a theoretical basis for improving the content of saponins and efficacy of P.notoginseng.展开更多
In this research a novel electrochemical system using dual boron-doped diamond (BDD) electrodes as the anode and cathode, for the first time, has been developed for CO_2 conversion and wastewater treatment in a synerg...In this research a novel electrochemical system using dual boron-doped diamond (BDD) electrodes as the anode and cathode, for the first time, has been developed for CO_2 conversion and wastewater treatment in a synergetic and simultaneous process. On the BDD cathode CO_2 is converted into formaldehyde while in the anodic side organic wastes are decomposed on the BDD anode. Interestingly, when potassium hydrogen phthalate (KHP) was used as the organic model to be degraded in the anodic side, a higher efficiency of formaldehyde generation from CO_2 was observed on the BDD cathode. The enhanced effect of formaldehyde formation in the presence of KHP oxidation suggests that this novel electrochemical system can combine conversion of CO_2 to the form of high-value chemicals and wastewater purification in a simultaneous and harmonious process.展开更多
基金This study was supported by Beijing Science and Technology Planning Project(Z201100005420005,China).
文摘Saponins are the main triterpenoid ingredients from Panax notoginseng,a well-known Chinese medicine,and are important sources for producing drugs to prevent and treat cerebrovascular and cardiovascular diseases.However,the transcriptional regulatory network of saponin biosynthesis in P.notoginseng is largely unknown.In the present study we demonstrated that one R2R3-MYB transcription factor,designated PnMYB4,acts as a repressor of saponin accumulation.Suppression of PnMYB4 in P.notoginseng calli significantly increased the saponin content and the expression level of saponin biosynthetic genes.PnMYB4 directly bound to the promoters of key saponin biosynthetic genes,including PnSS,PnSE,and PnDS,to repress saponin accumulation.PnMYB4 and the activator PnMYB1 could inter-acted with PnbHLH,which is a positive regulator of saponin biosynthesis,to modulate the biosynthesis of saponin.PnMYB4 competed with PnMYB1 for binding to PnbHLH,repressing activation of the promoters of saponin structural genes induced by the PnMYB1-PnbHLH complex.Our study reveals that a complex regulatory module of saponin biosynthesis is associated with positive and negative MYB transcriptional regulators and provides a theoretical basis for improving the content of saponins and efficacy of P.notoginseng.
基金supported by the scholarship under the Sichuan University Scholarship Fund allocated by the Ministry of Education to pursue his research as a visiting scholar overseasthe Experimental Technology Project(No. 20170209)of Sichuan University
文摘In this research a novel electrochemical system using dual boron-doped diamond (BDD) electrodes as the anode and cathode, for the first time, has been developed for CO_2 conversion and wastewater treatment in a synergetic and simultaneous process. On the BDD cathode CO_2 is converted into formaldehyde while in the anodic side organic wastes are decomposed on the BDD anode. Interestingly, when potassium hydrogen phthalate (KHP) was used as the organic model to be degraded in the anodic side, a higher efficiency of formaldehyde generation from CO_2 was observed on the BDD cathode. The enhanced effect of formaldehyde formation in the presence of KHP oxidation suggests that this novel electrochemical system can combine conversion of CO_2 to the form of high-value chemicals and wastewater purification in a simultaneous and harmonious process.
