Objective:Salvia miltiorrhiza is a valuable herbal medicine with tanshinone and phenolic acid as the main biological active ingredients.The biosynthetic regulation of these bioactive compounds is controlled by a set o...Objective:Salvia miltiorrhiza is a valuable herbal medicine with tanshinone and phenolic acid as the main biological active ingredients.The biosynthetic regulation of these bioactive compounds is controlled by a set of transcription factors(TFs).The basic helix-loop-helix(bHLH)transcription factor plays an important role in various physiological and biochemical processes in plants.However,research on bHLH TFs regulating phenolic acid or tanshinone biosynthesis in S.miltiorrhiza is limited.Methods:qRT-PCR was used for gene expression analysis.The subcellular localization of SmbHLH92 was detected by SmbHLHg2-GFP transient transformation into tobacco leaves,and its fluorescence was observed using a confocal laser scanning microscope.The transcriptional activity of SmbHLH92 was confirmed in the AH109 yeast strain.RNA interference hairy roots of SmbHLH92-RNAi transgenic lines were obtained through Agrobacterium-mediated genetic transformation.Ultra performance liquid chromatography(UPLC)was used to detect the changes of phenolic acids and tanshinones.Results:SmbHLH92 is a bHLH transcription factor that is highly expressed in the root and phloem of S.miltiorrhiza.The subcellular localization and transcriptional activity of SmbHLH92 indicated that SmbHLH92 was located in the nucleus and may be a transcription factor.RNA interference(RNAi)of SmbHLH92 in hairy roots of S.miltiorrhiza significantly increased the accumulation of phenolic acid and tanshinone.Quantitative RT-PCR(RT-qPCR)analysis showed the transcription level of genes encoding the key enzymes involved in the phenolic acid and tanshinone biosynthetic pathways was increased in the hairy roots of the SmbHLH92-RNAi transgenic line,comparing with the control line.Conclusion:These data indicate that SmbHLH92 is a negative regulator involved in the regulation of phenolic acid and tanshinone biosynthesis in S.miltiorrhiza.展开更多
A novel semisolid stirring and rheo-rolling process for preparing Mg-3Sn-1Mn-3SiC （wt%） composite strips was proposed, and the effects of process parameters of semisolid stirring on microstructures of Mg-3Sn-1Mn-3S...A novel semisolid stirring and rheo-rolling process for preparing Mg-3Sn-1Mn-3SiC （wt%） composite strips was proposed, and the effects of process parameters of semisolid stirring on microstructures of Mg-3Sn-1Mn-3SiC （wt%） composite strips were investigated. The average grain size and roundness decrease, and the distribution of SiC becomes more homogeneous with the decrease in stirring temperature and the increase in the stirring speed. When the stirring time is increased, the distribution of SiC particles tends to be homogeneous, and the average grain diameter and roundness of α- Mg grain decrease. Under the following process parameters： the stirring temperature at 640 ℃, the stirring speed at 1100 rpm, the stirring time at 30 min and the roll speed at 0.2 m/s, Mg-3Sn-1Mn-3SiC （wt%） strip with a cross-sectional size of 4 mm × 160 mm was prepared. The ultimate tensile strength and elongation of Mg-3Sn-1Mn-3SiC （wt%） composite strip reached 226 ± 6 MPa and （7.4 ± 0.2）%, which are obviously improved in comparison with Mg-3Sn-1Mn （wt%）.展开更多
基金This work was supported by the National Natural Science Foundation(Grant No.31570302,81973422)Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(CIFMS,2016-I2M-3-016).
文摘Objective:Salvia miltiorrhiza is a valuable herbal medicine with tanshinone and phenolic acid as the main biological active ingredients.The biosynthetic regulation of these bioactive compounds is controlled by a set of transcription factors(TFs).The basic helix-loop-helix(bHLH)transcription factor plays an important role in various physiological and biochemical processes in plants.However,research on bHLH TFs regulating phenolic acid or tanshinone biosynthesis in S.miltiorrhiza is limited.Methods:qRT-PCR was used for gene expression analysis.The subcellular localization of SmbHLH92 was detected by SmbHLHg2-GFP transient transformation into tobacco leaves,and its fluorescence was observed using a confocal laser scanning microscope.The transcriptional activity of SmbHLH92 was confirmed in the AH109 yeast strain.RNA interference hairy roots of SmbHLH92-RNAi transgenic lines were obtained through Agrobacterium-mediated genetic transformation.Ultra performance liquid chromatography(UPLC)was used to detect the changes of phenolic acids and tanshinones.Results:SmbHLH92 is a bHLH transcription factor that is highly expressed in the root and phloem of S.miltiorrhiza.The subcellular localization and transcriptional activity of SmbHLH92 indicated that SmbHLH92 was located in the nucleus and may be a transcription factor.RNA interference(RNAi)of SmbHLH92 in hairy roots of S.miltiorrhiza significantly increased the accumulation of phenolic acid and tanshinone.Quantitative RT-PCR(RT-qPCR)analysis showed the transcription level of genes encoding the key enzymes involved in the phenolic acid and tanshinone biosynthetic pathways was increased in the hairy roots of the SmbHLH92-RNAi transgenic line,comparing with the control line.Conclusion:These data indicate that SmbHLH92 is a negative regulator involved in the regulation of phenolic acid and tanshinone biosynthesis in S.miltiorrhiza.
基金financially supported by The National Natural Science Foundation of China (Nos. 51604246 and 51674077)Shanxi Province Science Foundation for Youths
文摘A novel semisolid stirring and rheo-rolling process for preparing Mg-3Sn-1Mn-3SiC （wt%） composite strips was proposed, and the effects of process parameters of semisolid stirring on microstructures of Mg-3Sn-1Mn-3SiC （wt%） composite strips were investigated. The average grain size and roundness decrease, and the distribution of SiC becomes more homogeneous with the decrease in stirring temperature and the increase in the stirring speed. When the stirring time is increased, the distribution of SiC particles tends to be homogeneous, and the average grain diameter and roundness of α- Mg grain decrease. Under the following process parameters： the stirring temperature at 640 ℃, the stirring speed at 1100 rpm, the stirring time at 30 min and the roll speed at 0.2 m/s, Mg-3Sn-1Mn-3SiC （wt%） strip with a cross-sectional size of 4 mm × 160 mm was prepared. The ultimate tensile strength and elongation of Mg-3Sn-1Mn-3SiC （wt%） composite strip reached 226 ± 6 MPa and （7.4 ± 0.2）%, which are obviously improved in comparison with Mg-3Sn-1Mn （wt%）.
