SrUGT76G1,the most well-studied diterpene glycosyltransferase in Stevia rebaudiana,is key to the biosynthesis of economically important steviol glycosides(SGs).However,the molecular regulatory mechanism of SrUGT76G1 h...SrUGT76G1,the most well-studied diterpene glycosyltransferase in Stevia rebaudiana,is key to the biosynthesis of economically important steviol glycosides(SGs).However,the molecular regulatory mechanism of SrUGT76G1 has rarely been explored.In this study,we identified a MYB transcription factor,SrMYB1,using a yeast one-hybrid screening assay.SrMYB1 belongs to the typical R2R3-type MYB protein and is specifically localized in the nucleus with strong transactivation activity.The transcript of SrMYB1 is predominantly accumulated in flowers,but is also present at a lower level in leaves.Yeast one-hybrid and electrophoretic mobility shift assays verified that SrMYB1 binds directly to the MYB binding sites in the F4-3 fragment(+50–(–141))of the SrUGT76G1 promoter.Furthermore,we found that SrMYB1 could significantly repress the expression of SrUGT76G1 in both epidermal cells of tobacco leaves and stevia callus.Taken together,our results demonstrate that SrMYB1 is an essential upstream regulator of SrUGT76G1 and provide novel insight into the regulatory network for the SGs metabolic pathway in S.rebaudiana.展开更多
以国内首个^(76)Ge同位素分离工程的离心级联检测控制为对象,通过DCS(Distributed Control System)控制系统硬件结构和组态编程,确保了主工艺关键设备——稳旋机的安全性,实现了实时查看现场各类工艺参数、远程开关电动阀、远程调节阀...以国内首个^(76)Ge同位素分离工程的离心级联检测控制为对象,通过DCS(Distributed Control System)控制系统硬件结构和组态编程,确保了主工艺关键设备——稳旋机的安全性,实现了实时查看现场各类工艺参数、远程开关电动阀、远程调节阀门开度及远程启停真空泵等功能,有力地保障了^(76)Ge同位素生产线的安全平稳运行。展开更多
The INDO series of methods were used to optimize the structures of C n 76(-4≤n≤6) without any symmetry constriction. It was indicated that there are 30 kinds of bonds and 19 types of unique carbon atoms, but there a...The INDO series of methods were used to optimize the structures of C n 76(-4≤n≤6) without any symmetry constriction. It was indicated that there are 30 kinds of bonds and 19 types of unique carbon atoms, but there are not Jahn Teller distortion in C n 76, which is different from C n 60 and C n 70. Furthermore, the C n 76 ions are less stable than C 76. Based on the optimized geometries, the electronic spectra were calculated by INDO/SCI method. It was shown that the NIR absorptions for C n 76 singlet will appear beyond \{1 000\} nm. Electronic transition was assigned theoretically and the reason of red shift for absorption peaks of C n 76 compared with those of C 76 was discussed.展开更多
基金supported by the National Natural Science Foundation of China(31901597)the Natural Science Foundation of Jiangsu Province,China(BK20201243)。
文摘SrUGT76G1,the most well-studied diterpene glycosyltransferase in Stevia rebaudiana,is key to the biosynthesis of economically important steviol glycosides(SGs).However,the molecular regulatory mechanism of SrUGT76G1 has rarely been explored.In this study,we identified a MYB transcription factor,SrMYB1,using a yeast one-hybrid screening assay.SrMYB1 belongs to the typical R2R3-type MYB protein and is specifically localized in the nucleus with strong transactivation activity.The transcript of SrMYB1 is predominantly accumulated in flowers,but is also present at a lower level in leaves.Yeast one-hybrid and electrophoretic mobility shift assays verified that SrMYB1 binds directly to the MYB binding sites in the F4-3 fragment(+50–(–141))of the SrUGT76G1 promoter.Furthermore,we found that SrMYB1 could significantly repress the expression of SrUGT76G1 in both epidermal cells of tobacco leaves and stevia callus.Taken together,our results demonstrate that SrMYB1 is an essential upstream regulator of SrUGT76G1 and provide novel insight into the regulatory network for the SGs metabolic pathway in S.rebaudiana.
文摘以国内首个^(76)Ge同位素分离工程的离心级联检测控制为对象,通过DCS(Distributed Control System)控制系统硬件结构和组态编程,确保了主工艺关键设备——稳旋机的安全性,实现了实时查看现场各类工艺参数、远程开关电动阀、远程调节阀门开度及远程启停真空泵等功能,有力地保障了^(76)Ge同位素生产线的安全平稳运行。
文摘The INDO series of methods were used to optimize the structures of C n 76(-4≤n≤6) without any symmetry constriction. It was indicated that there are 30 kinds of bonds and 19 types of unique carbon atoms, but there are not Jahn Teller distortion in C n 76, which is different from C n 60 and C n 70. Furthermore, the C n 76 ions are less stable than C 76. Based on the optimized geometries, the electronic spectra were calculated by INDO/SCI method. It was shown that the NIR absorptions for C n 76 singlet will appear beyond \{1 000\} nm. Electronic transition was assigned theoretically and the reason of red shift for absorption peaks of C n 76 compared with those of C 76 was discussed.
