On the basis of sequences of UGPase from plants, a cDNA encoding the enzyme was isolated from the hairy root of Astragalus membranaceus (Fisch.) Bunge. The cDNA consisted of 1 831 bp and encoded a polypeptide of 4...On the basis of sequences of UGPase from plants, a cDNA encoding the enzyme was isolated from the hairy root of Astragalus membranaceus (Fisch.) Bunge. The cDNA consisted of 1 831 bp and encoded a polypeptide of 471 amino acid residues with a calculated molecular weight of 51.5 kD and a deduced isoelectric point of 6.01. Then the open read frame of the cDNA was ligated into pET28(a) + vector and expressed in E. coli BL21. SDS_PAGE showed that the expressed protein was ca. 40% in the total bacterial protein. Enzyme activity assay demonstrated that the UGPase activity in the transformed bacteria was 0.50-3.27 times higher than that of the control. Northern blotting revealed that ugp was expressed in the leaf, stem, root and hairy root of A. membranaceus , with a higher level in root and hairy root.展开更多
UDP-glucose pyrophosphorylase is an important enzyme concerned with carbohydrate metabolism in plants. Cloning of UGPase is a premise for further study on molecular level, and it is also crucial for study of carbohydr...UDP-glucose pyrophosphorylase is an important enzyme concerned with carbohydrate metabolism in plants. Cloning of UGPase is a premise for further study on molecular level, and it is also crucial for study of carbohydrate metabolism. UGPase cDNA sequence as a template, designed primer, then 3＇-untranslate region （3＇ UTR） of UGPase were amplified by 3＇-rapid amplification of cDNA ends （3＇-RACE）. The results suggested the 3＇ UTR were 243 bp, contained AATAA sequence and Poly（A）.展开更多
UGPase （UDP-glucose pyrophosphorylase）, one of the primary enzymes concerned with carbohydrate metabolism, catalyzes the formation of UDPG. By inserting the UGPase cDNA fragment cloned from Saccharum officinarum int...UGPase （UDP-glucose pyrophosphorylase）, one of the primary enzymes concerned with carbohydrate metabolism, catalyzes the formation of UDPG. By inserting the UGPase cDNA fragment cloned from Saccharum officinarum into PQE-30, the prokaryotic expression vector of PQE-UGP was successfully constructed. Then the vector plasmid of PQE-UGP was transformed into host bacteria M 15 and the expression of target gene was induced by Isopropyl β-D-1-Thiogalactopyranoside （IPTG）. The research laid foundation for study on the prokaryotic expression of UGPase.展开更多
The experiment was designed, via storing potato tubers of cv. E-Potato1 and E-Potato3 indifferent temperatures, to explore the variation patterns of reducing sugar (RS) andtotal sugar (TS) contents and enzyme activiti...The experiment was designed, via storing potato tubers of cv. E-Potato1 and E-Potato3 indifferent temperatures, to explore the variation patterns of reducing sugar (RS) andtotal sugar (TS) contents and enzyme activities that are involved in the pathway ofstarch-sugar metabolism aiming at identifying the main factors that influence the chipcolor. The results showed that low temperature in storage was a main factor thataccelerated the accumulation of RS of the stored tubers and a very significant linearrelationship existed between RS content and chip color index (CCI) of the tubers. Furtheranalysis elucidated that when tubers stored at 4℃, the activities of ADP glucosepyrophosphorylase (AGPase), UDP glucose pyrophosphorylase (UGPase) and sucrose synthase(SuSy) were negatively exponential to the RS content significantly while that of acidinvertase and alkaline invertase was significantly linear to RS content. It suggestedthat these enzymes could play main roles in the cold sweetening of potato tubers throughregulating starch-sugar metabolism.展开更多
UGPase gene related with wood cellulose synthesis was transferred into C. acuminata using the method of Agrobacte- rium-mediated genetic transformation, and an efficient transformation system was developed for C. acum...UGPase gene related with wood cellulose synthesis was transferred into C. acuminata using the method of Agrobacte- rium-mediated genetic transformation, and an efficient transformation system was developed for C. acuminata on the basis of evaluations of several factors affecting Agrobacterium-mediated DNA transfer rate. The highest transformation rate was achieved when pre-cultttred leaf explants were infected with an Agrobacterium culture corresponding to OD600 （0.5） for 10 min, and cultured on explant regeneration medium for three days. The results of Southern hybridization showed that genomic DNA of the kanamycin-resistant shoots to an UGPase gene probe substantiated the integration of the transgene. Transformation efficiency （6%） was achieved under the optimized transformation procedure, This system should facilitate the introduction of important useful genes into C, acuminata.展开更多
文摘On the basis of sequences of UGPase from plants, a cDNA encoding the enzyme was isolated from the hairy root of Astragalus membranaceus (Fisch.) Bunge. The cDNA consisted of 1 831 bp and encoded a polypeptide of 471 amino acid residues with a calculated molecular weight of 51.5 kD and a deduced isoelectric point of 6.01. Then the open read frame of the cDNA was ligated into pET28(a) + vector and expressed in E. coli BL21. SDS_PAGE showed that the expressed protein was ca. 40% in the total bacterial protein. Enzyme activity assay demonstrated that the UGPase activity in the transformed bacteria was 0.50-3.27 times higher than that of the control. Northern blotting revealed that ugp was expressed in the leaf, stem, root and hairy root of A. membranaceus , with a higher level in root and hairy root.
文摘UDP-glucose pyrophosphorylase is an important enzyme concerned with carbohydrate metabolism in plants. Cloning of UGPase is a premise for further study on molecular level, and it is also crucial for study of carbohydrate metabolism. UGPase cDNA sequence as a template, designed primer, then 3＇-untranslate region （3＇ UTR） of UGPase were amplified by 3＇-rapid amplification of cDNA ends （3＇-RACE）. The results suggested the 3＇ UTR were 243 bp, contained AATAA sequence and Poly（A）.
文摘UGPase （UDP-glucose pyrophosphorylase）, one of the primary enzymes concerned with carbohydrate metabolism, catalyzes the formation of UDPG. By inserting the UGPase cDNA fragment cloned from Saccharum officinarum into PQE-30, the prokaryotic expression vector of PQE-UGP was successfully constructed. Then the vector plasmid of PQE-UGP was transformed into host bacteria M 15 and the expression of target gene was induced by Isopropyl β-D-1-Thiogalactopyranoside （IPTG）. The research laid foundation for study on the prokaryotic expression of UGPase.
基金This research was supported by the National Natural Science Foundation of China(30270842)the Key Project of 10th Five-Year Plan of Hubei Province,China.
文摘The experiment was designed, via storing potato tubers of cv. E-Potato1 and E-Potato3 indifferent temperatures, to explore the variation patterns of reducing sugar (RS) andtotal sugar (TS) contents and enzyme activities that are involved in the pathway ofstarch-sugar metabolism aiming at identifying the main factors that influence the chipcolor. The results showed that low temperature in storage was a main factor thataccelerated the accumulation of RS of the stored tubers and a very significant linearrelationship existed between RS content and chip color index (CCI) of the tubers. Furtheranalysis elucidated that when tubers stored at 4℃, the activities of ADP glucosepyrophosphorylase (AGPase), UDP glucose pyrophosphorylase (UGPase) and sucrose synthase(SuSy) were negatively exponential to the RS content significantly while that of acidinvertase and alkaline invertase was significantly linear to RS content. It suggestedthat these enzymes could play main roles in the cold sweetening of potato tubers throughregulating starch-sugar metabolism.
文摘UGPase gene related with wood cellulose synthesis was transferred into C. acuminata using the method of Agrobacte- rium-mediated genetic transformation, and an efficient transformation system was developed for C. acuminata on the basis of evaluations of several factors affecting Agrobacterium-mediated DNA transfer rate. The highest transformation rate was achieved when pre-cultttred leaf explants were infected with an Agrobacterium culture corresponding to OD600 （0.5） for 10 min, and cultured on explant regeneration medium for three days. The results of Southern hybridization showed that genomic DNA of the kanamycin-resistant shoots to an UGPase gene probe substantiated the integration of the transgene. Transformation efficiency （6%） was achieved under the optimized transformation procedure, This system should facilitate the introduction of important useful genes into C, acuminata.
