GDP-D-mannose pyrophosphorylase （GMPase） catalyses the synthesis of GDP-D-mannose and represents the first committed step in the synthesis of ascorbate. In the present study, the GMPase gene of tomato was introduced...GDP-D-mannose pyrophosphorylase （GMPase） catalyses the synthesis of GDP-D-mannose and represents the first committed step in the synthesis of ascorbate. In the present study, the GMPase gene of tomato was introduced into potato by Agrobacterium-mediated transformation. Two transgenic lines with higher GMPase expression were selected using qPCR and protein blot analyses. The results showed that the content of L-ascorbic acid （AsA） and the ratio of AsA/ DHA （dehydroascorbate） significantly increased in both leaves and tubers of transgenic potato plants. Both pigment content and photosynthetic rate were much higher in transgenic plants than in wild-type plants. Transgenic plants showed a distinguishable change in phenotype from the wild-type plants. Furthermore, transgenic plants showed delayed senescence.展开更多
A method based on degenerate Oligo primed polymerase chain reaction (PCR) and random amplification of cDNA end (RACE) PCR for cloning a full length cDNA is described. An Amorpha fruticosa cDNA clone encoding UDP gluco...A method based on degenerate Oligo primed polymerase chain reaction (PCR) and random amplification of cDNA end (RACE) PCR for cloning a full length cDNA is described. An Amorpha fruticosa cDNA clone encoding UDP glucose pyrophosphorylase (UGP), a key enzyme producing UDP glucose in the synthesis of sucrose and cellulose, is cloned by using this method. We design 5’ RACE primers based on UGPA1 fragment, which obtains from degenerate PCR. Inverse PCR and nested PCR enable cloning of the remainder 5’ and 3’ end fragments of the gene. The deduced amino acid sequence exhibits significant homology with the other UGP genes cloned. This method is more simple and inexpensive than screening cDNA library, and can be easily adapted to clone other genes.展开更多
抗坏血酸(Vc)是重要的抗氧化剂,在茶树体内的各种生理代谢及抵御非生物胁迫中起重要作用,Vc含量关系到绿茶品质优劣。GDP-D-甘露糖焦磷酸化酶(GMP)是茶树Vc生物合成途径中的关键酶之一。本研究通过RACE-PCR方法从茶树中克隆了GMP c DNA...抗坏血酸(Vc)是重要的抗氧化剂,在茶树体内的各种生理代谢及抵御非生物胁迫中起重要作用,Vc含量关系到绿茶品质优劣。GDP-D-甘露糖焦磷酸化酶(GMP)是茶树Vc生物合成途径中的关键酶之一。本研究通过RACE-PCR方法从茶树中克隆了GMP c DNA全长序列,共计1510 bp,其中包含1 086 bp的开放阅读框(ORF),编码361个氨基酸,推测蛋白分子量为39.599 k Da。BLAST分析表明,茶树GMP基因氨基酸序列与猕猴桃的亲缘性最高,达到96%。实时定量PCR分析表明,茶树新梢芽下第三叶中GMP基因表达量最高,嫩茎中最低,不同品种茶树新梢叶片中表达量存在明显差异。高温胁迫初期,GMP基因表达量及抗坏血酸含量迅速升高,然后逐渐下降且均低于同期对照。展开更多
基金supported by the National Basic Re-search Program of China (2009CB119000)the National Natural Science Foundation of China (30771473)funded by Key Laboratory of Horticultural Crops Ge-netic Improvement, Ministry of Agriculture of China
文摘GDP-D-mannose pyrophosphorylase （GMPase） catalyses the synthesis of GDP-D-mannose and represents the first committed step in the synthesis of ascorbate. In the present study, the GMPase gene of tomato was introduced into potato by Agrobacterium-mediated transformation. Two transgenic lines with higher GMPase expression were selected using qPCR and protein blot analyses. The results showed that the content of L-ascorbic acid （AsA） and the ratio of AsA/ DHA （dehydroascorbate） significantly increased in both leaves and tubers of transgenic potato plants. Both pigment content and photosynthetic rate were much higher in transgenic plants than in wild-type plants. Transgenic plants showed a distinguishable change in phenotype from the wild-type plants. Furthermore, transgenic plants showed delayed senescence.
文摘A method based on degenerate Oligo primed polymerase chain reaction (PCR) and random amplification of cDNA end (RACE) PCR for cloning a full length cDNA is described. An Amorpha fruticosa cDNA clone encoding UDP glucose pyrophosphorylase (UGP), a key enzyme producing UDP glucose in the synthesis of sucrose and cellulose, is cloned by using this method. We design 5’ RACE primers based on UGPA1 fragment, which obtains from degenerate PCR. Inverse PCR and nested PCR enable cloning of the remainder 5’ and 3’ end fragments of the gene. The deduced amino acid sequence exhibits significant homology with the other UGP genes cloned. This method is more simple and inexpensive than screening cDNA library, and can be easily adapted to clone other genes.
文摘抗坏血酸(Vc)是重要的抗氧化剂,在茶树体内的各种生理代谢及抵御非生物胁迫中起重要作用,Vc含量关系到绿茶品质优劣。GDP-D-甘露糖焦磷酸化酶(GMP)是茶树Vc生物合成途径中的关键酶之一。本研究通过RACE-PCR方法从茶树中克隆了GMP c DNA全长序列,共计1510 bp,其中包含1 086 bp的开放阅读框(ORF),编码361个氨基酸,推测蛋白分子量为39.599 k Da。BLAST分析表明,茶树GMP基因氨基酸序列与猕猴桃的亲缘性最高,达到96%。实时定量PCR分析表明,茶树新梢芽下第三叶中GMP基因表达量最高,嫩茎中最低,不同品种茶树新梢叶片中表达量存在明显差异。高温胁迫初期,GMP基因表达量及抗坏血酸含量迅速升高,然后逐渐下降且均低于同期对照。
