八氢番茄红素脱氢酶基因超表达载体的构建及表达鉴定

八氢番茄红素脱氢酶(PDS)是植物类胡萝卜素生物合成途径中促进番茄红素合成的关键酶,根据番茄中该酶的编码基因序列设计一对特异引物,通过RT-PCR在番茄中扩增出一个约1 900 bp的全长cDNA片段。对这个全长片段构建了超表达载体,酶切检测表明该片段已插入植物表达载体。采用农杆菌介导的方法转化番茄获得10株转基因植株,PCR检测表明外源基因已导入番茄基因组中。转基因番茄果实的番茄红素含量分析结果表明,转基因后代株系番茄红素平均含量比对照增加了1.4倍,PDS编码基因的超表达有效促进了番茄果实中番茄红素的合成和积累。

Construction of Overexpression Vector for Phytoene Dehydrogenase Gene and Its Expression Identification in Tomato

Phytoene dehydrogenase(PDS) is a key enzyme in the carotenoid biosynthetic pathway.A 1 900 bp full-length cDNA fragment was amplified by RT-PCR from tomato using a pair of specific primers based on the coding sequence of PDS.Using the amplified fragment,the overexpression vector was constructed and identified by digestion with appropriate enzymes.The vector was transformed into tomato by Agrobacterium-mediated method and ten transgenic plants were obtained.The result of PCR revealed that the target gene was integrated into the tomato genome.The lycopene contents in the fruits of transgenic lines were 1.4 times higher than that of the control,suggesting that overexpression of PDS significantly enhanced the lycopene biosynthesis and accumulation in transgenic tomato fruits.