甘薯番茄红素β-环化酶基因的克隆与转化烟草的研究

Cloning of lyc-b Gene from Sweetpotato(Ipomoea batatas L.) and Transferring the Gene into Tobacco

番茄红素β-环化酶(LYC-B)催化番茄红素形成β-胡萝卜素,是β-胡萝卜素生物合成的关键酶之一。从甘薯块根总RNA逆转录的cDNA中扩增出lyc-b的保守序列后,用cDNA末端快速扩增方法(RACE)获得了该基因全长cDNA,共1844bp,开放阅读框1503bp,编码501个氨基酸。构建了lyc-b植物表达载体p23-lyc-b,通过农杆菌介导法转化烟草,经PCR及Southern杂交表明该基因已整合到烟草的基因组中。

Lycopene β-cyclase,which catalyzes linear lycopene to cycle and become β-carotene,is one of key enzymes in the β-carotene biosynthesis pathway.Total RNA was purified from sweetpotato tuberous roots and was reverse-transcripted into cDNA,and the consensus sequence of the gene for lycopene β-cyclase（lyc-b） was amplified from the cDNA,then total cDNA sequence of lyc-b was obtained by the ways of Rapid Amplification of cDNA End（RACE）.Sequence analysis showed that the complete sequence of lyc-b consists of 1 844 bp,which has an Open Reading Frame of 1 503 bp and encodes a protein of 501 amino acids.The gene was constructed into plant express vector p23-lyc-b,and was transferred into tobacco by Agrobacterium-mediated method.The results of PCR and Southern blot showed that the gene was integrated into tobacco genome.