莲多酚氧化酶基因的克隆及序列分析

Molecular Cloning and Analysis of Polyphenol Oxidase Gene in Lotus

多酚氧化酶是一类普遍存在于植物、真菌、昆虫的质体中,由核基因编码能与铜相结合的金属蛋白酶。它是许多果蔬等农产品酶促褐变的主因,也在植物的光合作用、抗病虫害、生长发育以及花色的形成中起一定作用。用RT-PCR方法,从中国莲(Nelumbonucifera)幼叶RNA中成功扩增出ppo的部分序列,经克隆测序,得到长度在978～1057bp的序列共7个,编码326～352个氨基酸。与其他物种PPO进行比较,其核苷酸序列相似性为83%～85%,氨基酸序列相似性为84%～99%。莲ppo的成功克隆为抑制莲藕的酶促褐变,提高莲的抗虫抗病性等的研究打下了良好的基础。

Polyphenol oxidase （PPO） is a ubiquitous copper metalloprotein in the plastids of many plant species, fungi and insects. It is believed to be the primary response to the deleterious browning of many fruits and vegetable crops and is thought to be involved in plant photosynthesis, plant-pest interactions, grown and development, flower coloration. By using RT-PCR method, partial sequences ofppo genes were amplified from cDNA of Nelumbo nucifera＇s young leaves. After cloning and sequencing, 7 sequences ranging from 978bp to 1 05Top were obtained, and they encoded 326 to 352 amino acids. Compared these sequences with other PPO from GenBank, it reveals a similarity higher than 79% at the nucleotide level, and 61% at the amino acid level. The success of cloning ppo gene from lotus builds a great base for its browning effect controlling and plant-pest interactions researches.