普通烟草<i>PPO</i>基因家族的鉴定与表达分析

普通烟草PPO基因家族的鉴定与表达分析

摘要: 为探明烟草多酚氧化酶（Polyphenol oxidase，PPO）基因家族的生物学功能，对普通烟草PPO基因家族进行了鉴定和分析。结果表明，普通烟草有10个NtPPOs基因，基因结构简单，蛋白结构高度保守。7个NtPPOs基因分别定位在第3、4、5和20号染色体上，另外3个NtPPOs基因无具体定位信息。NtPPOs蛋白与番茄、马铃薯的亲缘关系较近。qRT-PCR结果表明，8个NtPPOs基因在幼蕾、花瓣和蒴果中高量表达，在根、茎、叶中表达量较低；NtPPO7与NtPPO8在根中表达量较高，表明NtPPOs在进化过程中出现了功能分化。

Abstract: To explore the biological function of polyphenol oxidase (PPO) gene family in tobacco, PPO gene family from Nicotiana tabacum was identified and analyzed. Ten NtPPOs were identified, which were simple in structure. The motif organizations of ten NtPPOs were high conservation. Seven NtPPOs were mapped on the third, fourth, fifth and twentieth chromosomes, and the remaining genes were not located. The genetic relationship of PPOs among Nicotiana tabacum, tomato and potato was close. qRT-PCR results indicated that eight NtPPOs were highly expressed in bud, petal and capsule, contrary to root, stem and leaves. NtPPO7 and NtPPO8 were preferentially expressed in root, which suggested that the functions of NtPPOs diverged in evolution.