【摘要】 在先期研究的基础上,结合运用电子克隆和反转录PCR技术克隆玉米PP2C基因的全长cDNA序列,再分别应用实时荧光定量PCR和非放射性标记法,测定干旱胁迫条件下耐旱性不同的自交系PP2C基因的mRNA表达差异和酶活性差异,以探讨PP2C酶活性与玉米耐旱性的关系。结果表明,我们克隆的全长cDNA序列为玉米PP2C基因家族的新成员,开放阅读框长1164bp,编码388个氨基酸残基。将这一基因命名为ZmPP2Ca,GenBank注册号为EF195257。在干旱胁迫条件下,该基因在耐旱自交系中下调表达,使PP2C酶活性降低;在不耐旱自交系中上调表达,使PP2C酶活性升高。ZmPP2Ca基因的差异表达以及由此引起的PP2C酶活性差异,可能与干旱胁迫条件下玉米细胞的信号传导有关。更多还原

【Abstract】 Based on the previous study, we cloned the full length cDNA sequence of serine/threonine protein phosphatase 2C (PP2C) by electronic cloning and reverse transcription PCR, assayed its expression difference and enzyme activity among differ-ent inbred lines under drought stress by fluorescence quantitative real-time PCR and non-radioactive labeled method respectively, and analysed the relationships between the enzyme activity and drought tolerance in maize. The result indicated that the full length cDNA sequence we cloned is a new member of PP2C gene family in maize, and its open reading frame of 1 164 bp en-codes 388 amino acid residues. This gene was denominated as ZmPP2Ca and registered at GenBank (accession number: EF195257). Under drought stress, its down-regulated expression decreased enzyme activity of PP2C in drought-tolerant inbred lines, and its up-regulated expression increased enzyme activity of PP2C in drought-sensitive inbred lines. The differential expres-sion of gene ZmPP2Ca and difference of PP2C activity are speculated to be implicated in signal transduction in maize cells under drought stress.更多还原