( 2 ) at translation level plant mutual sequence of starting translation aaca was added to start codon of t - pa gene by pcr ampliation and plant expression vector pbet was constructed ( 2 )在翻译水平上通过pcr扩增的方式在t - pa基因起始密码子处添加了植物翻译起始共有序列aaca ，构建了植物表达载体pbet 。
2.
( 3 ) at post - translation level plant mutual sequence of starting translation aaca and eukaryotic secretory signal peptide sequence was added to 5 ' - flanking region of t - pa gene and kdel ( sequence located to endoplastic reticulum ) to 3 ' - flanking region by pcr amplication and plant expression vector pbemt was constructed ( 3 )翻译后水平通过pcr扩增的方式在t - pa基因5端添加了真核分泌信号肽序列和植物翻译起始共有序列aaca ，在3端添加了内质网定位序列kdel ，构建了植物表达载体pbemt 。
