二色补血草海藻糖-6-磷酸磷酸酯酶基因的克隆及分析

Cloning of Trehalose-6-phosphate Phosphatase Gene from Limonium bicolor

以二色补血草叶片组织为材料构建了cDNA文库,文库的初始滴度为2.0×106pfu,重组率为95%,平均插入片段为0.8 kb,扩增后文库的滴度为4.0×109pfu.mL-1。通过随机测序从文库中获得的海藻糖-6-磷酸磷酸酯酶(trehalose-6-phosphate phosphatase,TPP)基因的全长cDNA序列,该序列长1 986 bp,其中5’非翻译区163 bp,3’非翻译区680 bp,开放读码框长1 143 bp,编码380个氨基酸,蛋白分子质量为42KD,理论等电点为6.68。海藻糖-6-磷酸磷酸酯酶在海藻糖合成过程中起关键作用,该基因的克隆为研究海藻糖在二色补血草中的合成奠定了基础。

A eDNA library was constructed from leaves of Limonium bicolor. Results show that the primary titer of the eDNA library was 2. 0 ×10^6 pfu/mL, the rate of recombination was 95%, the average size of the inserts was 0. 8 kb in length, and the titer of amplified library was 4. 0 × 10^9 pfu/mL^-1. A trehalose-6-phosphate phosphatase （TPP） gene was obtained by random sequencing of the library clones. The TPP gene, having an open reading frame of 423 bp encoding ：a deduce amino acid sequence of 380 residues, was 1986 bp in length, including 163 bp of 5＇ untranslated region and 680 bp of 3＇ untranslated region. The protein molecular weight was 42 KD and its isoelectric point was 6. 68. TPP gene plays an important role in synthesis of trehalose. The cloning of TPP gene lays a solid basis for investigating the biosynthesis of trehalose in L bicolor.