盐角草P5CS基因克隆及其在高盐胁迫下的表达分析

Δ1-吡咯啉-5-羧酸合成酶(P5CS)是植物脯氨酸合成途径中的限速酶,但P5CS基因在调节植物耐盐过程中具体的生物学功能尚不明确。本研究利用RT-PCR方法从盐角草中分离得到一个P5CS基因,并对其进行了生物信息学分析和盐胁迫表达特性分析。结果表明,盐角草P5CS基因的c DNA序列全长为2151 bp,编码716个氨基酸,其编码的蛋白质分子量为77.6 k D,等电点为5.83,为稳定蛋白,无信号肽和跨膜区域。二级结构预测显示该蛋白分子中α螺旋结构最多,占43.3%。与已知甜菜、菠菜、滨柃、葡萄中的P5CS基因的氨基酸序列相似性分别为91%、89%、81%和80%,说明该基因与P5CS为同源基因,被命名为Se P5CS。Real-time PCR分析表明,该基因受植物盐胁迫后诱导表达,推测Se P5CS基因在盐角草抵御盐胁迫逆境中起着重要作用。研究结果为明确P5CS基因在植物耐盐应答机制中的生物学功能提供基础。

Cloning and Expression Analysis ofΔ^1-Pyrroline-5-Carboxylate Synthetase(P5CS)Gene in Salicornia europaea

The synthesis of has been r eported to be restricted by TheΔ^1-pyrroline-5-carboxylate synthetase(P5 CS)plays an important role in the proline biosynthetic pathway.To explore the function of P5 CS in Salicornia europaea under salt stress,the full length of P5 CS was obtained by RT-PCR,and analyzed the sequences using bioinformatics approaches and the expression pattern of salt stress by Real-time PCR.The results indicated that was P5 CS in Salicornia europaea was 2151 bp in length,encoding a protein of 716 amino acids.The molecular weight of P5 CS was 77.6 kD,isoelectric point was 5.83 and stability coefficient was 34.12,speculating it was stable protein,and there was no transmembrane domain and signal peptide region.The secondary structure of protein contained 43.3%alpha helixs.The similarity in protein Blast was 91%,89%,81%and 80%with P5 CS genes of Beta vulgaris,Spinacia oleracea,Eurya emarginata,and Vitis vinifera,respectively,the result showed it was a homologous gene of P5 CS in Salicornia europaea,and named SeP5 CS.Real-time PCR analysis indicated that the expression of SeP5 CS induced by the salt stress.It is speculated that SeP5 CS gene plays an important role in regulating in Salicornia europaea response to salt stress,so the cloning of SeP5 CS gene might lay a foundation for the salt resistance and salt tolerance response mechanism of Salicornia europaea and further function analysis.