星星草PtGAPDH基因的克隆与表达分析

Cloning and expression of PtGAPDH from Puccinellia tenuiflora

本试验利用RACE(rapid amplification of cDNA ends)克隆技术从星星草中克隆得到抗盐碱相关基因甘油醛-3-磷酸脱氢酶(GAPDH)的cDNA全长序列,其GeneBank登录号为JX411954。PtGAPDH基因开放阅读框为1014bp,编码337个氨基酸。该氨基酸序列与高羊茅、大麦、小麦、水稻等禾本科作物具有较高的序列相似性。系统进化分析表明,PtGAPDH基因编码蛋白与单子叶植物的GAPDH具有较近的亲缘关系。Northern杂交分析显示,在一定盐碱胁迫条件下,随着处理试剂Na2CO3溶液浓度的增加,PtGAPDH基因在盐碱胁迫下的叶片和根部表达量都显著升高;超过最大耐受量后,PtGAPDH基因表达丰度逐渐降低。PtGAPDH基因的表达模式代表了星星草在盐碱胁迫下其自身的生理生化变化对分子水平上的基因表达丰度产生的影响趋势。

A full length cDNA named PtGAPDH related to saline-alkali tolerance was cloned from Puccinellia tenuiflora by RT-PCR and RACE （rapid amplification of cDNA ends）. PtGAPDH gene with 1014 bp open reading frame encoded a protein with a predicted length of 337 amino acids. Phylogenetic analysis indicates that this gene, denoted PtGAPDH, has sequence characteristics similar to other monocotyledon GAPDH genes. Northern blot shows the expression of PtGAPDH has increased with the growth of the concentration of Na2CO3 in the proper realm, otherwise, has decreased both in leaves and roots. The expression pattern of Pt- GAPDH gene stands for the regular effects of the saline-alkali stress on the gene expression of P. tenuiflora on the molecular standard.