过量表达大叶补血草LgNHX1基因对拟南芥耐盐性的影响

Overexpressing LgNHX1 Gene Improved Salt Tolerance of Arabidopsis thaliana

利用植物表达载体pCAMBIA1301和农杆菌GV3101将LgNHX1(全长1 656 bp)基因在拟南芥中过量表达。在含30 mg/L潮霉素的培养基上筛选获得LgNHX1的纯合转化子,并对其进行了分子鉴定和耐盐性分析。结果显示,经PCR和RT-PCR鉴定,野生型植株(对照)没有出现扩增条带,而转基因株系有相应的扩增条带,表明LgNHX1的确已经整合到拟南芥的基因组中,并已正常转录。在不同盐浓度处理下,转基因株系生长情况好于野生型对照;转基因植株地上部分和根的干重、鲜重相对高于野生型对照,但差异没有达到显著水平;当盐浓度达到150-200 mmol/L时,两个转基因株系的Na+含量显著高于野生型,K+含量极显著高于野生型。以上结果表明,过量表达LgNHX1基因可能增强了拟南芥将Na+区隔化至液泡的能力,提高了转基因拟南芥的耐盐能力。

In this research,LgNHX1 gene（1 656 bp）was inserted into plant vector pCAMBIA1301.The resulting plasmids were mobilized to Agrobacterium tumefaciens strain GV3101 used for plant transformation.The gene was introduced into Arabidopsis thaliana（ecotype Columbia）by Agrobaterium tumefaciens-mediated transformation with floral-dipping method under the control of CaMV 35S promoter.Transformants were selected for their ability to grow on medium containing hygromycin（30 mg/L）.Several homozygous lines transformed with LgNHX1 gene were selected and used for further molecular and physiological determination.PCR analysis indicated that LgNHX1 gene had been integrated into the transgenic plants genomes.RT-PCR analysis revealed the expression of LgNHX1 gene in T3 plants of several non-segregation transgenic lines.Under different concentrations of NaCl treatment,the transgenic plants grew more vigorously than wild-type plants.The fresh weight and the dry weight of the transgenic lines were higher than that of wild-type plants,and transgenic plants showed a tendency to accumulate more Na＋ and K＋ under saline conditions than wild type plants.Summarily,overexpressing of LgNHX1 gene improved salt tolerance of transgenic plants.