AtNHX5基因过量表达对拟南芥耐盐性的影响

Overexpression of AtNHX5Increases Salt Tolerance of Arabidopsis thaliana

为了研究AtNHX5基因在植物耐盐中的作用,构建了植物过量表达载体pROKⅡ-AtNHX5,并转化拟南芥。结果显示:(1)RT-PCR检测表明,转基因拟南芥中AtNHX5基因的表达大幅提高。(2)对转基因纯合株系进行耐盐性分析显示,AtNHX5过量表达提高了植株在种子萌发和苗期的耐盐性。(3)转基因植株在盐处理下的干重、鲜重以及地上部分Na+、K+含量均高于野生型对照。在200mmol/L NaCl处理下,以转基因株系a1-4为例,其地上部分单株鲜重、单株干重、K+含量分别是野生型的1.27、1.54、1.16倍,较野生型显著升高。研究表明,过量表达AtNHX5基因促进了盐胁迫下转基因植株对K+的吸收,转基因拟南芥的耐盐性明显提高。

To investigate the role of AtNHX5 in plant salt resistance, the plant expression vector pROK II - AtNHX5 was constructed and introduced into Arabidopsis thaliana. RT-PCR assay showed that： （1）At- NHX5 was over-expressed in the transgenic lines. （2）Several transgenic homozygous lines and wild-type plants were evaluated for salt stress tolerance, the results suggest that AtNHX5 transgenic plants were more tolerant to high NaC1 concentrations during germination and seedling stages when compared with wild-type plants. Under saline conditions,both fresh and dry weights of the transgenics as well as Na＋ and K＋ contents were much higher than that of wild-type. To take transgenic plant al-4 as an example, the shoot fresh weight,dry weight and K＋ content were 1.27,1.54 and 1.16 fold, respectively compared with wild types under 200 mmol/L NaC1 treatment,which were significantly higher than that in wild types. These results demonstrate that overexpression of AtNHX5 in Arabidopsis promoted the absorbing capaci- ty of K＋ and enhanced the salt tolerance of plants.