中文摘要：

拟南芥液泡膜Na＋/H＋逆向转运蛋白基因（AtNHX1）在植物耐盐机制中有重要作用。为了鉴定AtNHX1基因功能和创制耐盐烟草新种质,本研究用农杆菌介导法将rd29A启动子驱动的AtNHX1基因导入烟草（Nicotiana tabacum L.）,获得72株卡那霉素抗性再生植株,17株在MS＋85.5mmol/LNaCl培养基上生长良好。对其进行PCR、Southern杂交和Northern杂交检测,证实AtNHX1基因已整合到烟草基因组中,并进行正常转录,且其转录受盐逆境的诱导。在含盐（85.5、171、256和342mmol/LNaCl）培养基上进行对照植株和转基因植株生长及叶片丙二醛含量的分析,结果显示,转基因株系的生长势和根发生能力明显优于对照,且叶片丙二醛含量显著低于对照,表明rd29A启动子驱动AtNHX1基因的导入和表达可显著提高转基因烟草植株的耐盐性。结果提示rd29A启动子驱动的AtNHX1基因表达单元可在异源植物中正常转录和表达,可用于植物耐盐基因工程育种。

英文摘要：

The tonoplast Na^＋/H^＋ antiporter gene（AtNHX1） of Arabidopsis thaliana playes important roles in saline tolerance of the plant.In order to identify of AtNHX1 gene function and create new germplasm of tobacco,the AtNHX1 gene under the control of stress-induced rd29A promoter was transferred into tobacco（Nicotiana tabacum L.） tissues by Agrobacterium-mediated transformation.A total of 72 regenerated plants resisted to Kanamycin were obtained,of which 17 grew well in MS medium supplemented with 85.5 mmol/L NaCl.Subsequent PCR,Southern and Northern hybridizations validated the genomic insertion and normal expression of the AtNHX1 gene in the transgenic tobacco plants.The up-regulated expression of AtNHX1 gene was induced by salt challenge.The growth and root development of the transgenic plants were significantly better than that of the controls in the medium supplemented with 171,256 and 342 mmol/L of NaCl,while the concentration of malonyldialdehyde in the leaves of transgenic plants was significantly lower than that in the controls.The results indicated that the insertion and expression of AtNHX1 gene controlled by rd29A promoter could significantly enhance the salt tolerance of transgenic tobacco plants.These results revealed that the AtNHX1 gene regulated by rd29A promotercould be normally expressed in heterologous plant and its expression could improve the saline tolerance of the receipt plant.Therefore,genetic transformation of the AtNHX1 gene can be one of gene-engineering strategies for breeding saline tolerant crop.