转獐茅AlNHX基因烟草的耐盐生理研究

目的]研究从禾本科盐生植物獐茅中分离的液泡膜Na+/H+逆向转运蛋白基因AlNHX在盐胁迫下的功能和表达。方法]转化AlNHX的烟草经过抗生素和PCR筛选后,用不同浓度的NaCl处理30 d,测定其单株干重、相对电导率、细胞渗透压以及K+/Na+比。结果]在不同浓度NaCl处理下,转基因烟草的相对干重和细胞渗透压均高于对照烟草。在300 mmol/L NaCl处理下,转基因烟草的相对电导率明显低于对照。K+、Na+含量测定表明在盐胁迫下转基因烟草的根部和叶片均维持一个相对较高的K+/Na+水平。结论]AlNHX是一个有效的耐盐基因,可进一步应用于单子叶农作物的基因改良研究。

Study on Physiology of Salt Tolerance in ALNHX Transgenic Tobacco

Objective] The aim of the research was to investigate the function and expression of AlNHX isolated from a graminaceous halophyte Aeluropus littoralis under salt stress.Method] After screened by kanamycin and PCR,the AlNHX-transgenic tobacco was treated with different NaCl concentration for 30 days,then the dry weight,relative electronic conductivity,osmotic potential as well as K /Na ratio was measured.Result]The results indicated that with different NaCl concentration treatment,both the dry weight and osmotic potential of transgenic plants were higher than wildtype tobacco.Under 300 mmol/L NaCl treatment,the relative electronic conductivity of transgenic plants was significantly lower than wild-type tobacco(P<0.01).The analysis of ion content suggested that under high salt stress the transgenic plants kept a relative high K /Na ratio in the leaves and roots compared with wild-type plants.Conclusion]AlNHX was an effective gene for improving the salt tolerance of monocot crops via genetic engineering.