盐生植物适应高盐环境涉及复杂的细胞结构、生理过程和代谢调控机制，其中Na+/H+逆向转运蛋白扮演至关重要的角色。Na+/H+逆向转运蛋白分布在细胞质膜和液泡膜上，液泡膜上的Na+/H+逆向转运蛋白（NHX）将细胞中的Na+逆着Na+浓度梯度运送到液泡中区隔化集中，质膜上的Na+/H+逆向转运蛋白（SOS）将细胞质中的Na+逆向运送到胞外高Na+环境中，以减少钠离子对细胞器的毒害并维持细胞的渗透平衡。白刺是内蒙地区的自然植物区系盐生植物，其自然抗逆性突出，是干旱盐碱地带植物群落的建群种。因此，研究白刺的耐盐分子机理、开发其耐盐基因资源具有重要意义。本申请项目拟分离白刺的NHX和SOS基因，通过对这两个基因在盐胁迫下的表达特性及离子亚细胞定位分析，探明白刺的耐盐机理，并通过转基因等方法分析这两个基因在甜土植物中的表达，为今后利用该基因进行牧草、农作物和林木的耐盐性遗传改良提供理论和实验依据。

The mechanism of that saline plants adapt to salt-stress environment, involves in complex factors, such as cell structure, physiological processes and metabolism regulation. Among these complicated processes, Na+/H+ antiporters play an important role in plant salt-tolerance. Na+/H+ antiporters are integral proteins embeded in vacuolar membrane and cytomembrane. The cytomembrane Na+/H+ antiporter proteins can transport cytoplasmic Na+ to the exocellular, and the vacuolar Na+/H+ antiporter proteins can deliver Na+ into the vacuoles against the electrochemical gradient. The compartmentation of Na+ provides an effective mechanism to avert the deleterious effects of Na+ on cytosol, and maintain an osmotic potential by Na+ in vacuoles. . Nitraria L. is a genus of flowering plants in Zygophyllaceae family, which grows primarily in deserts and semideserts, and exhibits strong salt-resistance. Therefore, the research on molecular mechanism of salt-tolerance in Nitraria is very necessary. In the project, our objective is to elucidate salt-tolerance mechanism and exploit salt-tolerance related genes of Nitraria L. We plan to isolate orthologs of NHX and SOS genes that encoded vacuolar and cytomembrane Na+/H+ antiporters, respectively, from Nitraria L., and analyze their salt-tolerance mechanism by investigating expression pattern of the two genes and ion subcellular location under salt-stress conditions. On the other hand, for analyzing application of the two genes in salt-tolerance improvement of plants, we plan to transfer the two genes into Arabidoposis thaliana and Populus tomentosa, and investigate traits of the transgenic plants. The research will provide theoretical and experimental bases for improving salt tolerance of forage grass, agricultural crops and forest trees through genetic transformation with salt-tolerance related genes of the important saline plants.