中文摘要：

从盐生植物海马齿中克隆了Na＋/H＋逆转运蛋白基因SpNHX1,生物信息学分析结果表明,SpNHX1蛋白与拟南芥AtNHX1和AtNHX2的相似度分别达到了76.35％和77.12％,从而推测,SpNHX1可能具有与AtNHX1和AtNHX2相似的功能,能将Na＋区隔到液泡中,提高植物耐盐性.采用荧光定量PCR的方法,对SpNHX1基因在4种胁迫（600 mmol·L^-1 NaCl胁迫、100 μmol·L^-1 ABA胁迫、4 ℃低温胁迫、20％ PEG6000干旱胁迫）下的表达量进行了研究.结果表明：SpNHX1基因在根和茎中受盐胁迫诱导上调表达,叶中表达量变化较小;而在ABA胁迫、4℃低温胁迫、20％ PEG6000干旱胁迫下,SpNHX1基因的表达受胁迫影响较小,且没有规律性.说明SpNHX1基因的表达与其耐盐性相关,且表达具有组织特性.

英文摘要：

A Na^＋/H ^＋ antiporter gene SpNHX1 from Sesuvium portulacastrumand L. was cloned by using PCR methods. Bioinformation analysis showed that SpNHX1 shared higher identity with AtNHX1 （76.35%） and At- NHX2 （77.12%）, which indicated that the protein SpNHX1 might have similar function as AtNHX1 and At- NHX2 that compartmentalize excessive Na^＋ into vacuole, thus improving plant salt tolerance. Real-time PCR was used for identification of the expression levels of the gene SpNHX1 under 4 different stress treatments, 600 mmol · L^-1 NaCl, 100 μmol · L^-1 ABA, low temperature at 4℃, and 20% PEG6000 drought stress. The gene SpNttX1 was up-regulated in the roots and stems other than in leaves under salt stress. Hardly clear expression tendency of SpNHX1 was observed under 100 μmol · L^-1 ABA, low temperature at 4℃, and drought stress. These illustrated that the expression of the gene SpNHX1 was related to plant salt tolerance, and its expression was tissue-specific.