Isolation and Expression Analysis of Na⁺/ H⁺ Antiporter Gene SpNHX1 from Sesuvium portulacastrumand L.

Key words: 
• Sesuvium portulacastrumand L. /
• Na⁺/ H⁺ antiporter /
• SpNHX1 /
• salt tolerance /
• gene expression

Abstract: 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 At NHX1（ 76. 35%） and AtNHX2（ 77. 12%）,which indicated that the protein SpNHX1 might have similar function as At NHX1 and AtNHX2 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,600mmol·L^-1 Na Cl,100 μmol·L^-1ABA,low temperature at 4℃,and 20% PEG6000 drought stress. The gene SpNHX1 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^-1ABA,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.