中文摘要：

利用兼并PCR及RACE技术克隆了西伯利亚白刺的肌动蛋白基因（Nitraria sibirica Actin,NsAct）,并对其基因结构和表达特性进行了分析。所克隆的NsAct cDNA全长序列为1 831bp,包含1 134bp的开放阅读框,编码377个氨基酸;基因组DNA全长序列为2 913bp,包含5个外显子和4个内含子。系统进化分析结果显示,NsAct与其他植物的肌动蛋白基因具有较高的同源性,与芒果（无患子目）亲缘关系最为接近。基因表达特性分析的结果显示,该基因在根、茎、叶中的表达量基本一致;在干旱、盐、低温及外源脱落酸胁迫下,表达量无明显变化,这些结果验证了该基因作为分子内标的可靠性。

英文摘要：

Nitraria sibirica actin gene（NsAct） was cloned using degenerated-PCR and RACE technique,and gene structure and expression pattern were analyzed.Full-length sequence of the NsAct cDNA contains 1 831 bp,which has a 1 134 bp open reading frame（ORF） encoding 377 amino acids.Genomic DNA of the NsAct contains 2 913 bp,including 5 extrons and 4 introns.The NsAct amino acid sequence shows a high homology to that of the other plants,and phylogenetic tree generated from the nucleotide sequences of plant actins revealed that the NsAct shows close genetic relation with Mangifera indica（sapindales）.The NsAct equally expressed in root,stem,and leaf,and no obvious change in expression level was observed under stress conditions of drought,salt,cold,and exogenous abscisic acid（ABA）.