摘要： S-腺苷甲硫氨酸脱羧酶（S-adenosyl-L-methionine decarboxylase，SAMDC）是一种通过参与多胺的代谢途径来调节植物生理生化过程的限速酶。通过分析刚毛柽柳（Tamarix hispida）的转录组数据，获得并克隆了SAMDC基因的cDNA序列，将其命名为ThSAMDC。该cDNA序列全长2085bp，包含tiny ORF（tORF）、upstream ORF（uORF）和main ORF（mORF）3个植物SAMDC基因特征ORF。主开放读码框（mORF）长1107bp，编码369个氨基酸多肽，相对分子质量为40.34kD，理论等电点（PI）为4.72。ThSAMDC编码蛋白具有多个较强的亲水性区域，无明显跨膜区。通过与其他多个物种的氨基酸多序列比对结果表明，ThSAMDC具有两个典型的高度保守的结构域：酶原剪切位点（LSESSLF）与蛋白快速降解有关的PEST（TIHVTPEDGFSYAS）结构域。系统发育树结果表明ThSAMDC与菠菜（SoSAMDC）氨基酸序列一致性最高，为77%。实时荧光定量RT-PCR分析显示，ThSAMDC在NaCl、PEG、ABA、CdCl2诱导表达均上调，预示着ThSAMDC可能在刚毛柽柳非生物胁迫应答过程中发挥重要作用。 Abstract: S-adenosyl-L-methionine decarboxylase(SAMDC) is a rate-limiting enzyme that regulates the physiological and biochemical processes of plants by participating in the metabolic pathway of polyamines. The cDNA of S-Adenosine Methionine Decarboxylase gene(named ThSAMDC) was isolated and cloned by analyzing the transcriptome data of Tamarix hispida. The full-length of ThSAMDC is 2 085 bp, with three open reading frames, tiny ORF(tORF), upstream ORF(uORF) and main ORF(mORF). The mORF was 1 107 bp encoding 369 amino acids. The relative molecular weight and isoelectric points(PI) of the putative protein were 40.34 kD and 4.72. ThSAMDC-encoded protein has a number of strong hydrophilic regions, no obvious transmembrane region. Compared to the amino acid multiple sequence alignment of several other species, ThSAMDC includes two highly conserved domains: the proenzyme cleavage site(LSESSLF) and the PEST domain(TIHVTPEDGFSYAS) associated with the rapid degradation of the protein. Phylogenetic tree analysis shows that ThSAMDC has higher sequence similarity of 77% identities to the Spinach(SoSAMDC). Quantitative real-time PCR assay revealed that the mRNA level of ThSAMDC was significantly up-regulated under NaCl, PEG, ABA and CdCl2 treatments in T.hispida, suggesting that ThSAMDC may play an important role in drought resistance, salt tolerance and other stresses. Key words: Tamarix hispida, S-adenosylmethionine decarboxylase, stress responses, gene expression 张玉, 张悦, 张春蕊, 王艳敏, 王玉成, 王超. 刚毛柽柳腺苷甲硫氨酸脱羧酶（ThSAMDC）基因的克隆与胁迫下的表达分析[J]. 植物研究, 2018, 38(1): 132-140. ZHANG Yu, ZHANG Yue, ZHANG Chun-Rui, WANG Yan-Min, WANG Yu-Cheng, WANG Chao. Cloning and Expression Analysis of S-Adenosine Methionine Decarboxylase(ThSAMDC) Gene from Tamarix ramosissima[J]. Bulletin of Botanical Research, 2018, 38(1): 132-140. 1. Groppa M D,Benavides M P. Polamines and abiotic stress:Recent advances[J]. Amino Acids,2008,34(1):35-45.2. Kusano T,Berberich T,Tateda C,et al. Polyamines:essential factors for growth and survival[J]. Planta,2008,228(3):367-381.3. Fos M,Proa o K,Alabad D,et al. 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