Genomic characterization of the S-adenosylmethionine decarboxylase genes from soybean
Genomic characterization of the S-adenosylmethionine decarboxylase genes from soybean
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DOI：
10.1007/s00122-003-1507-6
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发表时间：
2004-03
影响因子：
5.4
通讯作者：
Ai-Guo Tian;Jingyan Zhao;Jin‐Song Zhang;J. Gai;S. Chen
中科院分区：
文献类型：
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作者：
Ai-Guo Tian;Jingyan Zhao;Jin‐Song Zhang;J. Gai;S. Chen
从大豆表达序列标签中克隆了一个编码多胺合成关键酶S-腺苷甲硫氨酸脱羧酶（SAMDC）的基因GmSAMDC 1，并对其进行了序列分析。与其他植物SAMDC相比，GmSAMDC 1蛋白具有几个高度保守的区域，包括一个推定的前酶切割位点和一个PEST序列。GmSAMDC 1 mRNA的5′端前导序列含有两个额外的开放阅读框（ORF），可能参与调控GmSAMDC 1 mRNA的翻译过程。GmSAMDC 1基因的5′端前导序列中含有3个内含子，而3′端非翻译区和主要的酶原ORF中没有内含子。在内含子2上发现了一个简单重复序列（SSR），利用该SSR将GmSAMDC 1基因定位在D1连锁群上。Southern-blot和PCR分析表明，大豆属大豆亚属和大豆亚属GmSAMDC 1基因的基因组结构不同。还鉴定了假基因GmSAMDC 2。该基因不含内含子，丢失了两个uORF。Northern-blot分析表明，GmSAMDC 1基因的表达受盐、干旱和低温的诱导，而不受伤害的诱导，表明该基因参与了多重胁迫条件下的应答。
A full-length geneGmSAMDC1, encoding the S-adenosylmethionine decarboxylase (SAMDC), a key enzyme involved in polyamine biosynthesis, was identified from soybean expressed sequence tags and was characterized.GmSAMDC1encoded a peptide of 355 amino acids. When compared with other plant SAMDCs, the GmSAMDC1 protein had several highly conserved regions including a putative pro-enzyme cleavage site and a PEST sequence. The 5′ leader sequence of the theGmSAMDC1mRNA contained two additional open reading frames (ORFs), which may regulate the translational process. The genomic sequence of theGmSAMDC1 gene contained three introns in the 5′ leader sequence, but no intron in the 3′-UTR or the main pro-enzyme ORF. A simple sequence repeat (SSR) was found in intron 2, and theGmSAMDC1gene was mapped to linkage group D1 using this SSR. The genomic organization of theGmSAMDC1gene in the subgenusGlycineand the subgenusSojawas found to be different by Southern-blot and PCR analysis. A pseudogene,GmSAMDC2, was also identified. This gene contained no intron and lost its two uORFs. Northern-blot analysis showed that theGmSAMDC1gene expression was induced by salt, drought and cold, but not induced by wounding; suggesting that the gene was implicated in response to multiple-stress conditions.