冬枣两个ACC氧化酶基因的cDNA克隆及其表达模式

Cloning and Expression Patterns of Two cDNAs Encoding ACC Oxidase in‘Dongzao’Jujube

根据植物ACC氧化酶(ACO)家族的氨基酸和核苷酸保守区序列设计简并引物,采用3′RACE技术从半红期冬枣果实中分离了两个ACO同源基因片段,随后通过PCR技术进一步获得了两个包含完整开放阅读框(ORF)及3′端非编码区(UTR)序列的ACO基因的cDNA,即ZjACO1和ZjACO2。两个基因序列在GenBank中的登录号为EU216549和EU216550,其大小分别为1115bp和1105bp,编码蛋白大小分别为319个和321个氨基酸。ZjACO1和ZjACO2在核苷酸和氨基酸水平上的同源性分别为79.4%和84.0%。Northern杂交结果表明,这两个基因在冬枣叶片中不表达,在果实不同发育阶段中的表达具有明显差异。

Two ACC oxidase （ACO） cDNA fragments were isolated from half-red Dongzao jujube fruit by 3＇ RACE technique using degenerate primers corresponding to the conserved nucleotide and amino acid region sequences of the ACO family, then the 5＇ end encoding sequences of both cDNAs were obtained by RTPCR experiments. The two cDNAs, named as ZjACO1 and ZjACO2, contain an ORF （open reading frame） with 3＇UTR （untranslated region） respectively. Their accession numbers in GenBank are EU216549 and EU216550. The two cDNAs are 1115 bp and 1105 bp in length, while the predicted proteins of them are 319 and 321 aa long, respectively. The similarity between ZjACO1 and ZjAC02 is 79. 4% at nucleotide level, and 84. 0% at amino acid level. The result of Northern blot analysis indicated that expressions of two cDNAs in ju-jube leaves were both undetectable, while their expressions at the development and ripening stages of jujube fruit were obviously different.