脐橙离区β-甘露聚糖酶基因片段克隆和序列分析

Cloning and Sequence Analysis of Endo-β-mannanase Gene Fragment from Abscission Zone of Navel Orange

β-甘露聚糖酶是一种参与细胞壁半纤维素组分甘露聚糖降解的关键酶。为探究该酶与器官脱落的关系,以纽荷尔脐橙(Citrus sinensis Osbeck)果柄离区为材料,采用同源PCR克隆策略,扩增脐橙β-甘露聚糖酶基因片段。结果表明:该序列长度274bp,编码了一段由91个氨基酸残基组成的β-甘露聚糖酶保守区片段。同源比对表明,该序列与GenBank上其他已有的植物β-甘露聚糖酶氨基酸序列的同源性在53%～65%,推断克隆得到的片段是脐橙β-甘露聚糖酶的cDNA片段。

Endo β-mannanase is an important enzyme involved in the mobilization of mannan,which is the component of hemicellulose.In order to investigate the relationship between endoβ-mannanase and organ abscission,the PCR based homologous cloning strategy was used to identify endoβ-mannanase (CiMan) genes from the fruit stalks abscission zone of navel orange (Citrus sinensis Osbeck).The results showed that a 274 bp cDNA encoding 91 amino acids was successfully cloned and characterized.Multiple alignment analysis of amino acid sequences of the putative CiMan cDNA fragment was 53%-65% homologous with other sequences from Genbank.It was supposed that the cDNA fragment was the endoβ-mannanase of navel orange.