基于EST库的猕猴桃脂氧合酶基因家族成员的克隆

利用猕猴桃EST库及相关生物信息学手段, 从果肉组织克隆了LOX基因家族成员6个, 命名为AdLox1-6。AdLox1、AdLox2、AdLox3和AdLox4 为全长cDNA, 编码区长度分别为2 739、2 595、2 739 和 2 709 bp, AdLox5和AdLox6为cDNA片段, 长度为1 359和1 557 bp。猕猴桃AdLox2和AdLox5氨基酸序列同源性最高, 约74%, 而AdLox3 和AdLox5 仅为49%。生物信息学分析表明, AdLox1、AdLox3、AdLox4 和 AdLox6可能具有132LOX活性, 在N端含有额外约60个氨基酸残基, 而AdLox2和AdLox5则属于92LOX类型。猕猴AdLox1与番茄TomLoxD具有最高氨基酸序列同源性(约80%) , AdLox2和AdLox5与TomLoxA高度聚类, 序列同源性分别为68%和75%, AdLox4和AdLox6与TomLoxC的氨基酸序列同源性分别为62%和63%, AdLox3与番茄LOX基因序列同源性低于55%。

Molecular Cloning of Lipoxygenase Gene Family Members in Kiwifruit Based on EST Database

From Actinidia EST database, six LOX were cloned from kiwifruit flesh tissue, i.e. AdLox1-6. AdLox1, AdLox2, AdLox3 and AdLox4 contained full-length cDNAs with 2 739, 2 595, 2 739 and 2 709 bp, respectively, AdLox5 and AdLox6 were cDNA fragments of 1 359 and 1 557 bp. Among the six kiwifruit LOX genes, AdLox5 and AdLox6 had the highest amino acid sequence identity, which was 74%, while AdLox3 and AdLox5 produced the lowest amino acid sequence identity, which was 49%. Phylogenetic analysis showed that AdLox2, AdLox5 clustered as 92LOX, AdLox1, AdLox3, AdLox4 and AdLox6 clustered as 132LOX. There was a signal peptide sequence of 60 amino acids in allmembers of the 132LOX group, but no similar sequence in the 92LOX genes. AdLox1 was most similar to tomato TomLoxD at 80% identity at the amino acid level, AdLox2 and AdLox5 matched to TomLoxA with 68 and 75% identity, respectively, and AdLox4 and AdLox6 showed 62% and 63% sequence identity to TomLoxC, AdLox3 had less than 55% identity to LOX genes from tomato.