‘湖景蜜露’桃果实酰基辅酶A氧化酶编码基因的克隆及表达分析

【目的】根据国际桃基因组序列信息，进行克隆和表达分析与桃果实内酯类合成相关的果肉组织酰基辅酶A氧化酶(Acyl-CoA oxidase，ACX)的5个候选基因，为进一步开展桃香气物质代谢分子机理的研究提供新的研究方向。【方法】根据Phytozome(www.phytozome.org/peach)发布的桃ACX全基因组序列设计特异引物对5个基因全长进行克隆测序，与参考编码序列进行比对和编码蛋白性质进行分析，并对这些成员进行组织特异性表达分析。【结果】获得了桃果肉组织中表达的5个ACX编码基因全长序列，PpACX1、PpACX3的CDS区没有突变，PpACX2核苷酸序列871位处A突变为G，导致氨基酸序列中谷氨酰胺变异为精氨酸；PpACX4的核苷酸序列在80位和368位存在两处同义突变；PpACX5在475位处A突变为C，导致蛋氨酸突变为亮氨酸。同源性分析结果显示，这些基因的氨基酸序列与番茄、南瓜、大麦、葡萄等高等植物的氨基酸序列同源性很高。系统进化树分析表明，5个基因家族成员中，除PpACX4外其余4个成员处在同一个进化分支上，且与南瓜、葡萄、番茄、大豆等的亲缘关系较近。在根、茎、叶、果实表达证明，PpACX1是果实中主要大量表达成员。【结论】‘湖景蜜露’桃果实中表达的5个桃ACX编码基因全长与基因组数据数据库有一定差异，PpACX1为5个成员中较为关键的基因成员。

Molecular Cloning and Sequence Analysis of Acyl-CoA Oxidase Gene from ’Hujingmilu’ Peach Fruit

【Objective】The aim of this study is to clone and analyse the five genes of acyl-CoA oxidase(ACX) from peach(Prunus persica L. Batsch) flesh. 【Method】Specific primers were designed based on the genome of peach of ACX published onPhytozome (www.phytozome.org), and the full-length of the five genes were cloned. 【Result】In this study, the full-length of thefive genes of ACX from peach fruit was obtained. There was no mutation in the CDS of Pp4CX1 and PpACX3. A mutates to G inPpACX2 on seq 871, which leads to Gin mutates to Arg. In PpACX4, there are two same sense mutations in seq 80 and 368. Amutates to c in PpACX5 on seq 475, which leads to Met mutates to Leu. The amino acid sequence of peach ACX was highlyhomologous with other species, especially tomato, squash, barley, and grape. Phylogenetic analysis showed that five gene familymembers were in the same evolutionary branch except PpACX4 which had a more closer relationship with pumpkin, grape, tomato,soybean, etc. PpACX1 was proved to be the highest expression member through the gene expression in root, stalk, leaf and fruit. 【Conclusion】There are some differences between the 5 expressed genes of ACX cloned from ’Hujingmilu’ peach fruit and thedatabase of the genome. PpACX1 was proved to be the most important gene member in peach fruit.