莲瓣兰大雪素AP1 MADS-box基因的克隆和系统发育分析

Isolation and Phylogenetic Analysis of AP1 Gene from Cymbidium tortisepalum

随着植物中越来越多的MADS-box基因被克隆出来,人们对经典的ABC模型进行了改进和完善,提出花发育的ABCDE模型,通过RT-PCR和RACE技术从莲瓣兰大雪素花器官中克隆得到AP1同源基因AP1a和AP1b的cDNA全长:AP1a基因全长为1 054bp,其开放阅读框为744bp;AP1b基因全长为944bp,其开放阅读框为516bp。从莲瓣兰大雪素中得到2个AP1同源基因,说明在大雪素中AP1出现基因松弛,所以出现多个拷贝。通过序列比对以及系统发育分析表明,莲瓣兰AP1a基因与春兰具有很高的相似度,达到99.1%,莲瓣兰AP1b基因与萼脊兰具有中等程度的相似度,达75.8%,但从大雪素花器官提取的同源基因AP1a和AP1b的相似度很低,仅为65.4%。这表明AP1基因在不同品种植物间具有保守性,而在同一个物种中又存在着功能的分化。

With more and more plant MADS-box genes have been cloned,the classic ABC model has been improved,and ABCDE model of flower development had formed.Using rapid amplification of cDNA ends（RACE）amplified the full-lenth cDNA of AP1 aand AP1b.the full lenth cDNA of AP1 a was 1 054 bp,contained one ORF（744bp）,the full lenth cDNAof AP1 bwas 944bp,and it contained one ORF for 516 bp.This suggest that AP1 shows gene loose and come out with may copy in Cymbidium tortisepalum.The phylogenetic analysis of AP1 aand AP1b gene of Cymbidium tortisepalum show that AP1 ain Cymbidium tortisepalum was similar with that in Cymbidium faben with the similarity of 99.1%,however AP1 b was similar with sedirea japonica with the similarity of 65.4%.And the similarity between AP1 aand AP1b in Cymbidium tortisepalum was only 65.4%.This suggests that AP1 gene show the conservative in different plant,but it also show functional differentiation in the same species.