Cloning and Phylogenetic Analysis of atp6 Gene from Onion

Wang Zhenbao; Huo Yumeng; Miao Jun; Gao Limin; Liu Bingjiang; Yang Yanyan; Wu Xiong; Cheng Fei

Abstract：Cytoplasm male-sterility ( CMS ) is very important in crop genetic breeding .Usually , this phenomenon is associated with structural variation of mitochondrial gene or formation of novel chimeric gene . In order to explore the relationship between atp6 gene and onion CMS , the coding sequence of atp6 gene was cloned from 13 onion sterile lines and 11 maintainer lines .Sequencing results showed that there was one poly-morphic locus ( C/A) in different onion lines .This polymorphic locus randomly appeared in sterile and main-tainer lines , which was not the characteristic difference between two lines .Protein analysis indicated that the variation of the polymorphic locus didn ’ t change the transmembrane structure of atp 6 protein.Further phylo-genetic analysis revealed that atp 6 protein was conserved among different species .Especially the Arg in the fourth transmembrane domain , which was necessary during the H +transport process , was highly conserved . The phylogenetic tree based on atp 6 protein sequence showed that bacteria and viruses were at the base of the tree, followed by fungi , algae and protest , then higher algae , mosses and ferns , higher green flowering plants, especially monocots, were at the top of the tree.