The complete mitochondrial genome of Gossypium hirsutum and evolutionary analysis of higher plant mitochondrial genomes.

Guozheng Liu,Dandan Cao,Songnian Hu,Shuangshuang Li,Jinping Hua,Corrinne E Grover,Aiguo Su,Jianing Geng

doi:10.1371/journal.pone.0069476

Abstract

BackgroundMitochondria are the main manufacturers of cellular ATP in eukaryotes. The plant mitochondrial genome contains large number of foreign DNA and repeated sequences undergone frequently intramolecular recombination. Upland Cotton (Gossypium hirsutum L.) is one of the main natural fiber crops and also an important oil-producing plant in the world. Sequencing of the cotton mitochondrial (mt) genome could be helpful for the evolution research of plant mt genomes.Methodology/Principal FindingsWe utilized 454 technology for sequencing and combined with Fosmid library of the Gossypium hirsutum mt genome screening and positive clones sequencing and conducted a series of evolutionary analysis on Cycas taitungensis and 24 angiosperms mt genomes. After data assembling and contigs joining, the complete mitochondrial genome sequence of G. hirsutum was obtained. The completed G.hirsutum mt genome is 621,884 bp in length, and contained 68 genes, including 35 protein genes, four rRNA genes and 29 tRNA genes. Five gene clusters are found conserved in all plant mt genomes; one and four clusters are specifically conserved in monocots and dicots, respectively. Homologous sequences are distributed along the plant mt genomes and species closely related share the most homologous sequences. For species that have both mt and chloroplast genome sequences available, we checked the location of cp-like migration and found several fragments closely linked with mitochondrial genes.ConclusionThe G. hirsutum mt genome possesses most of the common characters of higher plant mt genomes. The existence of syntenic gene clusters, as well as the conservation of some intergenic sequences and genic content among the plant mt genomes suggest that evolution of mt genomes is consistent with plant taxonomy but independent among different species.

Highlights

Mitochondria, where the oxidative phosphorylation and the various biochemical processes take place throughout metabolism, are the main manufacturers of cellular ATP in eukaryotes
The G. hirsutum mt genome possesses most of the common characters of higher plant mt genomes
The existence of syntenic gene clusters, as well as the conservation of some intergenic sequences and genic content among the plant mt genomes suggest that evolution of mt genomes is consistent with plant taxonomy but independent among different species

Summary

Introduction

Mitochondria, where the oxidative phosphorylation and the various biochemical processes take place throughout metabolism, are the main manufacturers of cellular ATP in eukaryotes. The plant mitochondrial genome contains large number of foreign DNA and repeated sequences undergone frequently intramolecular recombination, making it extraordinarily difficult to sequence plant mitochondrial (mt) genomes, those of angiosperms [1,2]. With the sequencing efforts over the past decade, the number of complete mt genomes has been greatly increased [3,4,5]. These finished mt genomes allow a deep analysis on the evolution of the higher plant mt genomes in aspects of gene orders, genome structure, and migration sequences as well as phylogenetic analysis. The plant mitochondrial genome contains large number of foreign DNA and repeated sequences undergone frequently intramolecular recombination. Sequencing of the cotton mitochondrial (mt) genome could be helpful for the evolution research of plant mt genomes

Methods

Results

Conclusion