title: Comparative mitochondrial genome analysis reveals the evolutionary rearrangement mechanism in Brassica.
abstract: The genus Brassica has many species that are important for oil, vegetable and other food products. Three mitochondrial genome types (mitotype) originated from its common ancestor. In this paper, a B. nigra mitochondrial main circle genome with 232,407 bp was generated through de novo assembly. Synteny analysis showed that the mitochondrial genomes of B. rapa and B. oleracea had a better syntenic relationship than B. nigra. Principal components analysis and development of a phylogenetic tree indicated maternal ancestors of three allotetraploid species in Us triangle of Brassica. Diversified mitotypes were found in allotetraploid B. napus, in which napus-type B. napus was derived from B. oleracea, while polima-type B. napus was inherited from B. rapa. In addition, the mitochondrial genome of napus-type B. napus was closer to botrytis-type than capitata-type B. oleracea. The sub-stoichiometric shifting of several mitochondrial genes suggested that mitochondrial genome rearrangement underwent evolutionary selection during domestication and/or plant breeding. Our findings clarify the role of diploid species in the maternal origin of allotetraploid species in Brassica and suggest the possibility of breeding selection of the mitochondrial genome.
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, China.|Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, China.
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, China.
authors.forename: G
authors.initials: G
authors.lastname: Liu
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, China.
authors.forename: N
authors.initials: N
authors.lastname: Zhao
authors.affiliation: School of Plant Biology (M084), The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.affiliation: Biomarker Technologies Corporation, Beijing, China.
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, China.
authors.forename: W
authors.initials: W
authors.lastname: Ma
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, China.|Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, China.|Key Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, China.
authors.forename: M
authors.initials: M
authors.lastname: Zhang
mesh_terms: D005075:Biological Evolution; D001937:Brassica / Q000235:genetics*; D029688:Brassica napus / Q000235:genetics; D001947:Breeding; D004171:Diploidy; D015321:Gene Rearrangement; D054629:Genome, Mitochondrial / Q000235:genetics*; D018745:Genome, Plant / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics; D009149:Mustard Plant / Q000235:genetics; D010802:Phylogeny; D026801:Synteny
keywords: Brassica; heterosplasmic; mitochondrial genome evolution; sub-stoichiometric shifting