title: Lineage-specific evolution of Methylthioalkylmalate synthases (MAMs) involved in glucosinolates biosynthesis.
abstract: Methylthioalkylmalate synthases (MAMs) encoded by MAM genes are central to the diversification of the glucosinolates, which are important secondary metabolites in Brassicaceae species. However, the evolutionary pathway of MAM genes is poorly understood. We analyzed the phylogenetic and synteny relationships of MAM genes from 13 sequenced Brassicaceae species. Based on these analyses, we propose that the syntenic loci of MAM genes, which underwent frequent tandem duplications, divided into two independent lineage-specific evolution routes and were driven by positive selection after the divergence from Aethionema arabicum. In the lineage I species Capsella rubella, Camelina sativa, Arabidopsis lyrata, and A. thaliana, the MAM loci evolved three tandem genes encoding enzymes responsible for the biosynthesis of aliphatic glucosinolates with different carbon chain-lengths. In lineage II species, the MAM loci encode enzymes responsible for the biosynthesis of short-chain aliphatic glucosinolates. Our proposed model of the evolutionary pathway of MAM genes will be useful for understanding the specific function of these genes in Brassicaceae species.
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China ; Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, China Agricultural University Beijing, China.
authors.forename: Jifang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Cheng
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China.
authors.forename: Jianli
authors.initials: J
authors.lastname: Liang
authors.affiliation: Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, China Agricultural University Beijing, China.
authors.forename: Wencai
authors.initials: W
authors.lastname: Yang
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Beijing, China.
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Wang
keywords: Brassicaceae; MAM genes; evolution; glucosinolates; syntenic