AUTHOR=Zhang Jifang , Wang Xiaobo , Cheng Feng , Wu Jian , Liang Jianli , Yang Wencai , Wang Xiaowu 

TITLE=Lineage-specific evolution of Methylthioalkylmalate synthases (MAMs) involved in glucosinolates biosynthesis

JOURNAL=Frontiers in Plant Science

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00018

DOI=10.3389/fpls.2015.00018

ISSN=1664-462X

ABSTRACT=<p>Methylthioalkylmalate synthases (MAMs) encoded by <italic>MAM</italic> genes are central to the diversification of the glucosinolates, which are important secondary metabolites in Brassicaceae species. However, the evolutionary pathway of <italic>MAM</italic> genes is poorly understood. We analyzed the phylogenetic and synteny relationships of <italic>MAM</italic> genes from 13 sequenced Brassicaceae species. Based on these analyses, we propose that the syntenic loci of <italic>MAM</italic> genes, which underwent frequent tandem duplications, divided into two independent lineage-specific evolution routes and were driven by positive selection after the divergence from <italic>Aethionema arabicum</italic>. In the lineage I species <italic>Capsella rubella</italic>, <italic>Camelina sativa</italic>, <italic>Arabidopsis lyrata</italic>, and <italic>A. thaliana</italic>, the <italic>MAM</italic> loci evolved three tandem genes encoding enzymes responsible for the biosynthesis of aliphatic glucosinolates with different carbon chain-lengths. In lineage II species, the <italic>MAM</italic> loci encode enzymes responsible for the biosynthesis of short-chain aliphatic glucosinolates. Our proposed model of the evolutionary pathway of <italic>MAM</italic> genes will be useful for understanding the specific function of these genes in Brassicaceae species.</p>