Genome evolution of the psammophyte <i>Pugionium</i> for desert adaptation and further speciation
Quanjun Hu, Yazhen Ma, Terezie Mandáková, Sheng Shi, Chunlin Chen, Pengchuan Sun, Lei Zhang, Landi Feng, Yudan Zheng, Xiaoqin Feng, Wenjie Yang, Jiebei Jiang, Ting Li, Pingping Zhou, Qiushi Yu, Dongshi Wan, Martin A. Lysák, Zhenxiang Xi, Eviatar Nevo, Jianquan Liu
Abstract
(Brassicaceae). Our results indicated that this bispecific genus had undergone an allopolyploid event, and the two parental genomes were derived from two ancestral lineages with different chromosome numbers and structures. The postpolyploid expansion of gene families related to abiotic stress responses and lignin biosynthesis facilitated environmental adaptations of the genus to desert habitats. Population genomic analyses of both species further revealed their recent divergence with continuous gene flow, and the most divergent regions were found to be centered on three highly structurally reshuffled chromosomes. Genes under selection in these regions, which were mainly located in one of the two subgenomes, contributed greatly to the interspecific divergence in microhabitat adaptation.