title: Genome of Plant Maca (Lepidium meyenii) Illuminates Genomic Basis for High-Altitude Adaptation in the Central Andes.
abstract: Maca (Lepidium meyenii Walp, 2n = 8x = 64), belonging to the Brassicaceae family, is an economic plant cultivated in the central Andes sierra in Peru (4000-4500 m). Considering that the rapid uplift of the central Andes occurred 5-10 million years ago (Ma), an evolutionary question arises regarding how plants such as maca acquire high-altitude adaptation within a short geological period. Here, we report the high-quality genome assembly of maca, in which two closely spaced maca-specific whole-genome duplications (WGDs; ∼6.7 Ma) were identified. Comparative genomic analysis between maca and closely related Brassicaceae species revealed expansions of maca genes and gene families involved in abiotic stress response, hormone signaling pathway, and secondary metabolite biosynthesis via WGDs. The retention and subsequent functional divergence of many duplicated genes may account for the morphological and physiological changes (i.e., small leaf shape and self-fertility) in maca in a high-altitude environment. In addition, some duplicated maca genes were identified with functions in morphological adaptation (i.e., LEAF CURLING RESPONSIVENESS) and abiotic stress response (i.e., GLYCINE-RICH RNA-BINDING PROTEINS and DNA-DAMAGE-REPAIR/TOLERATION 2) under positive selection. Collectively, the maca genome provides useful information to understand the important roles of WGDs in the high-altitude adaptation of plants in the Andes.
authors.affiliation: College of Life Science, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory of Pu-erh Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Pu'er Institute of Pu-erh Tea, Pu'er 665000, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Yan
authors.affiliation: Yunnan Research Center on Good Agricultural Practice for Dominant Chinese Medicinal Materials, Yunnan Agricultural University, Kunming 650201, China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: School of Science and Information Engineering, Yunnan Agricultural University, Kunming 650201, China.
authors.forename: Jiajin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Pu-erh Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Ma
authors.affiliation: College of Life Science, Kunming University of Science and Technology, Kunming 650504, China.
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Tan
authors.affiliation: College of Life Science, Kunming University of Science and Technology, Kunming 650504, China.
authors.forename: Ni
authors.initials: N
authors.lastname: Long
authors.affiliation: College of Life Science, Kunming University of Science and Technology, Kunming 650504, China.
authors.forename: Yangzi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Life Science, Kunming University of Science and Technology, Kunming 650504, China.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Public Technical Service Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
authors.forename: Yuqi
authors.initials: Y
authors.lastname: He
authors.affiliation: College of Life Science, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Yunnan University, Kunming 650091, China.
authors.forename: Shumei
authors.initials: S
authors.lastname: Hao
authors.affiliation: Yunnan Research Center on Good Agricultural Practice for Dominant Chinese Medicinal Materials, Yunnan Agricultural University, Kunming 650201, China.
authors.forename: Shengchao
authors.initials: S
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.affiliation: Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: fafuzhang@163.com.
authors.forename: Liangsheng
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Life Science, Kunming University of Science and Technology, Kunming 650504, China; Yunnan Research Institute for Local Plateau Agriculture and Industry, Kunming 650201, China. Electronic address: loyalyang@163.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Key Laboratory of Pu-erh Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China; Yunnan Research Institute for Local Plateau Agriculture and Industry, Kunming 650201, China. Electronic address: wchenntr@gmail.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: College of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory of Pu-erh Tea Science, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China; Pu'er Institute of Pu-erh Tea, Pu'er 665000, China. Electronic address: shengj@ynau.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Sheng
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics / Q000502:physiology; D000531:Altitude; D018745:Genome, Plant / Q000235:genetics*; D029686:Lepidium / Q000235:genetics* / Q000502:physiology; D010568:Peru; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology
keywords: Brassicaceae; Lepidium; genome sequencing; high-altitude adaptation; leaf morphogenesis; self-incompatibility; whole-genome duplication