PT  - JOURNAL ARTICLE
AU  - Jing Zhang
AU  - Yang Tian
AU  - Liang Yan
AU  - Guanghui Zhang
AU  - Xiao Wang
AU  - Yan Zeng
AU  - Jiajin Zhang
AU  - Xiao Ma
AU  - Yuntao Tan
AU  - Ni Long
AU  - Yangzi Wang
AU  - Yujin Ma
AU  - Yu Xue
AU  - Shumei Hao
AU  - Shengchao Yang
AU  - Wen Wang
AU  - Liangsheng Zhang
AU  - Yang Dong
AU  - Wei Chen
AU  - Jun Sheng
TI  - Genome of octoploid plant maca (<em>Lepidium meyenii</em>) illuminates genomic basis for high altitude adaptation in the central Andes
AID  - 10.1101/017590
DP  - 2015 Jan 01
TA  - bioRxiv
PG  - 017590
4099  - http://biorxiv.org/content/early/2015/04/06/017590.short
4100  - http://biorxiv.org/content/early/2015/04/06/017590.full
AB  - Maca (Lepidium meyenii Walp, 2n = 8× = 64) of Brassicaceae family is an Andean economic plant cultivated on the 4000-4500 meters central sierra in Peru. Considering the rapid uplift of central Andes occurred 5 to 10 million years ago (Mya), an evolutionary question arises on how plants like maca acquire high altitude adaptation within short geological period. Here, we report the high-quality genome assembly of maca, in which two close-spaced maca-specific whole genome duplications (WGDs, ∼ 6.7 Mya) were identified. Comparative genomics between maca and close-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. Retention and subsequent evolution of many duplicated genes may account for the morphological and physiological changes (i.e. small leaf shape and loss of vernalization) in maca for high altitude environment. Additionally, some duplicated maca genes under positive selection were identified with functions in morphological adaptation (i.e. MYB59) and development (i.e. GDPD5 and HDA9). Collectively, the octoploid maca genome sheds light on the important roles of WGDs in plant high altitude adaptation in the Andes.