《自然》（Nature)雜志3月24日在線發(fā)表了有關小麥A基因組測序的研究論文,。該研究首次完成了小麥A基因組的測序和草圖繪制,，對未來深入和系統(tǒng)研究麥類植物結(jié)構(gòu)與功能基因組學,，以及進一步推動栽培小麥的遺傳改良具有重要意義。這項研究由中科院遺傳與發(fā)育生物學研究所植物細胞與染色體工程國家重點實驗室小麥研究團隊發(fā)起,，通過與深圳華大基因研究院和美國加州大學戴維斯分校合作完成,。
小麥是全球最重要的糧食作物。廣泛種植的普通小麥是一個異源六倍體,，含有A,、B和D三個基因組。追本溯源,，普通小麥是由祖先野生的一粒小麥（烏拉爾圖小麥,，含AA基因組）與擬斯卑爾托山羊草雜交形成四倍體小麥。大約在8000年前,，四倍體小麥與粗山羊草再一次自然雜交,，經(jīng)自然和人類的選擇形成如今廣泛栽培的普通小麥。由于普通小麥基因組大而復雜（是水稻基因組的40倍）,，85%以上序列為重復序列,，致使基因組測序研究進展緩慢。
研究團隊利用新一代測序技術,，對二倍體烏拉爾圖小麥G1812系的基因組進行測序,、組裝、注釋及相關分析,。鑒定出34,879個編碼蛋白基因,，與已知禾本科作物基因組比較分析，鑒定出3,425個A基因組特異基因和24個新小RNA,，并發(fā)現(xiàn)含NB-ARC功能域的抗病基因在小麥A基因組明顯增多,。通過同源基因的比對和關聯(lián)分析，還鑒定出一批控制重要農(nóng)藝性狀的基因,。此外,，該研究還篩選出大量遺傳分子標記，將有助于重要數(shù)量農(nóng)藝形狀基因的克隆及基因組選擇,，促進小麥的分子育種,。
有關專家指出，這項成果將為研究小麥馴化史提供一個全新的視角,，并為多倍體小麥基因組的測序分析提供二倍體基因組參照序列,。注釋出的基因信息和分子標記有助于加速小麥的遺傳改良,，對保障糧食安全和農(nóng)業(yè)可持續(xù)發(fā)展具有重要作用。(生物谷Bioon.com)
doi:10.1038/nature11997
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Draft genome of the wheat A-genome progenitor Triticum urartu
Hong-Qing Ling, Shancen Zhao, Dongcheng Liu,Junyi Wang, Hua Sun, Chi Zhang, Huajie Fan, Dong Li, Lingli Dong, Yong Tao, Chuan Gao, Huilan Wu, Yiwen Li, Yan Cui, Xiaosen Guo, Shusong Zheng, Biao Wang, Kang Yu, Qinsi Liang, Wenlong Yang, Xueyuan Lou, Jie Chen, Mingji Feng, Jianbo Jian, Xiaofei Zhang, Guangbin Luo, Ying Jiang, Junjie Liu, Zhaobao Wang, Yuhui Sha, Bairu Zhang, Huajun Wu, Dingzhong Tang, Qianhua Shen, Pengya Xue, Shenhao Zou, Xiujie Wang, Xin Liu, Famin Wang, Yanping Yang, Xueli An, Zhenying Dong, Kunpu Zhang, Xiangqi Zhang, Ming-Cheng Luo, Jan Dvorak, Yiping Tong, Jian Wang, Huanming Yang, Zhensheng Li, Daowen Wang, Aimin Zhang & Jun Wang, Show fewer authors.
Bread wheat (Triticum aestivum, AABBDD) is one of the most widely cultivated and consumed food crops in the world. However, the complex polyploid nature of its genome makes genetic and functional analyses extremely challenging. The A?genome, as a basic genome of bread wheat and other polyploid wheats, for example, T. turgidum (AABB), T. timopheevii (AAGG) and T. zhukovskyi (AAGGAmAm), is central to wheat evolution, domestication and genetic improvement1. The progenitor species of the A?genome is the diploid wild einkorn wheat T.?urartu2, which resembles cultivated wheat more extensively than do Aegilops speltoides (the ancestor of the B genome3) and Ae. tauschii (the donor of the D genome4), especially in the morphology and development of spike and seed. Here we present the generation, assembly and analysis of a whole-genome shotgun draft sequence of the T.?urartu genome. We identified protein-coding gene models, performed genome structure analyses and assessed its utility for analysing agronomically important genes and for developing molecular markers. Our T.?urartu genome assembly provides a diploid reference for analysis of polyploid wheat genomes and is a valuable resource for the genetic improvement of wheat.
