近日,在国家重点基础研究发展计划(973计划)和科技部科技支撑计划等项目支持下,中国科学院青岛生物能源与过程研究所周功克研究团队和兰州大学、华大基因公司等单位合作,在胡杨基因组及其抗逆机制研究领域取得重要进展(Genomic insights into salt adaptation in a desert poplar. Nature Communications, 2013),相关成果已在线发表于Nature杂志子刊Nature Communications。
树木森林具有较高的经济和生态环境价值,是世界上最丰富的纤维生物质资源之一,被广泛用于建筑、造纸和生物燃料等方面,但目前关于高盐胁迫下树木的基因组进化方面却知之甚少。胡杨(Populus euphratica Oliv.)是一种生长在中国西部盐碱不毛之地的独特树种, 其在高盐胁迫下仍能保持较快的生长速率和光合效率,耐盐浓度高达450mM。
作为世界上首次报道发现的耐盐胡杨基因组,该基因组与其具有紧密相关的同属中生代的毛白杨非常相似。同时,在胡杨中发现的一些参与耐盐的基因家族的成员在进化过程中出现多个重复复制现象。此外,与盐敏感的毛白杨基因组和转录组数据相比较,研究发现胡杨在响应盐胁迫的功能策略上呈现出富集大量正向选择(positive selection)的基因,它们中的一些基因在盐胁迫下表现显著上调。
根据上述研究结果,周功克等提出了胡杨可能的耐盐机制,为理解树木适应盐胁迫机制,加速林木的成材性和耐逆遗传工程改良等提供了重要研究基础。(生物谷Bioon.com)
生物谷推荐的英文摘要
Nature Communications DOI:10.1038/ncomms3797
Genomic insights into salt adaptation in a desert poplar
Tao Ma,Junyi Wang,Gongke Zhou,Zhen Yue,Quanjun Hu,Yan Chen,Bingbing Liu,Qiang Qiu,Zhuo Wang,Jian Zhang,Kun Wang,Dechun Jiang,Caiyun Gou,Lili Yu,Dongliang Zhan,Ran Zhou,Wenchun Luo,Hui Ma,Yongzhi Yang,Shengkai Pan
Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to salt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P. trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P. euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.