State Key Laboratory of Tree Genetics and Breeding & Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
BMC Biol. 2024 Apr 12;22(1):82. doi: 10.1186/s12915-024-01875-4.
As an endemic shrub of the Qinghai-Tibetan Plateau (QTP), the distribution of Hippophae tibetana Schlecht. ranges between 2800 and 5200 m above sea level. As the most basal branch of the Hippophae genus, H. tibetana has an extensive evolutionary history. The H. tibetana is a valuable tree for studying the ecological evolution of species under extreme conditions.
Here, we generated a high-quality chromosome-level genome of H. tibetana. The total size of the assembly genome is 917 Mb. The phylogenomic analysis of 1064 single-copy genes showed a divergence between 3.4 and 12.8 Mya for H. tibetana. Multiple gene families associated with DNA repair and disease resistance were significantly expanded in H. tibetana. We also identified many genes related to DNA repair with signs of positive selection. These results showed expansion and positive selection likely play important roles in H. tibetana's adaptation to comprehensive extreme environments in the QTP. A comprehensive genomic and transcriptomic analysis identified 49 genes involved in the flavonoid biosynthesis pathway in H. tibetana. We generated transgenic sea buckthorn hairy root producing high levels of flavonoid.
Taken together, this H. tibetana high-quality genome provides insights into the plant adaptation mechanisms of plant under extreme environments and lay foundation for the functional genomic research and molecular breeding of H. tibetana.
沙棘是青藏高原特有的一种灌木，分布在海拔 2800 至 5200 米之间。作为沙棘属最原始的分支，西藏沙棘具有广泛的进化历史。西藏沙棘是研究物种在极端条件下生态进化的宝贵树种。
我们生成了高质量的西藏沙棘染色体水平基因组。组装基因组的总大小为 917 Mb。1064 个单拷贝基因的系统发育分析表明，西藏沙棘的分化时间在 3.4 到 12.8 百万年前。与 DNA 修复和疾病抗性相关的多个基因家族在西藏沙棘中显著扩张。我们还鉴定了许多与 DNA 修复相关的基因，这些基因具有正选择的迹象。这些结果表明扩张和正选择可能在西藏沙棘适应青藏高原综合极端环境中发挥了重要作用。综合基因组和转录组分析鉴定了 49 个与西藏沙棘类黄酮生物合成途径相关的基因。我们生成了产生高水平类黄酮的转沙棘毛状根。
总之，这个高质量的西藏沙棘基因组为我们提供了对植物在极端环境下适应机制的深入了解，并为西藏沙棘的功能基因组研究和分子育种奠定了基础。
