Gao Kai, Guo Ting, An Xinmin
Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, Zhejiang, 311400, China.
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
BMC Genomics. 2025 Jan 9;26(1):23. doi: 10.1186/s12864-024-11184-3.
Populus tomentosa, known as Chinese white poplar, is indigenous and distributed across large areas of China, where it plays multiple important roles in forestry, agriculture, conservation, and urban horticulture. However, limited accessibility to the mitochondrial (mt) genome of P. tomentosa impedes phylogenetic and population genetic analyses and restricts functional gene research in Salicaceae family.
Single-molecule real-time (SMRT) sequencing technology was used to sequence, assemble, and annotate the mt genome of P. tomentosa. This genome has a complex structure composed of four circular molecules ranging from 153,004 to 330,873 base pairs (bp). Each of these four circular molecules contains unique gene sequences that constitute the mt genome of P. tomentosa. The mt genome comprises 69 functional genes, including 38 protein-coding genes (PCGs), 26 tRNA genes, and 5 rRNA genes. After removing duplications, 19 different tRNA coding genes remain, though only 10 amino acids can be recognized. The noncoding region constitutes 93.38% of the mt genome, comprising a large number of repetitive sequences, gene spacer regions, and insertion from chloroplast sequences. Specifically, 40 chloroplast-derived sequences, with a total length of 24,381 bp, were identified in P. tomentosa.
In the current study, the results provide mitochondrial genomic evidence for the maternal origin of P. tomentosa and enhance understanding of the gene dialog between organelle genomes, contributing to the conservation and utilization of the genetic resources of P. tomentosa.
毛白杨，又称中国白杨树，原产于中国，分布广泛，在林业、农业、生态保护和城市园艺等多个领域发挥着重要作用。然而，毛白杨线粒体（mt）基因组难以获取，这阻碍了系统发育和群体遗传学分析，并限制了杨柳科功能基因的研究。
采用单分子实时（SMRT）测序技术对毛白杨的mt基因组进行测序、组装和注释。该基因组结构复杂，由四个环状分子组成，长度从153,004到330,873碱基对（bp）不等。这四个环状分子中的每一个都包含独特的基因序列，构成了毛白杨的mt基因组。mt基因组包含69个功能基因，包括38个蛋白质编码基因（PCG）、26个tRNA基因和5个rRNA基因。去除重复序列后，仍有19个不同的tRNA编码基因，尽管只能识别10种氨基酸。非编码区占mt基因组的93.38%，包含大量重复序列、基因间隔区和来自叶绿体序列的插入片段。具体而言，在毛白杨中鉴定出40个叶绿体衍生序列，总长度为24,381 bp。
在本研究中，研究结果为毛白杨的母系起源提供了线粒体基因组证据，并增进了对细胞器基因组间基因对话的理解，有助于毛白杨遗传资源的保护和利用。
