Hong Yongfeng, Huang Xia, Li Chunmei, Ruan Xiaoxian, Wang Zhen, Su Yingjuan, Wang Ting
School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Research Institute of Sun Yat-Sen, University in Shenzhen, Shenzhen 518057, China.
Plants (Basel). 2020 Nov 27;9(12):1665. doi: 10.3390/plants9121665.
, the only native congener of the invasive weed in China, is an ideal species for comparative study to reveal the invasion mechanism. However, its genome resources are lagging far behind its congener, which limits the comparative genomic analysis. Our goal is to characterize the genome of by next-generation sequencing and propose a scheme for long-read genome sequencing. Previous studies have shown that the genomic resources of the host plant would be affected by the endophytic microbial DNA. An aseptic sample of will ensure the proper genome in downstream analysis. Because endophytes are ubiquitous in the greenhouse-grown , the in vitro culture with cefotaxime or timentin treatment was undertaken to obtain the aseptic plantlets. The in vivo mother plant and in vitro plantlets were used to survey the genome. The microbial contamination in was recognized by blast search and eliminated from the raw reads. The decontaminated sequencing reads were used to predict the genome size, heterozygosity, and repetitive rate. The in vivo plant was so contaminated that microbes occupied substantial sequencing resources and misled the scaffold assembly. Compared with cefotaxime, treatment with timentin performed better in cultivating robust in vitro plantlets. The survey result from the in vitro plantlets was more accurate due to low levels of contamination. The genome size was estimated to be 1.80 Gb with 0.50% heterozygosity and 78.35% repetitive rate. Additionally, 289,831 SSRs were identified in the genome. The genome is heavily contaminated and repetitive; therefore, the in vitro culture technique and long-read sequencing technology are recommended to generate a high-quality and highly contiguous genome.
在中国,[物种名称]是入侵杂草的唯一本土同属物种,是揭示入侵机制的比较研究的理想物种。然而,其基因组资源远远落后于其同属物种,这限制了比较基因组分析。我们的目标是通过下一代测序对[物种名称]的基因组进行表征,并提出长读长基因组测序方案。先前的研究表明,宿主植物的基因组资源会受到内生微生物DNA的影响。[物种名称]的无菌样本将确保下游分析中基因组的准确性。由于内生菌在温室种植的[物种名称]中普遍存在,因此采用头孢噻肟或替门汀处理进行体外培养以获得无菌苗。使用体内母株和体外苗对基因组进行检测。通过比对搜索识别[物种名称]中的微生物污染,并从原始读数中去除。经净化的测序读数用于预测基因组大小、杂合度和重复率。体内植物污染严重,微生物占用了大量测序资源并误导了支架组装。与头孢噻肟相比,替门汀处理在培育健壮的体外苗方面表现更好。由于污染水平低,体外苗的检测结果更准确。估计基因组大小为1.80 Gb,杂合度为0.50%,重复率为78.35%。此外,在基因组中鉴定出289,831个简单序列重复(SSR)。该基因组污染严重且重复序列多;因此,建议采用体外培养技术和长读长测序技术来生成高质量和高度连续的基因组。