College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China.
Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China.
Int J Mol Sci. 2022 Oct 6;23(19):11864. doi: 10.3390/ijms231911864.
Transferring the genome of distant species to crops is an efficient way to create new germplasms. However, the molecular mechanisms involved are unclear. In this study, a new rice restorer line R21 with heat tolerance was created by introgressing the genomic DNA of sorghum into the recipient restorer line Jin Hui 1. Assembly of rice R21 and Jin Hui 1 genomes was performed using PacBio sequencing technology. Comparative genome analysis and coverage statistics showed that the repetitive sequence atr0026 was a candidate introgression fragment of sorghum DNA. Sequence similarity analysis revealed that atr0026 was distributed at different copy numbers on the telomeric position of chromosomes 9 or 10 in R21, Jin Hui 1, and several rice varieties, indicating that the repetitive sequence from sorghum was highly conserved in rice. The repeat annotation in Gramineae indicated that ribosomal DNA loci that existed in atr0026 may be cause a rearrangement of chromosomes 9 and 10 of the R21 genome, resulting in a copy number variation at the 5' end of it. Our study lays the foundation for further elucidation of the molecular mechanisms underlying the heat tolerance of sorghum DNA introgression variant line R21, which is of great significance for guiding crop genetic breeding.
将远缘物种的基因组转移到作物中是创造新种质的有效方法。然而，涉及的分子机制尚不清楚。本研究通过将高粱基因组 DNA 导入受体恢复系金辉 1 中，创建了一个具有耐热性的新型水稻恢复系 R21。使用 PacBio 测序技术对水稻 R21 和金辉 1 基因组进行了组装。比较基因组分析和覆盖度统计表明，重复序列 atr0026 是高粱 DNA 插入片段的候选序列。序列相似性分析表明，atr0026 在 R21、金辉 1 和几种水稻品种的染色体 9 或 10 的端粒位置以不同的拷贝数分布，表明来自高粱的重复序列在水稻中高度保守。禾本科的重复注释表明，存在于 atr0026 中的核糖体 DNA 位点可能导致 R21 基因组 9 和 10 号染色体的重排，导致其 5'端的拷贝数发生变化。本研究为进一步阐明高粱 DNA 导入变异系 R21 耐热性的分子机制奠定了基础，对指导作物遗传育种具有重要意义。
