Zhu Weidong, Qian Jie, Hou Yingke, Tembrock Luke R, Nie Liyun, Hsu Yi-Feng, Xiang Yong, Zou Yi, Wu Zhiqiang
Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China.
Guangdong Laboratory for Lingnan Modern Agriculture, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
Plant Divers. 2024 Nov 9;47(1):127-135. doi: 10.1016/j.pld.2024.11.001. eCollection 2025 Jan.
Single-stranded DNA-binding proteins (SSBs) play essential roles in the replication, recombination and repair processes of organellar DNA molecules. In , SSBs are encoded by a small family of two genes ( and ). However, the functional divergence of these two copies in plants remains largely unknown, and detailed studies regarding their roles in the replication and recombination of organellar genomes are still incomplete. In this study, phylogenetic, gene structure and protein motif analyses all suggested that SSB1 and SSB2 probably diverged during the early evolution of seed plants. Based on accurate long-read sequencing results, and mutants had decreased copy numbers for both mitochondrial DNA (mtDNA) and plastid DNA (ptDNA), accompanied by a slight increase in structural rearrangements mediated by intermediate-sized repeats in mt genome and small-scale variants in both genomes. Our findings provide an important foundation for further investigating the effects of DNA dosage in the regulation of mutation frequencies in plant organellar genomes.
单链DNA结合蛋白（SSBs）在细胞器DNA分子的复制、重组和修复过程中发挥着重要作用。在[具体物种]中，SSBs由一个包含两个基因（[基因名称1]和[基因名称2]）的小家族编码。然而，这两个拷贝在植物中的功能差异在很大程度上仍不清楚，关于它们在细胞器基因组复制和重组中作用的详细研究仍不完整。在本研究中，系统发育、基因结构和蛋白质基序分析均表明，SSB1和SSB2可能在种子植物的早期进化过程中发生了分化。基于准确的长读长测序结果，[基因名称1]和[基因名称2]突变体的线粒体DNA（mtDNA）和质体DNA（ptDNA）拷贝数均减少，同时线粒体基因组中由中等大小重复序列介导的结构重排以及两个基因组中的小规模变异略有增加。我们的研究结果为进一步研究DNA剂量对植物细胞器基因组突变频率调控的影响提供了重要基础。
