Shandong Institute of Pomology, Taian, 271000, Shandong, China.
Shandong Academy of Agricultural Sciences, Jinan, 250100, Shandong, China.
BMC Plant Biol. 2023 Oct 25;23(1):512. doi: 10.1186/s12870-023-04538-8.
Punica granatum is a fundamentally important fruit tree that has important economic, medicinal and ornamental properties. At present, there are few reports on the mitochondrial genome of pomegranate. Hence, in this study the P. granatum mitogenome was sequenced and assembled to further understanding of organization, variation, and evolution of mitogenomes of this tree species.
The genome structure was multi-chromosomes with seven circular contigs, measuring 382,774 bp in length with a 45.91% GC content. It contained 74 genes, including 46 protein-coding genes, 25 tRNA genes, and three rRNA genes. There were 188 pairs of dispersed repeats with lengths of 30 or greater, primarily consisting of reverse complementary repeats. The mitogenome analysis identified 114SSRs and 466 RNA editing sites. Analyses of codon usage, nucleotide diversity and gene migration from chloroplast to mitochondrial were also conducted. The collinear and comparative analysis of mitochondrial structures between P. granatum and its proximal species indicated that P. granatum 'Taishanhong' was closely related to P. granatum 'Qingpitian' and Lagerstroemia indica. Phylogenetic examination based on the mitogenome also confirmed the evolutionary relationship.
The results offered crucial information on the evolutionary biology of pomegranate and highlighted ways to promote the utilization of the species' germplasm.
石榴是一种具有重要经济、药用和观赏价值的重要果树。目前，关于石榴的线粒体基因组的报道较少。因此，本研究对石榴的线粒体基因组进行了测序和组装，以进一步了解该树种线粒体基因组的组织、变异和进化。
基因组结构为多染色体，由七个环状连续体组成，长度为 382774bp，GC 含量为 45.91%。它包含 74 个基因，包括 46 个蛋白质编码基因、25 个 tRNA 基因和 3 个 rRNA 基因。有 188 对长度为 30 个或更长的分散重复序列，主要由反向互补重复序列组成。线粒体基因组分析确定了 114 个 SSRs 和 466 个 RNA 编辑位点。还进行了密码子使用、核苷酸多样性和叶绿体到线粒体基因迁移的分析。线粒体结构的共线性和比较分析表明，石榴‘泰山红’与石榴‘青皮甜’和紫薇关系密切。基于线粒体基因组的系统发育分析也证实了进化关系。
这些结果为石榴的进化生物学提供了重要信息，并为促进该物种种质资源的利用提供了途径。
