Grewe Felix, Edger Patrick P, Keren Ido, Sultan Laure, Pires J Chris, Ostersetzer-Biran Oren, Mower Jeffrey P
Center for Plant Science Innovation, University of Nebraska, Lincoln, NE 68588, USA; Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE 68583, USA.
Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA.
Mitochondrion. 2014 Nov;19 Pt B:135-43. doi: 10.1016/j.mito.2014.05.008. Epub 2014 Jun 4.
To elucidate the evolution of mitochondrial genomic diversity within a single order of angiosperms, we sequenced seven Brassicales genomes and the transcriptome of Brassica oleracea. In the common ancestor of Brassicaceae, several genes of known function were lost and the ccmFN gene was split into two independent genes, which also coincides with a trend of genome reduction towards the smallest sequenced angiosperm genomes of Brassica. For most ORFs of unknown function, the lack of conservation throughout Brassicales and the generally low expression and absence of RNA editing in B. oleracea argue against functionality. However, two chimeric ORFs were expressed and edited in B. oleracea, suggesting a potential role in cytoplasmic male sterility in certain nuclear backgrounds. These results demonstrate how frequent shifts in size, structure, and content of plant mitochondrial genomes can occur over short evolutionary time scales.
为阐明被子植物单一目内线粒体基因组多样性的演化，我们对七个十字花目基因组以及甘蓝的转录组进行了测序。在十字花科的共同祖先中，几个已知功能的基因丢失，ccmFN基因分裂成两个独立基因，这也与基因组朝着甘蓝最小测序被子植物基因组减少的趋势相吻合。对于大多数功能未知的开放阅读框（ORF），整个十字花目缺乏保守性，且甘蓝中普遍低表达且不存在RNA编辑，这表明它们不具有功能。然而，两个嵌合ORF在甘蓝中表达并发生编辑，表明在某些核背景下可能在细胞质雄性不育中发挥作用。这些结果证明了植物线粒体基因组在大小、结构和内容上的频繁变化是如何在短进化时间尺度上发生的。
