Institut National de la Recherche Agronomique/Université Blaise Pascal, Unité Mixte de Recherche 1095, Génétique, Diversité et Ecophysiologie des Céréales, Clermont Ferrand, France.
Plant Cell. 2012 May;24(5):1776-92. doi: 10.1105/tpc.112.095752. Epub 2012 May 15.
The recent availability of plant genome sequences, combined with a robust evolutionary scenario of the modern monocot and eudicot karyotypes from their diploid ancestors, offers an opportunity to gain insights into microRNA (miRNA) gene paleohistory in plants. Characterization and comparison of miRNAs and associated protein-coding targets in plants allowed us to unravel (1) contrasted genome conservation patterns of miRNAs in monocots and eudicots after whole-genome duplication (WGD), (2) an ancestral miRNA founder pool in the monocot genomes dating back to 100 million years ago, (3) miRNA subgenome dominance during the post-WGD diploidization process with selective miRNA deletion complemented with possible transposable element-mediated return flows, and (4) the miRNA/target interaction-directed differential loss/retention of miRNAs following the gene dosage balance rule. Together, our data suggest that overretained miRNAs in grass genomes may be implicated in connected gene regulations for stress responses, which is essential for plant adaptation and useful for crop variety innovation.
近年来，植物基因组序列的可用性，加上现代单子叶植物和真双子叶植物核型从其二倍体祖先的稳健进化情景，为深入了解植物中 microRNA (miRNA) 基因的古生物学提供了机会。对植物中的 miRNA 和相关的编码蛋白靶标进行的特征描述和比较，使我们能够揭示：（1）在全基因组加倍 (WGD) 之后，单子叶植物和真双子叶植物中 miRNA 的对比性基因组保守模式；（2）在 1 亿年前的单子叶植物基因组中存在一个祖先 miRNA 创始池；（3）在 WGD 后二倍体化过程中 miRNA 亚基因组的优势，伴随着选择性 miRNA 删除和可能的转座元件介导的回复流；（4）在遵循基因剂量平衡规则的情况下，miRNA/target 相互作用指导下 miRNA 的差异丢失/保留。总的来说，我们的数据表明，草基因组中过度保留的 miRNA 可能与应激反应的相关基因调控有关，这对植物的适应至关重要，对作物品种创新也很有用。
