Gramzow Lydia, Theißen Günter
Matthias Schleiden Institute-Genetics, Friedrich Schiller University Jena, Jena, Germany.
Methods Mol Biol. 2019;1932:41-50. doi: 10.1007/978-1-4939-9042-9_3.
Plant microRNAs do not only perform important roles in development; they also have a fascinating evolutionary dynamics. Their genes appear to originate at quite a high rate during evolution, but most of them evolve initially in an almost neutral way and hence also get lost quite rapidly. Despite the high birth and death rate, a few miRNA-encoding genes got involved in the control of important target genes and thus have been conserved during evolution. This happened obviously at all times and taxonomic levels during land plant evolution. Consequently, the genomes of extant plant species contain a mix of miRNA-encoding genes of different ages, ranging from very young, often even species-specific loci to genes that had already been established in the stem group of extant land plants more than 400 million years ago. It could well be that the evolutionary dynamics of miRNA-encoding genes contributed substantially to the evolution of developmental plasticity in plants.
植物微小RNA不仅在植物发育过程中发挥重要作用，它们还具有引人入胜的进化动态。在进化过程中，它们的基因似乎以相当高的速率产生，但大多数基因最初以近乎中性的方式进化，因此也很快消失。尽管产生和消失的速率很高，但少数编码微小RNA的基因参与了对重要靶基因的调控，因此在进化过程中得以保留。在陆地植物进化的所有时期和分类水平上显然都是如此。因此，现存植物物种的基因组中包含了不同年代的编码微小RNA的基因，从非常年轻的、通常甚至是物种特异性的位点，到早在4亿多年前就已在现存陆地植物的干群中建立的基因。编码微小RNA的基因的进化动态很可能在很大程度上促进了植物发育可塑性的进化。
