Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium.
Center for Plant Systems Biology, VIB, B-9052 Ghent, Belgium.
Plant Cell. 2017 Nov;29(11):2786-2800. doi: 10.1105/tpc.17.00531. Epub 2017 Oct 25.
Gene and genome duplications have been rampant during the evolution of flowering plants. Unlike small-scale gene duplications, whole-genome duplications (WGDs) copy entire pathways or networks, and as such create the unique situation in which such duplicated pathways or networks could evolve novel functionality through the coordinated sub- or neofunctionalization of its constituent genes. Here, we describe a remarkable case of coordinated gene expression divergence following WGDs in We identified a set of 92 homoeologous gene pairs that all show a similar pattern of tissue-specific gene expression divergence following WGD, with one homoeolog showing predominant expression in aerial tissues and the other homoeolog showing biased expression in tip-growth tissues. We provide evidence that this pattern of gene expression divergence seems to involve genes with a role in cell polarity and that likely function in the maintenance of cell wall integrity. Following WGD, many of these duplicated genes evolved separate functions through subfunctionalization in growth/development and stress response. Uncoupling these processes through genome duplications likely provided important adaptations with respect to growth and morphogenesis and defense against biotic and abiotic stress.
基因和基因组倍增在开花植物的进化过程中一直很猖獗。与小规模的基因倍增不同，全基因组倍增（WGD）会复制整个途径或网络，从而创造出这样一种独特的情况，即这些复制的途径或网络可以通过其组成基因的协调亚功能化或新功能化来产生新的功能。在这里，我们描述了 WGD 后基因表达趋异的一个显著案例。我们鉴定了一组 92 对同源基因对，它们在 WGD 后都表现出相似的组织特异性基因表达趋异模式，其中一个同源基因对在地上组织中表现出主要表达，而另一个同源基因对在尖端生长组织中表现出偏倚表达。我们提供的证据表明，这种基因表达趋异模式似乎涉及与细胞极性相关的基因，这些基因可能在维持细胞壁完整性方面发挥作用。WGD 后，许多这些复制的基因通过生长/发育和应激反应的亚功能化而进化出了不同的功能。通过基因组倍增来分离这些过程可能为生长和形态发生以及抵御生物和非生物胁迫提供了重要的适应。
