PDF(Pubmed)
Abstract：
Plants rely on Nucleotide-binding, Leucine-rich repeat Receptors (NLRs) for pathogen recognition. Highly variable NLRs (hvNLRs) show remarkable intraspecies diversity, while their low-variability paralogs (non-hvNLRs) are conserved between ecotypes. At a population level, hvNLRs provide new pathogen-recognition specificities, but the association between allelic diversity and genomic and epigenomic features has not been established. Our investigation of NLRs in Arabidopsis Col-0 has revealed that hvNLRs show higher expression, less gene body cytosine methylation, and closer proximity to transposable elements than non-hvNLRs. hvNLRs show elevated synonymous and nonsynonymous nucleotide diversity and are in chromatin states associated with an increased probability of mutation. Diversifying selection maintains variability at a subset of codons of hvNLRs, while purifying selection maintains conservation at non-hvNLRs. How these features are established and maintained, and whether they contribute to the observed diversity of hvNLRs is key to understanding the evolution of plant innate immune receptors.
摘要：
植物依赖于核苷酸结合，用于病原体识别的富含亮氨酸重复受体(NLR)。高度可变的NLR（hvNLR）显示出显着的种内多样性，而它们的低变异性旁系同源物(非hvNLR)在生态型之间是保守的。在人口层面,hvNLR提供了新的病原体识别特异性，但是等位基因多样性与基因组和表观基因组特征之间的关联尚未确定。我们对拟南芥Col-0中NLR的研究表明，hvNLR显示出更高的表达，较少的基因体胞嘧啶甲基化，与非hvNLR相比，更接近转座因子。hvNLR显示升高的同义和非同义核苷酸多样性，并且处于与突变概率增加相关的染色质状态。多样化选择保持hvNLR密码子子集的可变性，而纯化选择保持非hvNLR的保守性。如何建立和维护这些功能，它们是否有助于观察到的hvNLR的多样性是理解植物先天免疫受体进化的关键。
