Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China.
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China
Plant Physiol. 2018 May;177(1):82-89. doi: 10.1104/pp.18.00185. Epub 2018 Mar 21.
During plant-pathogen interactions, plants use intracellular proteins with nucleotide-binding site and Leu-rich repeat (NBS-LRR) domains to detect pathogens. NBS-LRR proteins represent a major class of plant disease resistance genes (-genes). Whereas -genes have been well characterized in angiosperms, little is known about their origin and early diversification. Here, we perform comprehensive evolutionary analyses of -genes in plants and report the identification of -genes in basal-branching streptophytes, including charophytes, liverworts, and mosses. Phylogenetic analyses suggest that plant -genes originated in charophytes and R-proteins diversified into TIR-NBS-LRR proteins and non-TIR-NBS-LRR proteins in charophytes. Moreover, we show that plant R-proteins evolved in a modular fashion through frequent gain or loss of protein domains. Most of the -genes in basal-branching streptophytes underwent adaptive evolution, indicating an ancient involvement of -genes in plant-pathogen interactions. Our findings provide novel insights into the origin and evolution of -genes and the mechanisms underlying colonization of terrestrial environments by plants.
在植物-病原体相互作用中，植物利用具有核苷酸结合位点和富含亮氨酸重复（NBS-LRR）结构域的细胞内蛋白来检测病原体。NBS-LRR 蛋白代表了植物抗病基因（-genes）的主要类别。虽然 -genes 在被子植物中得到了很好的描述，但它们的起源和早期多样化知之甚少。在这里，我们对植物中的 -genes 进行了全面的进化分析，并报告了在基础分支的绿藻门中鉴定出的 -genes，包括轮藻、苔藓和藓类植物。系统发育分析表明，植物 -genes 起源于绿藻门，而 R 蛋白在绿藻门中多样化为 TIR-NBS-LRR 蛋白和非 TIR-NBS-LRR 蛋白。此外，我们表明植物 R 蛋白通过频繁获得或丧失蛋白结构域而以模块化方式进化。基础分支的绿藻门中的大多数 -genes 经历了适应性进化，表明 -genes 很早就参与了植物-病原体的相互作用。我们的研究结果为 -genes 的起源和进化以及植物对陆地环境的殖民化提供了新的见解。
