Kim Saet-Byul, Kang Won-Hee, Huy Hoang Ngoc, Yeom Seon-In, An Jeong-Tak, Kim Seungill, Kang Min-Young, Kim Hyun Jung, Jo Yeong Deuk, Ha Yeaseong, Choi Doil, Kang Byoung-Cheorl
Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Korea.
Department of Horticulture, Institute of Agriculture & Life Science, Gyeongsang National University, Jinju, 660-701, Korea.
New Phytol. 2017 Jan;213(2):886-899. doi: 10.1111/nph.14177. Epub 2016 Sep 9.
Plants have evolved hundreds of nucleotide-binding and leucine-rich domain proteins (NLRs) as potential intracellular immune receptors, but the evolutionary mechanism leading to the ability to recognize specific pathogen effectors is elusive. Here, we cloned Pvr4 (a Potyvirus resistance gene in Capsicum annuum) and Tsw (a Tomato spotted wilt virus resistance gene in Capsicum chinense) via a genome-based approach using independent segregating populations. The genes both encode typical NLRs and are located at the same locus on pepper chromosome 10. Despite the fact that these two genes recognize completely different viral effectors, the genomic structures and coding sequences of the two genes are strikingly similar. Phylogenetic studies revealed that these two immune receptors diverged from a progenitor gene of a common ancestor. Our results suggest that sequence variations caused by gene duplication and neofunctionalization may underlie the evolution of the ability to specifically recognize different effectors. These findings thereby provide insight into the divergent evolution of plant immune receptors.
植物已经进化出数百种核苷酸结合和富含亮氨酸结构域蛋白（NLRs）作为潜在的细胞内免疫受体，但导致识别特定病原体效应子能力的进化机制仍不清楚。在这里，我们通过基于基因组的方法，利用独立分离群体克隆了Pvr4（辣椒中的一种马铃薯Y病毒抗性基因）和Tsw（中国辣椒中的一种番茄斑萎病毒抗性基因）。这两个基因都编码典型的NLRs，并且位于辣椒10号染色体的同一位置。尽管这两个基因识别完全不同的病毒效应子，但它们的基因组结构和编码序列却惊人地相似。系统发育研究表明，这两种免疫受体是从一个共同祖先的祖基因分化而来的。我们的结果表明，基因复制和新功能化引起的序列变异可能是特异性识别不同效应子能力进化的基础。这些发现从而为植物免疫受体的趋异进化提供了见解。
