You Lu-Peng, Miao Jing, Zou Ai-Lan, Qi Jin-Liang, Yang Yong-Hua
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
Yi Chuan. 2012 Apr;34(4):485-94. doi: 10.3724/sp.j.1005.2012.00485.
Rpi-blb2, which is originally derived from Solanum bulbocastanum, is a broad-spectrum potato late blight resistance gene and belongs to the NBS-LRR family. Here, the LRR homologues of Rpi-blb2 were cloned with PCR method from 40 potato cultivars (including 20 resistant potato cultivars and 20 susceptible ones) and 7 wild potato populations. Then, the similarities of the sequences, polymorphic (segregating) sites, and nucleotide diversities were estimated by bioinformatic methods. The results showed that high nucleotide polymorphism and some hot-spot mutations existed in the LRR region of Rpi-blb2. The test of Ka/Ks ratio showed that the function of LRR was conserved because of the purifying selection, although different positions of the Rpi-blb2 LRR region were under different selection pressures. Moreover, the LRR region of Rpi-blb2 had no clear differentiation between the cultivated and wild potatoes.
Rpi-blb2最初源自马铃薯，是一种广谱抗马铃薯晚疫病基因，属于NBS-LRR家族。在此，采用PCR方法从40个马铃薯品种（包括20个抗病马铃薯品种和20个感病品种）和7个野生马铃薯群体中克隆了Rpi-blb2的LRR同源物。然后，通过生物信息学方法估计了序列的相似性、多态性（分离）位点和核苷酸多样性。结果表明，Rpi-blb2的LRR区域存在高核苷酸多态性和一些热点突变。Ka/Ks比值测试表明，由于纯化选择，LRR的功能得以保守，尽管Rpi-blb2 LRR区域的不同位置受到不同的选择压力。此外，Rpi-blb2的LRR区域在栽培马铃薯和野生马铃薯之间没有明显分化。
