低温胁迫对黄瓜花叶病毒CMV-BG株系cp基因多态性的影响

研究了低温胁迫下黄瓜花叶病毒与三生烟互作后CMV cp基因序列的变化规律,并分析了植物RNA病毒的进化机制。用黄瓜花叶病毒北京甘蓝分离物(CMV-BG)侵染三生烟不同单株,置于不同温度条件下(常温和低温)培养30 d后,对CMV cp基因进行克隆、序列测定和多态性分析。结果表明,侵染低温组植物CMV的cp基因多态性(Pi=0.001 76)高于常温组(Pi=0.001 14),IFEL分析检测到低温组第48个氨基酸位点为正选择位点,初步表明低温胁迫有助于提高CMV-BG cp基因序列的多态性,温度胁迫是植物RNA病毒与宿主互作过程中基因序列变异的一种重要的作用力。

Cloning and sequence analysis of coat protein gene of Cucumber mosaic virus under low temperature stress

Aiming at studying CMV coat protein gene sequence variation and further analysis the evolutionary mechanism of plant RNA viruses upon low temperature stress, tobacco (Nicotiana tabacum var. Samsun NN) infected with cucumber mosaic virus isolate (CMV-BG) was planted under room temperature and low temperature for 30 d, and then the CMV cp gene was cloned and its sequence and polymorphism were analyzed. The results showed that cp gene polymorphism (Pi=0.001 76) in low-temperature group was higher than that in normal temperature group (Pi=0.001 14), and the 48^th amino acid site was a positive selection site in low-temperature group, detected by IFEL. It showed that low temperature stress can improve the CMV-BG cp gene polymorphism, and it is an important force for gene sequence evolution of RNA viruses during the interaction between the host and the virus.