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新疆作为中国有名的瓜果之乡,其瓜类不仅成为其中最具代表性的品牌也日益成为农民增收致富的经济支柱产业。然而近年来由于新疆瓜果日益受到病毒病威胁,严重时造成大面积减产甚至绝收,大幅度制约了农民生产积极性和生活水平的提高。小西葫芦黄花叶病毒(Zucchini yellow mosaic virus,ZYMV)是其中比较具有代表性的病毒,为了对新疆不同主栽地区甜瓜(Cucumis melo)ZYMV进行生物防治和抗病毒甜瓜的研究。本研究利用同源克隆的方法,扩增获得了新疆19个样点ZYMV分离物衣壳蛋白(coat protein,CP)基因全长序列,ZYMV分离物CP基因全长介于1 080~1 180 bp,编码253~301个氨基酸,蛋白质大小约33 k D。序列比对发现,ZYMV核酸序列的3’和5’非编码区末端保守性较低,编码区及其周围序列保守性较高,氨基酸序列的N端保守性高于C端。ZYMV同源性比对结果发现,病毒属于同一ZYMV基因型。通过核酸序列构建的分子进化树可以将ZYMV分为4个亚组,亚组分离依据符合地区分布特性。根据对蛋白质理化性质,包括蛋白质的动力学、化学和热力学稳定性分析得出,ZYMV均属于稳定性蛋白。结合新疆夏季平均降水量和平均气温变化趋势发现,其与对应地区ZYMV CP的疏水性指数和脂溶性指数的变化趋势存在一定相关性。分析认为,不同地区ZYMV CP的稳定性存在一定的差异,这可能与新疆特殊的气候条件与分离物所处地理环境有关。本研究通过序列分析获得19个样点ZYMV CP核酸序列以及CP特征,为今后以RNA干扰技术或基因组编辑技术培育抗病毒甜瓜,进行生物农药研发等提供了基础的数据支持,同时为开展对植物病毒的致病机理以及探究环境与病毒传播机制的研究提供初期的研究方向。
As a well-known hometown of fruits and vegetables in China, Xinjiang is not only the most representative of its melons, but also an increasingly economic pillar of farmer income and prosperity. In recent years, however, Xinjiang’s fruits and vegetables are increasingly threatened by virus diseases. In severe cases, they have caused large-scale production cuts or even unparalleled harvests, significantly hampering peasants’ enthusiasm for production and raising living standards. Zucchini yellow mosaic virus (ZYMV) is one of the most representative viruses in this study. In order to study the biological control and antiviral melon of cucumber (Cucumis melo) ZYMV in different main planting areas in Xinjiang, In this study, the full-length sequence of the coat protein (CP) gene of 19 ZYMV isolates was amplified by homologous cloning. The full-length CP gene of ZYMV isolates ranged from 1 080 to 1 180 bp , Encoding 253 to 301 amino acids, the protein size of about 33 kD. Sequence alignment revealed that the 3 ’and 5’ non-coding regions of ZYMV were less conservative at the end of the coding region and conserved in the coding region and its surrounding regions. The N-terminal amino acid sequence of the ZYMV nucleic acid was more conservative than the C-terminus. ZYMV homology comparison results found that the virus belongs to the same ZYMV genotype. ZYMV can be divided into four subgroups according to the molecular phylogenetic tree constructed by nucleic acid sequences. The subgroups are separated according to the regional distribution characteristics. According to the physical and chemical properties of proteins, including protein kinetics, chemical and thermodynamic stability analysis, ZYMV belong to the stability of the protein. Based on the trend of average summer precipitation and average temperature in Xinjiang, it is found that there is a certain correlation between the changes of hydrophobic index and fat-soluble index of ZYMV CP in the corresponding area. The analysis shows that there are some differences in the stability of ZYMV CP in different areas, which may be related to the special climatic conditions in Xinjiang and the geographical environment in which the isolates are located. In this study, we obtained the nucleotide sequence of 19 ZYMV CPs and CP characteristics by sequence analysis, provided the basic data support for the future development of anti-virus melon by RNA interference technology or genome editing technology, and the development of biological pesticides. At the same time, The pathogenic mechanism of the virus and research on the environment and virus transmission provide initial research directions.