番茄斑驳花叶病毒在主要茄科作物上的发生及其致病机理

Tomato mottle mosaic virus (ToMMV) was recently identified as a tentative member in the genus Tobamovirus, which was firstly detected from tomato in Mexico. ToMMV was also detected from pepper in Yunnan, Tibet and Hunan in China. At present, little research work has been conducted about ToMMV worldwide, especially for its biological characteristics and pathogenicity. On the basis of our previous research works, this research proposal intends to establish rapid, specific and sensitive detection techniques for ToMMV, then detect ToMMV from pepper, tomato, potato and tobacco plants collected from the major Solanaceae crop production areas to explore the occurrence and distribution of ToMMV in China. The transmission ways, host range of ToMMV also will be tested to evaluate the potential risks about the disease caused by ToMMV in China. At the same time, the key factors associated with the infectivity, pathogenicity or host range of ToMMV will be identified with the virus infectious clone to reveal the molecular mechanism of ToMMV pathogenicity. Research results will benefit for preventing the spread of ToMMV to more areas and crops, for providing theoretical basis and technical guidance for the prediction, monitoring and effective control of the disease caused by ToMMV. Research results might promote the further studies on the genome functions about ToMMV in the future.

番茄斑驳花叶病毒（ToMMV）是近期在国外番茄上鉴定的烟草花叶病毒属一种新病毒，我国云南、西藏和湖南的辣椒上也检测到了ToMMV的发生。目前国内外对ToMMV知之甚少，其生物学特性和致病性方面的研究基本未见报道。本项目拟在前期研究工作基础上，利用生物学、血清学和分子生物学等手段，建立ToMMV快速、特异、灵敏的检测技术，对茄科作物辣椒、番茄、马铃薯和烟草展开ToMMV的普查和检测，探明其在我国的发生为害情况，明确其传播途径，鉴定其寄主范围，对ToMMV在我国的潜在危害性和风险性进行分析。同时利用病毒侵染性克隆，对ToMMV与侵染性、致病性、寄主范围等相关因子进行鉴定，解析ToMMV致病性的分子机理。研究结果将为及时阻断ToMMV向更多的地区和作物扩散，为ToMMV引起的病毒病进行预报、监测及有效防控提供坚实的理论基础和技术指导，并为进一步深入分析ToMMV的基因组功能奠定基础。

番茄斑驳花叶病毒（ToMMV）是烟草花叶病毒属的一个新种，国内外对其生物学和分子生物学的研究甚少。本项目的研究工作，发现目前ToMMV已在我国云南、湖南、海南、辽宁、陕西、西藏和内蒙古等7个省区的辣椒和番茄上发生，并首次在豌豆上发现ToMMV的侵染。ToMMV可通过摩擦、注射、种子和土壤进行传播；人工接种条件下，ToMMV在常见的茄科、十字花科、豆科和葫芦科作物上均可侵染。开展了ToMMV对主要番茄及辣椒品种的抗感性鉴定，筛选出了对ToMMV免疫的辣椒材料1份、高抗的辣椒材料2份；而供试的番茄材料均可感染ToMMV。分析了ToMMV侵染烟草的细胞病理特征，发现在被ToMMV感染的黄花烟和珊西烟细胞质中，均有多泡体结构和大量次级囊泡，存在髓鞘样结构和线粒体瓦解现象。建立了烟草花叶病毒属病毒的通用RT-PCR检测方法，至少可以检测到以侵染茄科、兰科和葫芦科为主的9种烟草花叶病毒属病毒，大大提高了烟草花叶病毒属病毒的检测效率。构建了ToMMV的侵染性cDNA克隆，并对ToMMV的致病因子开展了鉴定，发现ToMMV的P50可能是诱导烟草产生坏死的致病蛋白，MP可能是ToMMV的寄主决定因子，mp基因的nt5296-5664和nt5098-5163是寄主决定因子的两个关键功能域；CP可能是ToMMV的关键致病因子，cp基因的nt5767-5799、nt6074-6184可能是ToMMV侵染黄花烟和珊西烟中CP致病因子的两个关键功能域。通过高通量测序技术，初步分析了ToMMV侵染珊西烟后3个不同症状形成时期之间以及同一时期ToMMV侵染与未侵染对照之间差异性表达的相关miRNA。