添加卫星RNA对黄瓜花叶病毒寄主反应及其在系统寄主中含量的影响  

EFFECTS OF AN INDUCED SATELLITE RNA OF CUCUMBER MOSAIC VIRUS ON THE HOST REACTIONS OF ITS HELPER VIRUS AND VIRUS LOADING IN SYSTEMIC HOSTS

作　　者：陈集双[1] 金波[1] 覃玥[2] 杜志游[1] 陈绍宁[1] 柴立红[3] 陈子元[3] 

机构地区：[1]浙江理工大学生物工程研究所,浙江杭州310018 [2]浙江大学生命科学学院,浙江杭州310029 [3]浙江大学原子核农业科学研究所,浙江杭州310029

出　　处：《核农学报》2006年第3期181-186,235,共7页Journal of Nuclear Agricultural Sciences

基　　金：国家自然科学基金资助(30270744);浙江省科技厅院士基金(2004)资助

摘　　要：为了解卫星RNA(satRNA)对辅助病毒在系统寄主中的直接影响,将1株黄瓜花叶病毒(Cucumbermosaic virus,CMV)的卫星RNA(satRNA)sat-Yi与本身不携带卫星RNA的CMV分离物CNa在体外进行假重组,获得了人工构建的假重组毒株CMV-NY。通过寄主反应测定、双链RNA分析和全序列分析,显示satYi与CMV-CNa基因组RNA能够稳定共存,经过反复转接也没有发现卫星RNA的序列突变。通过测定CMV-CNa和NY这2个病毒株的寄主反应,发现satRNA-Yi的存在明显延迟了CNa在所有供试寄主中的发病时间,而且明显减弱了其在多数供试寄主上的症状表现,其中在葫芦科植物上表现出减轻症状的效果最明显;用一种新建的核酸玻片杂交方法,定量测定寄主植物中CMV基因组CP基因及卫星RNA的相对含量变化,结果显示:26℃条件下,在接种5、10、15、20、25和30d的心叶烟中,2个毒株的CP基因含量都呈下降趋势,在相应的时间内,NY-CP基因在同一寄主中的含量均低于CNa-CP基因的含量;接种10d,NY与CNa的寄主适应性没有显著差异,二者基因组CP基因在6种寄主植物中的相对含量均为番茄>假酸浆>心叶烟>西葫芦>南瓜>曼陀罗。由此得出以下结论:sat-Yi降低了CMV CP基因在寄主中的含量,且随着接种时间的增加,卫星RNA的影响作用越明显;sat-Yi不改变CMV基因组RNA的寄主适应性,但是通过降低CP基因含量改变其症状特征。For studying the relationship between satellite RNA （satRNA） and cucumber mosaic virus （CMV）, as its helper virus, a 369nt satRNA-Yi was transcribed in vitro and co-inoculated onto Nicotiana glotinosa plants with genomic RNAs of CMV-CNa, which contains no satellite RNA. A new strain （NY） of pseudo-recombinant was thus formed. By double stranded RNA analysis and sequence determination, the additional satellite RNA in the new strain was found co-existent continuously with genomic RNAs of the helper virus, and no mutation occurred during the pseudo-recombination and co-translation onto different host plants. These two strains were then inoculated onto host plants respectively, and investigated with respect to plant symptoms. On most host plants, disease symptoms induced by CMV-CNa were attenuated by adding sat RNA-Yi, especially on Cucurbita pepo. The relative RNA loadings （RRL） of coat protein （CP） gene and satRNA were quantitatively measured from the systemically infected host tissues, utilizing a method of RNA dot blot hybridization on glass slides. Under the controlled condition at 26℃, CNa and NY were inoculated onto 6 host plants and examined at 5, 10, 15, 20, 25, 30d post inoculation （dpi）, respectively. On N. glutinosa, the RRLs of CP gene of both strain and the satellite RNA of NY showed declining trends during the tested period, but the RRL of CP gene of CNa was always higher than that of NY. At 10 dpi, the RRLs of CP gene of CNa and NY differed obviously on all the hosts tested, but they were in the same order of host fitness, as the following： Lycopersicon esculentum 〉 Nicandra physanodes 〉 N. glutinosa 〉 Cucurbita pepo 〉 C. moschata 〉Datura stramonium. Meanwhile, the RRL order of satellite RNA was N. physanodes 〉 N. glutinosa 〉 L. esculentum 〉 D. stramonium 〉 C. pepo 〉 C. moschata. These results indicated that satRNA-Yi decreased the RRL of genomic RNA of CNa on systemic hosts. With inoculating time extending on, the effect of satRNA-Yi on CMV kept increas

关 键 词：黄瓜花叶病毒 卫星RNA 假重组 相互作用 定量测定 

分 类 号：S436.421[农业科学—农业昆虫与害虫防治]