Hammond R W
Microbiology and Plant Pathology Laboratory, USDA-ARS, Beltsville, Maryland 20705.
Virology. 1992 Apr;187(2):654-62. doi: 10.1016/0042-6822(92)90468-5.
A series of nucleotide substitutions (G46----C; C47----A; C315----U; U317----C) were introduced into the virulence modulating region of the intermediate strain of potato spindle tuber viroid (PSTVd) in order to examine their effect upon viroid infectivity and pathogenicity with the presence of all four mutations resulting in the sequence of a previously reported severe strain of PSTVd. Eight of the resulting mutant cDNAs were characterized for infectivity and symptom induction in tomato, and the secondary structure of their corresponding RNAs was examined. The combined results of infectivity, computer analysis, and chemical mapping data imply that a previously proposed correlation between thermodynamic stability and PSTVd pathogenicity does not hold true in all cases and suggest that conformation and/or sequence-specific interactions with host factors play a role in symptom development.
一系列核苷酸替换（G46→C；C47→A；C315→U；U317→C）被引入到马铃薯纺锤块茎类病毒（PSTVd）中间株系的毒力调节区域，以研究它们对类病毒感染性和致病性的影响，所有四个突变的存在导致了先前报道的一种严重PSTVd株系的序列。对所得的八个突变cDNA进行了番茄感染性和症状诱导特性分析，并检测了其相应RNA的二级结构。感染性、计算机分析和化学图谱数据的综合结果表明，先前提出的热力学稳定性与PSTVd致病性之间的相关性并非在所有情况下都成立，并表明与宿主因子的构象和/或序列特异性相互作用在症状发展中起作用。
