State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310029, People's Republic of China.
Appl Environ Microbiol. 2011 May;77(9):3092-101. doi: 10.1128/AEM.00017-11. Epub 2011 Mar 4.
A novel tomato-infecting begomovirus from Guangxi province, China, was identified and characterized, for which the name Tomato leaf curl China virus (ToLCCNV) was proposed. Phylogenetic and recombination analyses of the virus genomic sequences suggested that ToLCCNV may have arisen by recombination among Tomato leaf curl Vietnam virus (ToLCVV), Tomato leaf curl Gujarat virus (ToLCGV), and an unknown virus. A betasatellite molecule was found to be associated with ToLCCNV (ToLCCNB), and its complete nucleotide sequences were determined. Infectious clones of ToLCCNV and ToLCCNB were constructed and then used for agro-inoculation of plants; ToLCCNV alone infected Nicotiana benthamiana, Nicotiana glutinosa, Petunia hybrida, and Solanum lycopersicum plants, but no symptoms were induced. ToLCCNB was required for induction of leaf curl disease in these hosts. The βC1 protein of ToLCCNB was identified as a suppressor of RNA silencing and accumulated primarily in the nucleus. Deletion mutagenesis of βC1 showed that the central part of βC1 (amino acids 44 to 74) was responsible for both the suppressor activity and nuclear localization.
一种从中国广西分离得到的侵染番茄的新的单分体基因组双生病毒，暂命名为番茄曲叶中国病毒（Tomato leaf curl China virus，ToLCCNV）。病毒全基因组序列分析和系统进化分析表明，ToLCCNV 可能是由番茄曲叶病毒（Tomato leaf curl Vietnam virus，ToLCVV）、番茄曲叶古尔邦病毒（Tomato leaf curl Gujarat virus，ToLCGV）和一个未知的病毒重组产生的。该病毒伴随一个 betasatellite 分子（ToLCCNB），其全序列也已测定。ToLCCNV 和 ToLCCNB 的侵染性克隆已构建，并被用于植株的活体接种实验；ToLCCNV 单独侵染本氏烟、普通烟、矮牵牛和番茄，植株不表现症状；ToLCCNB 是诱导这些寄主植物产生曲叶症状所必需的。ToLCCNB 的 βC1 蛋白被鉴定为 RNA 沉默的抑制子，主要定位于细胞核。βC1 缺失突变体分析显示，βC1 的中心区域（氨基酸 44 到 74）同时负责抑制子活性和核定位。
