Tomato leaf curl virus from Bangalore (ToLCV-Ban4): sequence comparison with Indian ToLCV isolates, detection in plants and insects, and vector relationships
Tomato leaf curl virus from Bangalore (ToLCV-Ban4): sequence comparison with Indian ToLCV isolates, detection in plants and insects, and vector relationships
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DOI：
10.1007/s007050070078
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发表时间：
2000-01-01
影响因子：
2.7
通讯作者：
Czosnek, H
中科院分区：
文献类型：
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作者：
Muniyappa, V;Venkatesh, HM;Czosnek, H
番茄曲叶病毒（Tomato Leaf Curl Virus，ToLCV）是由烟粉虱（Bemisia tabaci）传播的双生病毒属（Geminiviridae，Begomovirus）的一种病毒，在印度、东亚和澳大利亚的许多地区引起番茄的毁灭性病害。虽然来自澳大利亚和台湾的ToLCV分离物具有单一基因组组分（称为DNA-A），但来自印度北方的ToLCV分离物具有两种组分（DNA-A和DNA-B）。先前克隆的来自印度南部（班加罗尔）的ToLCV分离株似乎具有DNA-A样单组分基因组。我们已经使用简并DNA-A特异性PCR引物克隆ToLCV分离物（命名为ToLCV-Ban 4）的基因组，该分离物来自1997年生长在印度班加罗尔的田间感染番茄植株。简并DNA-B特异性PCR引物不允许从感染的番茄中扩增推定的DNA-B，当DNA-B片段从已知的双分菜豆花叶病毒感染的植物中扩增时。对全长2759个核苷酸长的DNA-A样病毒基因组进行测序。与其他单分ToLCV和TYLCV分离株类似，ToLCV-Ban 4含有六个开放阅读框，两个在病毒体链上，四个在互补链上。序列比较表明，ToLCV-Ban 4与先前测序的来自班加罗尔的其他三个分离物相似，并且与ToLCV-Ban 2密切相关（约91%核苷酸序列同一性）。系统发育分析表明，来自班加罗尔的ToLCV分离株构成了一组与北方印度分离的病毒。通过ELISA、Southern印迹杂交和PCR中的一种或组合检测番茄及其烟粉虱载体中的ToLCV-Ban 4。在实验室中研究了粉虱媒介的病毒获得、保留和传播参数。单个粉虱能够从受感染的番茄获得ToLCV-Ban 4并将病毒传播到番茄测试植物，但需要5只昆虫才能实现100%的传播。最小采集访问和接种访问时间分别为10分钟和20分钟。B的潜伏期为6 h。烟粉虱有效感染番茄测试植物。在24小时的采集访问期后，昆虫保留其感染番茄测试植物的能力达12天，但不是在其整个生命周期内。在一种昆虫/一株植物接种试验中，雌性粉虱在传播病毒方面比雄性粉虱更有效（相似于95%）（相似于25%）。
Tomato leaf curl virus (ToLCV) is a whitefly (Bemisia tabaci) transmitted geminivirus (family Geminiviridae, genus Begomovirus) causing a destructive disease of tomato in many regions of India, East Asia and Australia. While ToLCV isolates from Australia and Taiwan have a single genomic component (designated DNA-A), those from Northern India have two components (DNA-A and DNA-B). The ToLCV isolates from Southern India (Bangalore) previously cloned seem to have a DNA-A-like monopartite genome. We have used degenerate DNA-A-specific PCR primers to clone the genome of a ToLCV isolate (named ToLCV-Ban4) from field-infected tomato plants growing in Bangalore, India, in 1997. Degenerate DNA-B-specific PCR primers have not allowed to amplify a putative DNA-B from infected tomato, at the time when DNA-B fragments were amplified from plants infected by known bipartite begomoviruses. The full-length 2759 nucleotide-long DNA-A-like viral genome was sequenced. Similarly to other monopartite ToLCV and TYLCV isolates, ToLCV-Ban4 contains six open reading frames, two on the virion strand and four on the complementary strand. Sequence comparisons indicated that ToLCV-Ban4 is similar to the other three isolates from Bangalore previously sequenced, and is closely related to ToLCV-Ban2 (approximately 91 % nucleotide sequence identity). Phylogenetic analysis showed that the ToLCV isolates from Bangalore constitute a group of viruses separated from those of Northern India. ToLCV-Ban4 was detected in tomato and in its whitefly vector Bemisia tabaci by one or by a combination of ELISA, Southern blot hybridization and PCR. Parameters of virus acquisition, retention and transmission by the whitefly vector were investigated in the laboratory. Single whiteflies were able to acquire ToLCV-Ban4 from infected tomato and to transmit the virus to tomato test plants, but five insects were necessary to achieve 100% transmission. Minimum acquisition access and inoculation access periods were 10 min and 20 min, respectively. A latent period of 6 h was required for B. tabaci to efficiently infect tomato test plants. Following a 24 h acquisition access period the insect retained its ability to infect tomato test plants for 12 days, but not for its entire life. In one insect/one plant inoculation tests, female whiteflies were more efficient (similar to 95%) than males (similar to 25%) in transmitting the virus.