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雙生病毒科
鎖定
- 中文學名
- 雙生病毒科
- 拉丁學名
- Geminiviridae
- 界
- 病毒界
- 科
- 雙生病毒科
雙生病毒科特徵
病毒粒子為雙聯體結構，每個粒子大小為18nm×30nm，無包膜，由兩個不完整的二十面體組成（T=1），共有22個五聚體殼粒。病毒的外殼蛋白由單個多肽組成，分子質量為28~34kDa，每個殼粒結構估計有5個外殼蛋白分子。
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該科是植物病毒中惟一具有單鏈DNA的單分體或二分體基因組病毒。病毒包裹單分子或兩分子閉環狀ssDNA，每分子DNA長2.5~3.0kb，總基因長約2.5~5.2kb。編碼區分佈於DNA的病毒鏈和互補鏈，其中間為基因間隔區。病毒複製是經一個雙鏈複製中間體，通過滾環複製，ssDNA合成起始於基因間隔區的一段保守序列TAATATT/AC，病毒基因雙向轉錄，在基因間隔區具有轉錄起始點。大多數雙生病毒的增殖部位侷限於植物韌皮部組織，在細胞核中形成病毒粒子聚集體，細胞核膨大並形成顆粒狀結構和纖維狀結構，纖維狀環可能是病毒複製裝配的場所。
[1]
雙生病毒科分佈
雙生病毒科的病毒一般發生在熱帶和亞熱帶地區。該科中的玉米線條病毒屬主要限於侵染禾本科單子葉植物，菜豆金色花葉病毒屬和曲頂病毒屬侵染雙子葉植物。自然界中，玉米線條病毒屬和曲頂病毒屬通過葉蟬以持久方式傳播，菜豆金色花葉病毒屬通過粉蝨以持久方式傳播，病毒在介體昆蟲中不繁殖，蟲卵不帶毒。有些種也可以通過機械傳毒，但通常較難。病毒具有效的免疫原性，菜豆金色花葉病毒屬內病毒之間有血清學關係，曲頂病毒屬與菜豆金色花葉病毒屬的一些病毒有遠緣血清學關係。
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雙生病毒科分類
雙生病毒科的系統發育樹
transmitted by leafhoppers to dicotyledonous plants
· Genus Begomovirus; type species: Bean golden mosaic virus;
transmitted by whiteflies (Bemisia spp.) to dicotyledonous
plants:
· Genus Curtovirus; type species: Beet curly top virus; transmitted
by leafhoppers or treehoppers to dicotyledonous plants
· Genus Eragrovirus; type species: Eragrostis curvula streak
virus; infects monocotyledonous plants
· Genus Mastrevirus; type species: Maize streak virus; transmitted
by leafhoppers, usually to monocotyledonous plants
· Genus Topocuvirus; type species: Tomato pseudo-curly top
virus; transmitted by treehoppers to dicotyledonous plants
· Genus Turncurtovirus; type species: Turnip curly top virus;
infects dicotyledonous plants.
- 參考資料
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- 1. 洪健，李德葆，周雪平主編。2001.12。植物病毒分類圖譜。北京:科學出版社
- 2. Tomato Yellow Leaf Curl Virus: A Serious Threat to Tomato Plants World Wide J Basak - 2016 - 被引量: 0 Tomato (Solanum lycopersicum) is one of the widely grown crops worldwide. It is consumed in various forms and has excellent nutritional values. Presently, this crop is facing a serious threat to its yield and survival because of Geminivirus infection. One of the Geminivirus species hampering tomato productions world-wide is Tomato yellow leaf curl virus (TYLCV). Tomato yellow leaf curl disease is one of the most destructive plant diseases destroying the tomato crops globally. It has spread to many countries worldwide including Southern, Central and Northern parts of America, Southern Asia, Africa and Mediterranean basin. TYLCV genome consists of a circular single stranded DNA of 2.7 kb in size and occasionally contains beta satellite of 1.3 kb. TYLCV genome encodes six open reading frames, of which two are in the viral orientation and four are in the complementary orientation. TYLCV is transmitted by the insect vector Bemisia tabaci, commonly known as the silverleaf white fly. This review provides an overview of Geminiviruses with special emphasis on TYLCV, virus vector relationship between TYLCV and white fly, different strains of TYLCV, its genome organization and replication, present status of its spread in different parts of the world and strategies employed for controlling it. The knowledge about the recent progress in the study of TYLCV would help develop novel strategies for its control in agriculture.
