Yıldırım Kubilay, Kavas Musa, Kaya Rıza, Seçgin Zafer, Can Cansu, Sevgen Ilkay, Saraç Çiğdem Gökçek, Tahan Vahid
Ondokuz Mayıs University, Dep.of Molecular Biology and Genetics, Samsun, Turkey.
Ondokuz Mayıs University, Dep.of Agricultural Biotechnology, Samsun, Turkey.
J Virol Methods. 2022 Feb;300:114380. doi: 10.1016/j.jviromet.2021.114380. Epub 2021 Nov 24.
Beet curly top disease (BCTD) is a yield-limiting viral infection of sugar beet (Beta vulgaris) throughout the arid and semi-arid regions of the world. Two virus species, belonging to two different genera of the family Geminiviridae (Curtovirus and Becurtovirus) had been described as the disease's causative agents on sugar beet. Despite the detection of the BCTD in some sugar beet fields of Turkey sixty years ago, the genome based characterization of BCTD-associated viruses have not been studied previously. In this study, 628 sugar beet plants exhibiting BCTD symptoms were collected from fourteen cities in central Anatolia, the major sugar beet production areas in Turkey. PCR assays of these samples using the respective Curtovirus and Becurtovirus genus-specific primers indicated that the Turkish sugar beet samples' viral sequences belong only to the genus Becurtovirus. The results of sequencing and phylogenetic analysis of the partial genome of the virus obtained from fourteen cities confirmed that BCTD-associated virus in Turkish sugar beet fields is beet curly top Iran virus (BCTIV-Becurtovirus) species. The whole genome of the collected viruses from fourteen cities were amplified by the rolling circle amplification (RCA) and the five most phylogenetically diverse viruses obtained from Afyon, Ankara, Adapazarı, Yozgat and Aksaray were sequenced. The results of whole genome sequence analysis indicated >98 % sequence identities with that of a BCTIV variants reported from Urmia province (bordering Turkey) of Iran. A virus genome from Yozgat city had a genomic sequence identity of >97 % with those of BCTIV isolated from cowpea, tomato, pepper and sugar beet in the northern part of Iran. These results suggested that the spread of BCTIV through the region could create a significant threat to the production of sugar beet as well as other agricultural crops. A tandem dimer of a BCTIV-Turkish variant isolated from Ankara city was cloned into Agrobacterium plasmid to be used for agro-infection studies. Agroinoculation of this construct on sugar beet leaves generated severe BCTD symptoms (84 %) which were also confirmed by RCA and qPCR analysis. These results constituted the first genome based characterization of BCTIV Turkish variants and the first report of BCTIV spreading out of Iran.
甜菜曲顶病（BCTD）是一种限制全球干旱和半干旱地区甜菜（Beta vulgaris）产量的病毒感染病害。两种病毒物种，属于双生病毒科（Geminiviridae）的两个不同属（曲顶病毒属和贝曲顶病毒属），已被描述为甜菜上该病害的病原体。尽管60年前在土耳其的一些甜菜田中检测到了BCTD，但此前尚未对与BCTD相关病毒进行基于基因组的特征研究。在本研究中，从土耳其主要甜菜产区安纳托利亚中部的14个城市收集了628株表现出BCTD症状的甜菜植株。使用各自的曲顶病毒属和贝曲顶病毒属特异性引物对这些样本进行PCR检测，结果表明土耳其甜菜样本的病毒序列仅属于贝曲顶病毒属。对从14个城市获得的病毒部分基因组进行测序和系统发育分析的结果证实，土耳其甜菜田中与BCTD相关的病毒是甜菜曲顶伊朗病毒（BCTIV - 贝曲顶病毒）物种。通过滚环扩增（RCA）扩增了从14个城市收集的病毒的全基因组，并对从阿菲永、安卡拉、阿达帕扎勒、约兹加特和阿克萨赖获得的5种系统发育差异最大的病毒进行了测序。全基因组序列分析结果表明，与从伊朗乌尔米亚省（与土耳其接壤）报道的一种BCTIV变体的序列同一性>98%。约兹加特市的一种病毒基因组与从伊朗北部豇豆、番茄、辣椒和甜菜中分离的BCTIV的序列同一性>97%。这些结果表明，BCTIV在该地区的传播可能对甜菜以及其他农作物的生产构成重大威胁。从安卡拉市分离的一种BCTIV - 土耳其变体的串联二聚体被克隆到农杆菌质粒中，用于农杆菌感染研究。将该构建体接种到甜菜叶片上产生了严重的BCTD症状（84%），RCA和qPCR分析也证实了这一点。这些结果构成了对BCTIV土耳其变体的首次基于基因组的特征描述，也是BCTIV传播出伊朗的首次报道。
