Sohrab Sayed Sartaj
Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Post Box No: 80216, Jeddah 21589, Saudi Arabia.
Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Saudi Arabia.
Saudi J Biol Sci. 2020 Jan;27(1):222-228. doi: 10.1016/j.sjbs.2019.08.015. Epub 2019 Aug 22.
Tomato is known as a highly valuable crop and grown worldwide for various uses. The cultivation and tomato production severely affected globally by several diseases caused by various pathogens. Begomoviruses causes yellow mosaic and leaf curl disease of tomato in the tropical, subtropical, temperate, and semi-arid regions. In Saudi Arabia, the tomato production adversely affected by disease caused by begomoviruses known as TYLCV and ToLCSDV In this study, the pathogen was identified by Polymerase Chain Reaction using virus-specific primers and transmitted by whiteflies to healthy tomato seedlings. In a field survey, the tomato plants were exhibiting symptoms like viral infection. The infected leaf was randomly collected from various fields of tomato growing areas like Jeddah, Makkah, Tabuk, and Hail. The full-length viral genome was amplified by Rolling Circle Amplification technology (RCA) while betasatellites were amplified by PCR using universal betasatellites primers. The full-length viral genome (∼2.7 kb) and betasatellites (∼1.4 kb) were cloned and sequenced bi-directionally. The generated sequences were assembled and analyzed to find out the genetic variability by using bioinformatics tools and the genetic variability and phylogenetic relationships with selected begomoviruses were analyzed. The sequences showed the highest identity with an isolate of ToLCSDV and TYLCV. The nucleotide similarity and phylogenetic relationship showed the closest cluster with ToLCSDV and TYLCV. The data generated in this study elucidate that the causal organism is a variant of either TYLCV or ToLCSDV. The provided information from this study will be highly valuable for researchers and vegetable growers not only in Saudi Arabia but also in Arabian Peninsula.
番茄是一种极具价值的作物,在全球范围内广泛种植,用途多样。番茄的种植和生产受到多种病原体引发的多种病害的严重影响。双生病毒在热带、亚热带、温带和半干旱地区引发番茄的黄花叶和卷叶病。在沙特阿拉伯,番茄生产受到由双生病毒引起的病害的不利影响,这些病毒被称为番茄黄化曲叶病毒(TYLCV)和番茄叶卷曲苏丹病毒(ToLCSDV)。在本研究中,使用病毒特异性引物通过聚合酶链反应鉴定病原体,并通过粉虱传播给健康的番茄幼苗。在田间调查中,番茄植株表现出病毒感染的症状。从吉达、麦加、塔布克和海勒等番茄种植区的各个田地随机采集感染的叶片。通过滚环扩增技术(RCA)扩增全长病毒基因组,而使用通用卫星引物通过PCR扩增卫星DNA。将全长病毒基因组(约2.7 kb)和卫星DNA(约1.4 kb)进行克隆并双向测序。对生成的序列进行组装和分析,以使用生物信息学工具找出遗传变异性,并分析与选定双生病毒的遗传变异性和系统发育关系。这些序列与ToLCSDV和TYLCV的一个分离株具有最高的同一性。核苷酸相似性和系统发育关系显示与ToLCSDV和TYLCV的聚类最接近。本研究产生的数据表明,致病生物是TYLCV或ToLCSDV的一个变体。本研究提供的信息不仅对沙特阿拉伯的研究人员和蔬菜种植者,而且对阿拉伯半岛的研究人员和蔬菜种植者都将具有极高的价值。