Zhang Song, Yang Liu, Ma Lisha, Tian Xin, Li Ruhui, Zhou Changyong, Cao Mengji
National Citrus Engineering and Technology Research Center, Citrus Research Institute, Southwest University, Chongqing, China.
State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing, China.
Front Microbiol. 2020 May 15;11:945. doi: 10.3389/fmicb.2020.00945. eCollection 2020.
Many species of the genus are native to China, and several species such as have been cultivated as garden plants for over 1,000 years. Virus-like symptoms have been recorded for years. In this study, plants with various leaf symptoms were observed in Jiangxi and Chongqing provinces. The species composition of potential viruses in the symptomatic plants was analyzed by next-generation sequencing of six libraries prepared from total RNAs of specimens from 10 trees. Five new viruses were discovered, and their genome sequences were determined. These viruses were tentatively named Camellia chlorotic ringspot viruses (CaCRSVs), Camellia yellow ringspot virus (CaYRSV), Camellia-associated badnavirus (CaBaV), and Camellia-associated marafivirus (CaMaV) based on comprehensive analyses. Among these viruses, CaYRSV, CaBaV, and CaMaV share similar genome organizations and clear sequence homology with known viruses in databases and could potentially be classified as new species of the genera , and , respectively. CaCRSVs comprise two distinct viruses, and each likely contains five genomic RNA segments that were found to be distantly related to viral RNAs of members in the genus (family ). The RNAs of CaCRSVs show conserved terminal sequences that differ markedly from those of emaraviral RNAs. These data, together with the phylogenetic analysis, suggest that the evolutionary status of CaCRSVs may represent a novel genus in the family . In addition, two known viruses (geminivirus and blunervirus) and a mass of betaflexiviruses existing as heterogeneous mixtures were detected, and their roles in symptom formation were studied. Collectively, the information of the viral species and detection protocols that were developed can serve as a basis for better management of these viruses. Distinguishing the virus-related symptoms from genetic characteristics of is also significant for breeding efforts.
该属的许多物种原产于中国，诸如[具体物种名称未给出]等几个物种作为园林植物已被栽培了1000多年。多年来一直有类似病毒的症状记录。在本研究中，在江西和重庆两省观察到了具有各种叶片症状的[植物名称未给出]植株。通过对从10棵树的标本总RNA制备的6个文库进行二代测序，分析了有症状植株中潜在病毒的物种组成。发现了5种新病毒，并确定了它们的基因组序列。基于综合分析，这些病毒被暂定为山茶褪绿环斑病毒（CaCRSVs）、山茶黄环斑病毒（CaYRSV）、山茶相关杆状DNA病毒（CaBaV）和山茶相关马拉病毒（CaMaV）。在这些病毒中，CaYRSV、CaBaV和CaMaV具有相似的基因组结构，并且与数据库中的已知病毒具有明显的序列同源性，可能分别被归类为[相应属名未给出]、[相应属名未给出]和[相应属名未给出]的新物种。CaCRSVs由两种不同的病毒组成，每种可能包含5个基因组RNA片段，发现它们与[科名未给出]科[属名未给出]属成员的病毒RNA关系较远。CaCRSVs的RNA显示出保守的末端序列，与埃玛拉病毒RNA的末端序列明显不同。这些数据以及系统发育分析表明，CaCRSVs的进化地位可能代表[科名未给出]科中的一个新属。此外，还检测到两种已知病毒（双生病毒和[病毒名称未给出]病毒）以及大量以异质混合物形式存在的β-柔曲病毒，并研究了它们在症状形成中的作用。总体而言，所开发的病毒物种信息和检测方案可为更好地管理这些病毒提供依据。区分与病毒相关的症状和[植物名称未给出]的遗传特征对于育种工作也具有重要意义。
