Zhang S B, Du Z G, Wang Z, Tang Y F, She X M, Lan G B, He Z F
College of Agriculture, Yangtze University, Jingzhou, Hubei, 434025, China.
Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou 510640, China.
Plant Dis. 2014 Nov;98(11):1588. doi: 10.1094/PDIS-11-13-1161-PDN.
In September 2013, tall morning glory (Ipomoea purpurea) plants showing vein yellowing and leaf curl symptoms typical of a begomovirus infection were observed in Jingzhou, Hubei Province, China. Total nucleic acids were extracted from a symptomatic plant using cetyltrimethylammonium bromide (CTAB). Rolling circle amplification (RCA) was conducted using TempliPhi kit (GE Healthcare) to recover the genome of a putative begomovirus. Digestion of the RCA product with PstI yielded a ~2.8 kbp DNA fragment suggestive of a monomerized begomoviral genome. The fragment was cloned and sequenced and the sequence was deposited in GenBank under accession no. KF769447. SDTv1.0 (species demarcation tool) analysis revealed that the putative begomovirus showed 98.5 and 92.0% nucleotide sequence identity with Sweet potato leaf curl Georgia virus (SPLCGV)-[China:Hebei:2011] (GenBank Accession No. JX448368) and SPLCGV-[US:Geo:16] (AF326775), respectively. The virus contained six ORFs, which encoded proteins showing 96.5 to 100% and 90.6 to 95.6% amino acid sequence identity with their counterparts of SPLCGV-[China:Hebei:2011] and SPLCGV-[US:Geo:16], respectively. Thus, the virus should be considered as an isolate of SPLCGV-[China:Hebei:2011]. Tall glory morning in a nearby field (which covers an area of 3 square kilometers) was surveyed and 70 to 100% of plants were found showing symptoms reminiscent of begomoviral infection. Total nucleic acid was extracted from 13 randomly selected (10 symptomatic and 3 healthy) plants and used as templates for PCR with a pair of specific primers (5'-CGCAGCCTTTCCACACTATC-3'/5'-AAAACAGTTTGGGCTCGGTC-3') designed according to the sequence described above. Positive results were obtained for all of the symptomatic, but none of the healthy-looking tall morning glory plants. SPLCGV (genus Begomovirus, family Geminiviridae) was reported to infect sweet potato (I. batatas) in the United States (4), India (2), and China (3). To our knowledge, this is the first report of SPLCGV infecting tall morning glory in China. Also, it is the first report of a geminivirus in Hubei, a province of central China. Whereas the finding of SPLCGV in sweet potato (3) may be a result of vegetative propagation of this crop, the detection of SPLCGV in tall morning glory, an annual plant, raises the possibility that this virus is transmissible and is spreading in China. References: (1) B. Muhire et al. Arch. Virol. 158:1411, 2013. (2) G. Prasanth and V. Hegde. Plant Dis. 92:311, 2008. (3) Y. Qin et al. Plant Dis. 97:1388, 2013. (4) R. A. Valverde and D. L. Gutierrez. Rev. Mex. Fitopatol. 21:128, 2003.
2013年9月，在中国湖北省荆州市观察到一些高大的牵牛（裂叶牵牛）植株，它们表现出典型的双生病毒感染症状，叶脉发黄且叶片卷曲。使用十六烷基三甲基溴化铵（CTAB）从一株有症状的植株中提取总核酸。使用TempliPhi试剂盒（通用电气医疗集团）进行滚环扩增（RCA），以恢复一种假定双生病毒的基因组。用PstI消化RCA产物产生了一个约2.8 kbp的DNA片段，提示为单体化的双生病毒基因组。该片段被克隆并测序，序列已提交至GenBank，登录号为KF769447。SDTv1.0（物种划分工具）分析显示，这种假定的双生病毒与甘薯卷叶佐治亚病毒（SPLCGV）-[中国：河北：2011]（GenBank登录号JX448368）和SPLCGV-[美国：佐治亚：16]（AF326775）的核苷酸序列同一性分别为98.5%和92.0%。该病毒含有六个开放阅读框（ORF），其编码的蛋白质与SPLCGV-[中国：河北：2011]和SPLCGV-[美国：佐治亚：16]相应蛋白质的氨基酸序列同一性分别为96.5%至100%和90.6%至95.6%。因此，该病毒应被视为SPLCGV-[中国：河北：2011]的一个分离株。对附近一块面积为3平方公里的田地里的高大牵牛进行了调查，发现70%至100%的植株表现出类似双生病毒感染的症状。从13株随机选取的植株（10株有症状的和3株健康的）中提取总核酸，并用作模板，使用根据上述序列设计的一对特异性引物（5'-CGCAGCCTTTCCACACTATC-3'/5'-AAAACAGTTTGGGCTCGGTC-3'）进行PCR。所有有症状的高大牵牛植株均得到阳性结果，而所有看似健康的植株均为阴性。据报道，双生病毒属的甘薯卷叶佐治亚病毒（SPLCGV）在美国（4）、印度（2）和中国（3）感染甘薯（甘薯）。据我们所知，这是SPLCGV在中国感染高大牵牛的首次报道。此外，这也是在中国中部省份湖北首次报道双生病毒。虽然在甘薯中发现SPLCGV（3）可能是该作物营养繁殖的结果，但在一年生植物高大牵牛中检测到SPLCGV增加了这种病毒具有传染性且正在中国传播的可能性。参考文献：（1）B. Muhire等人，《病毒学档案》158:1411，2013年。（2）G. Prasanth和V. Hegde，《植物病害》92:311，2008年。（3）Y. Qin等人，《植物病害》97:1388，2013年。（4）R. A. Valverde和D. L. Gutierrez，《墨西哥植物病理学杂志》21:128，2003年。
