First Report of Sweet potato leaf curl Georgia virus on Sweet Potato in China

Begomoviruses infecting sweet potato (Ipomoea batatas) are phylogenetically distinct from other members of the genus Begomovirus, and have been named “sweepoviruses” (1). Sweepoviruses cause sweet potato yield losses and cultivar decline, and have been found in China (1,3). In 2011, a survey was conducted to determine the incidence, genetic diversity, and distribution of sweepoviruses in China. Thirty sweet potato cuttings showing upward leaf curl, leaf roll, chlorosis, and stunting were collected from fields in Jiangsu, Guangxi, Guizhou, Shanxi, Henan, and Hebei Provinces. Five-leaf growth stage I. setosa plants were inoculated by side-grafting with scions from these samples, and grown in an insect-proof greenhouse in 20-cm-diameter clay pots. Each sample was grafted onto three replicate plants. Healthy, non-grafted I. setosa plants were used as the negative control treatment. Total nucleic acids were extracted from 100 mg fresh leaves harvested 30 days post-inoculation (dpi) from symptomatic and negative control plants using the Universal Genomic DNA Extraction Kit (TaKaRa, Dalian, China). Universal primers for amplification of Geminiviruses (BM-V [5′-KSGGGTCGACGTCATCAATGACGTTRTAC-3′] and BM-C [5′-AARGAATTCATKGGGGCCCARARRGACTGGC-3′]) (2) were used to amplify the begomovirus A component by PCR assay. A DNA fragment of the expected size (2.8 kb) was obtained from grafted leaf samples of the Hebei Province plant, and was cloned into the pMD-19T vector (TaKaRa). The recombinant plasmid was transformed into competent cells of Escherichia coli strain JM109, and the inserted fragment sequenced. The nucleotide sequence obtained (GenBank Accession No. JX448368) was 2,785 nt long, and contained two open reading frames (ORFs) in the virion sense, and four ORFs in the complementary sense, similar to other monopartite begomoviruses (1). The sequence was compared with sequences in GenBank using BLAST. The results revealed the greatest nucleotide sequence identity, 90.8%, with that of the Sweet potato leaf curl Georgia virus (SPLCGV) from Georgia, United States (AF326775). The sequence also shared identities of <89% with other sweepoviruses, and was therefore designated SPLCGV-China: Hebei: 2011. Comparison of the complete genome sequence of SPLCGV-China: Hebei: 2011 with SPLCGV revealed an 18 nucleotide insertion between AV-1 and AC-3. The results confirmed that the sweet potato sample from which SPLCGV-China: Hebei: 2011 was obtained was infected with SPLCGV. To our knowledge, this is the first report of the natural occurrence of SPLCGV in China. This study will assist with understanding the presence of this virus and genetic diversity of sweepoviruses in China. References: (1) H. P. Bi and P. Zhang. Arch. Virol. 157:441, 2012. (2) R. W. Briddon and P. G. Markham. Mol. Biotechnol. 1:202, 1994. (3) Y. S. Luan et al. Virus Genes 35:379, 2007.

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First Report of the Occurrence of Sweet potato leaf curl virus in Tall Morningglory (Ipomoea purpurea) in China

Plant Disease ◽

10.1094/pdis-93-7-0764b ◽

2009 ◽

Vol 93 (7) ◽

pp. 764-764 ◽

Cited By ~ 9

Author(s):

C. X. Yang ◽

Z. J. Wu ◽

L. H. Xie

Keyword(s):

Sweet Potato ◽

Dna Sequences ◽

Ipomoea Batatas ◽

Rolling Circle Amplification ◽

The United States ◽

Natural Occurrence ◽

Potato Leaf ◽

First Report ◽

Leaf Curl Virus ◽

Leaf Curl

Natural occurrence of Sweet potato leaf curl virus (SPLCV) has been reported in Ipomoea batatas (sweet potato, Convolvulaceae) or I. indica (Convolvulaceae) in several countries including the United States, Sicily, and China (1–3). In September of 2007, while collecting samples showing begomovirus-like symptoms in the Chinese province of Fujian, we observed tall morningglory (I. purpurea (L.) Roth, also known as Pharbitis purpurea (L.) Voigt), plants with slightly yellow mosaic and crinkled leaves. Total DNA was extracted from leaves of these plants and tested by rolling circle amplification (4). Amplification products were digested by the restriction enzyme BamHI for 30 min. Restriction products (2.8 kb) were then cloned into pMD18T vector (Takara Biotechnology, China) and sequenced. Comparison of complete DNA sequences by Clustal V analysis revealed that these samples were infected by the same virus, and an isolate denoted F-p1 was selected for further sequence analysis. F-p1 was 2,828 nucleotides, with the typical genomic organization of begomoviral DNA-A (GenBank Accession No. FJ515896). F-p1 was compared with the DNA sequences available in the NCBI database using BLAST. The whole DNA sequence showed the highest nucleotide sequence identity (92.1%) with an isolate of SPLCV (GenBank Accession No. FJ176701) from Jiangsu Province of China. The result confirmed that the samples from the symptomatic tall morningglory were infected by SPLCV. To our knowledge, this is the first report of the natural occurrence of SPLCV in I. purpurea, a common weed species in China. References: (1). P. Lotrakul et al. Plant Dis. 82:1253, 1998. (2). R. W. Briddon et al. Plant Pathol. 55:286, 2006. (3) Y. S. Luan et al. Virus Genes 35:379, 2007. (4) D. Haible et al. J. Virol. Methods 135:9, 2006.

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First Report of Sweet potato leaf curl virus in China

Plant Disease ◽

10.1094/pd-90-1111c ◽

2006 ◽

Vol 90 (8) ◽

pp. 1111-1111 ◽

Cited By ~ 20

Author(s):

Y. S. Luan ◽

J. Zhang ◽

L. J. An

Keyword(s):

Sweet Potato ◽

Large Population ◽

The United States ◽

Universal Primers ◽

Natural Occurrence ◽

Potato Leaf ◽

First Report ◽

Bipartite Genome ◽

Leaf Curl Virus ◽

Leaf Curl

During the 2004 growing season in the Liaoning Province in China, where there was large population of whiteflies, several sweet potato (Ipomoea batatas) breeding lines showed leaf curl symptoms. A survey was conducted to determine the incidence of Sweet potato leaf curl virus (SPLCV) in China. Sixteen plants were collected and stem scions from those plants were graft inoculated to Ipomoea nil. Three weeks later, the indicator developed symptoms of leaf curling, interveinal chlorosis, and stunting. Total nucleic acid was extracted from young leaves of sweet potato and then evaluated using polymerase chain reaction (PCR). Primers, developed by Briddon and Markham (1) and used as universal primers for amplification of the geminivirus DNA fragment, were BM-V (5′-KSG GGT CGA CGT CAT CAA TGA CGT TRT AC-3′) and BM-C (5′-AAR GAA TTC ATK GGG GCC CAR ARR GAC TGG C-3′). Amplified fragments with BM primers theoretically should have sizes almost equal to the full length of the DNA A component of the bipartite genome (2). Expected DNA fragments of 2.8 kb that contained the AV1, AV2, AC1, AC2, AC3, and AC4 open reading frames were obtained from symptomatic, but not from symptomless (uninfected) plants. The 2.8-kb fragments obtained by amplification were purified and cloned into the PMD18-T vector. Recombinant plasmids were then transformed into competent cells of Escherichia coli strain DH5(. The fragment was sequenced (GenBank Accession No. DQ512731), and nucleotide sequence of corresponding regions were compared with a published sequence of SPLCV available in GenBank (Accession No. AF104036). The AC4 and AC2 genes showed the highest (92%) and the lowest (83%) identity, respectively. This virus has been reported in the United States, Taiwan, Japan, and Peru. To our knowledge, this is the first report of the natural occurrence of SPLCV in China. References: (1) R. W. Briddon and P. G. Markham. Mol. Biotechnol. 1:202, 1994. (2) M. Onuki and K. Hanada. Ann. Phytopathol. Soc. Jpn. 64:116, 1998.

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First Report of Sweet potato leaf curl virus Infecting Sweet Potato in Sudan

Plant Disease ◽

10.1094/pdis-12-16-1705-pdn ◽

2017 ◽

Vol 101 (5) ◽

pp. 849 ◽

Cited By ~ 3

Author(s):

H. S. Mohammed ◽

M. A. El Siddig ◽

A. A. El Hussein ◽

F. A. Ibrahim ◽

J. Navas-Castillo ◽

...

Keyword(s):

Sweet Potato ◽

Potato Leaf ◽

First Report ◽

Leaf Curl Virus ◽

Leaf Curl

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First Report of Sweet potato leaf curl virus and Sweet potato leaf curl deltasatellite 1 Infecting Blue Morning Glory in Portugal

Plant Disease ◽

10.1094/pdis-10-17-1667-pdn ◽

2018 ◽

Vol 102 (5) ◽

pp. 1043

Author(s):

E. Fiallo-Olivé ◽

D. Lapeira ◽

D. Louro ◽

J. Navas-Castillo

Keyword(s):

Sweet Potato ◽

Morning Glory ◽

Potato Leaf ◽

First Report ◽

Leaf Curl Virus ◽

Leaf Curl

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First Report of a Begomovirus Infecting Sweetpotato in Kenya

Plant Disease ◽

10.1094/pd-90-0832b ◽

2006 ◽

Vol 90 (6) ◽

pp. 832-832 ◽

Cited By ~ 27

Author(s):

D. W. Miano ◽

D. R. LaBonte ◽

C. A. Clark ◽

R. A. Valverde ◽

M. W. Hoy ◽

...

Keyword(s):

Sweet Potato ◽

Germplasm Collection ◽

Degenerate Primers ◽

Potato Leaf ◽

First Report ◽

Two Samples ◽

Total Dna ◽

Dna Fragment ◽

Pcr Assays ◽

Leaf Curl

Previous surveys for viruses in sweetpotatoes (Ipomoea batatas) in Africa did not assay for the presence of begomoviruses such as Sweet potato leaf curl virus (SPLCV), which have been found recently in the Americas and Asia. Symptomatic sweetpotato plants, including some with leaf curling symptoms similar to those observed in SPLCV-infected sweet-potato plants (2), were collected from a germplasm collection plot at Kakamega Research Station in Western Kenya during February 2005. Whiteflies, the vectors for begomoviruses, were observed in the same plots. Ipomoea setosa plants graft-inoculated with scions from the symptomatic sweetpotato developed leaf curl, leaf roll, interveinal chlorosis, and stunting symptoms similar to those caused by infection with SPLCV alone or in combination with Sweet potato feathery mottle virus. Total DNA was isolated from 10 I. setosa plants using the GenElute Plant Genomic DNA Kit (Sigma-Aldrich Inc., St. Louis, MO). Sweetpotato cuttings from 39 clones, selected from the Kenyan germplasm collection for their resistance or susceptibility to sweetpotato virus disease (SPVD), were sent to the Plant Germplasm Quarantine Office of USDA-ARS. The cuttings were planted in a greenhouse. Total DNA was extracted from sweetpotato leaves 1 month later using a cetyltrimethylammoniumbromide (CTAB) extraction method (1). Degenerate primers SPG1/SPG2, developed for PCR detection of begomoviruses (1), amplified a 912-bp DNA fragment from 3 of 10 DNA extracts from I. setosa and 5 of 39 sweetpotato plants held in quarantine. The primers anneal to regions of open reading frame (ORF) AC2 and ORF AC1 that are highly conserved in begomoviruses infecting sweetpotato. SPLCV-specific primers PW285-1/PW285-2 (2) amplified a 512-bp DNA fragment of ORF AC1 from seven samples (two from I. setosa and five from I. batatas). Amplicons from three independent PCR assays of two samples and single PCR assays of four additional samples were cloned into the pGEM-T Easy vector. Clone inserts were sequenced, and compared with sequences deposited in GenBank using the basic local alignment search tool (BLAST). Sequences were closely related to SPLCV (GenBank Accession No. AF104036) with nucleotide sequence identities varying from 93% (GenBank Accession No. DQ361004) to 97% (GenBank Accession No. DQ361005). The presence of the virus poses a challenge to the dissemination of planting materials in the region because begomovirus-infected plants often do not show symptoms. To our knowledge, this is the first report of a begomovirus infecting sweetpotato in Kenya or the East African Region. References: (1) R. Li et al. Plant Dis. 88:1347, 2004. (2) P. Lotrakul et al. Plant Dis. 82:1253, 1998.

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First Report of Sweet potato leaf curl virus on Blue Morning Glory in Greece

Plant Disease ◽

10.1094/pdis-09-13-0986-pdn ◽

2014 ◽

Vol 98 (5) ◽

pp. 700-700 ◽

Cited By ~ 4

Author(s):

E. Fiallo-Olivé ◽

N. I. Katis ◽

J. Navas-Castillo

Keyword(s):

Sweet Potato ◽

Rolling Circle Amplification ◽

Morning Glory ◽

Yellow Vein ◽

Nucleotide Identity ◽

Potato Leaf ◽

First Report ◽

Crete Island ◽

Leaf Curl Virus ◽

Leaf Curl

Blue morning glory (Ipomoea indica, Convolvulaceae) plants are widespread along the Greek coast, where they grow as weeds in addition to being cultivated as ornamentals. Yellow vein symptoms are frequently observed on these plants. These symptoms are similar to those reported for isolates of Sweet potato leaf curl virus (SPLCV) infecting I. indica in Italy and Spain (1,3). SPLCV belongs to the sweepoviruses, a unique group within the genus Begomovirus in the family Geniminiviridae that infects sweet potato (I. batatas) crops around the world. In May 2013, three leaf samples of I. indica showing yellow vein symptoms were collected in Kolymbari (Crete Island), where ~50% of the observed plants were symptomatic, and five asymptomatic leaf samples were collected in Kremasti and Mandriko (Rhodes Island). Total DNA, isolated from all samples, was used as a template in rolling-circle amplification (RCA) using ϕ29 DNA polymerase (TempliPhi kit, GE Healthcare, Little Chalfont, UK) and the product was digested with a set of restriction endonucleases. The samples from Kolymbari and one sample from Kremasti yielded amplification products that were shown to contain a single BamHI site. The DNA fragments of ~2.8 kbp obtained from one sample from each island were cloned into pBluescript II SK(+) (Stratagene, La Jolla, CA). Inserts of two clones from the Kolymbari sample and one clone from the Kremasti sample were completely sequenced (Macrogen, Seoul, South Korea). Sequences were aligned with available sequences of sweepoviruses using MUSCLE and pairwise identity scores were calculated with SDT as described (4). The sequences obtained from Kolymbari (2,830 nt, GenBank Accession Nos. KF697069 and KF697070) were 98.8% similar between them and showed the highest nucleotide identity (97.7%) with a SPLCV isolate obtained from an I. indica plant in Sicily Island (Italy) (AJ586885) (1). The sequence obtained from Kremasti (2,804 nt, KF697071) showed the highest nucleotide identity (92.4%) with a SPLCV isolate (previously named as Ipomoea yellow vein virus, which is currently a synonym of SPLCV [2]) obtained from an I. indica plant from southern Spain (EU839578) (3). Nucleotide sequence identities were above the 91% threshold for begomovirus species demarcation (2), thus confirming that the begomoviruses found infecting I. indica in Greece are isolates of SPLCV. It is worth to note that the infected I. indica plant from Kremasti did not show any conspicuous symptoms, thus highlighting the importance of this species as an alternative host for SPLCV, which could thus affect the sweet potato crop that is grown in Greece in familiar plots. To our knowledge, this is the first report of SPLCV in Greece. References: (1) R. W. Briddon et al. Plant Pathol. 55:286, 2006. (2) ICTV Geminiviridae Study Group. New species and revised taxonomy proposal for the genus Begomovirus (Geminiviridae). ICTV. Retrieved from http://talk.ictvonline.org/files/proposals/taxonomy_proposals_plant1/ m/plant04/4720.aspx , 20 November 2013. (3) G. Lozano et al. J. Gen. Virol. 90:2550, 2009. (4) B. Muhire et al. Arch. Virol. 158:1411, 2013.

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First Report of Sweet potato leaf curl Georgia virus Infecting Tall Morning Glory (Ipomoea purpurea) in China

Plant Disease ◽

10.1094/pdis-11-13-1161-pdn ◽

2014 ◽

Vol 98 (11) ◽

pp. 1588-1588

Author(s):

S. B. Zhang ◽

Z. G. Du ◽

Z. Wang ◽

Y. F. Tang ◽

X. M. She ◽

...

Keyword(s):

Sweet Potato ◽

Rolling Circle Amplification ◽

The United States ◽

Morning Glory ◽

Central China ◽

Potato Leaf ◽

First Report ◽

Ipomoea Purpurea ◽

Sequence Identity ◽

Leaf Curl

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.

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