| synergistic interactions of a potyvirus and a phloem-limited crinivirus in sweet potato plants. | when infecting alone, sweet potato feathery mottle virus (spfmv, genus potyvirus) and sweet potato chlorotic stunt virus (spcsv, genus crinivirus) cause no or only mild symptoms (slight stunting and purpling), respectively, in the sweet potato (ipomoea batatas l. ). in the spfmv-resistant cv. tanzania, spfmv is also present at extremely low titers, though plants are systemically infected. however, infection with both viruses results in the development of sweet potato virus disease (spvd) charact ... | 2000 | 10725195 |
| complete genome sequence and analyses of the subgenomic rnas of sweet potato chlorotic stunt virus reveal several new features for the genus crinivirus. | the complete nucleotide sequences of genomic rna1 (9,407 nucleotides [nt]) and rna2 (8,223 nt) of sweet potato chlorotic stunt virus (spcsv; genus crinivirus, family closteroviridae) were determined, revealing that spcsv possesses the second largest identified positive-strand single-stranded rna genome among plant viruses after citrus tristeza virus. rna1 contains two overlapping open reading frames (orfs) that encode the replication module, consisting of the putative papain-like cysteine protei ... | 2002 | 12186910 |
| further variability within the genus crinivirus, as revealed by determination of the complete rna genome sequence of cucurbit yellow stunting disorder virus. | the complete nucleotide (nt) sequences of genomic rnas 1 and 2 of cucurbit yellow stunting disorder virus (cysdv) were determined for the spanish isolate cysdv-allm. rna1 is 9123 nt long and contains at least five open reading frames (orfs). computer-assisted analyses identified papain-like protease, methyltransferase, rna helicase and rna-dependent rna polymerase domains in the first two orfs of rna1. this is the first study on the sequences of rna1 from cysdv. rna2 is 7976 nt long and contains ... | 2003 | 12917477 |
| some molecular characteristics of three viruses from spvd-affected sweet potato plants in egypt. | sweet potato feathery mottle virus (spfmv, genus potyvirus, family potyviridae), sweet potato chlorotic stunt virus (spcsv, genus crinivirus, family closteroviridae) and sweet potato virus g (spvg) were detected in naturally infected sweet potato plants grown in the delta region in egypt. before this study, spvg was reported only from china. two isolates of spfmv and one isolate of spvg were characterized for the 3'-proximal genomic sequences. phylogenetic analyses indicated that the spfmv isola ... | 2003 | 14648298 |
| control strategies for sweet potato virus disease in africa. | sweet potato virus disease (spvd), caused by dual infection with the whitefly-borne sweet potato chlorotic stunt virus (spcsv) and the aphid-borne sweet potato feathery mottle virus (spfmv), is the most serious disease of sweet potato in africa. spvd has been known there since at least the 1940s, although it took several decades to elucidate its aetiology. it occurs throughout africa and is particularly prevalent in the great lakes region. production of sweet potato is largely by resource-poor f ... | 2004 | 15036842 |
| whitefly transmission of sweet potato viruses. | three genera of plant viruses, begomovirus (geminiviridae), crinivirus (closteroviridae) and ipomovirus (potyviridae), contain members that infect sweet potato (ipomoea batatas) and are transmitted by whiteflies. the begomoviruses, sweet potato leaf curl virus (splcv) and ipomoea leaf curl virus (ilcv), and the ipomovirus sweet potato mild mottle virus are transmitted by bemisia tabaci, the sweet potato whitefly. the crinivirus, sweet potato chlorotic stunt virus (spcsv), is transmitted by b. ta ... | 2004 | 15036843 |
| viral class 1 rnase iii involved in suppression of rna silencing. | double-stranded rna (dsrna)-specific endonucleases belonging to rnase iii classes 3 and 2 process dsrna precursors to small interfering rna (sirna) or microrna, respectively, thereby initiating and amplifying rna silencing-based antiviral defense and gene regulation in eukaryotic cells. however, we now provide evidence that a class 1 rnase iii is involved in suppression of rna silencing. the single-stranded rna genome of sweet potato chlorotic stunt virus (spcsv) encodes an rnase iii (rnase3) ho ... | 2005 | 15890961 |
| complete nucleotide sequence of the rna2 of the crinivirus tomato chlorosis virus. | the complete sequence of genomic rna2 of tomato chlorosis virus (tocv; genus crinivirus, family closteroviridae), isolate at80/99 from spain, was determined and compared with those from the other members of the genus sequenced to date. rna2 is 8244 nucleotides (nt) long and putatively encodes nine orfs that encompass the hallmark gene array of the family closteroviridae, which includes a heat shock protein 70 family homologue, a 59 kda protein, the coat protein, and a diverged coat protein. phyl ... | 2006 | 16374719 |
| localization of sweet potato chlorotic stunt virus (spcsv) in synergic infection with potyviruses in sweet potato. | among diseases reported worldwidely for sweet potato (ipomoea batatas (l) lam) crop, one of the most frequent is the sweet potato virus disease (spvd), caused by sweet potato chlorotic stunt virus (spcsv) and sweet potato feathery mottle virus (spfmv) co-infection. in argentina, there exists the sweet potato chlorotic dwarf (spcd), a sweet potato disease caused by triple co-infection with spcsv, spfmv and sweet potato mild speckling virus (spmsv). both diseases cause a synergism between the poty ... | 2007 | 17665636 |
| analysis of gene content in sweet potato chlorotic stunt virus rna1 reveals the presence of the p22 rna silencing suppressor in only a few isolates: implications for viral evolution and synergism. | sweet potato chlorotic stunt virus (genus crinivirus) belongs to the family closteroviridae, members of which have a conserved overall genomic organization but are variable in gene content. in the bipartite criniviruses, heterogeneity is pronounced in the 3'-proximal region of rna1, which in sweet potato chlorotic stuat virus (spcsv) encodes two novel proteins, rnase3 (rnase iii endonuclease) and p22 (rna silencing suppressor). this study showed that two ugandan spcsv isolates contained the p22 ... | 2008 | 18198389 |
| elimination of two viruses which interact synergistically from sweetpotato by shoot tip culture and cryotherapy. | sweet potato chlorotic stunt virus (spcsv; closteroviridae) and sweet potato feathery mottle virus (spfmv; potyviridae) interact synergistically and cause severe diseases in co-infected sweetpotato plants (ipomoea batatas). sweetpotato is propagated vegetatively and virus-free planting materials are pivotal for sustainable production. using cryotherapy, spcsv and spcsv were eliminated from all treated single-virus-infected and co-infected shoot tips irrespective of size (0.5-1.5mm including 2-4 ... | 2008 | 18786569 |
| natural wild hosts of sweet potato feathery mottle virus show spatial differences in virus incidence and virus-like diseases in uganda. | sweet potato feathery mottle virus (spfmv, genus potyvirus) is globally the most common pathogen of sweetpotato. an east african strain of spfmv incites the severe 'sweetpotato virus disease' in plants co-infected with sweet potato chlorotic stunt virus and threatens subsistence sweetpotato production in east africa; however, little is known about its natural hosts and ecology. in all, 2,864 wild plants growing in sweetpotato fields or in their close proximity in uganda were observed for virus-l ... | 2008 | 18944287 |
| molecular characterization of the cucurbit yellow stunting disorder virus coat protein gene. | abstract cucurbit yellow stunting disorder virus (cysdv) is a partially characterized bipartite closterovirus transmitted by the tobacco whitefly (bemisia tabaci). cysdv has emerged as a serious pathogen in southeastern spain and the mediterranean region, causing yellowing disease of cucumber and melon crops. using a modified reverse-transcription polymerase chain reaction protocol with gel-extracted dsrna templates, fragments of cysdv rna2 were amplified and cloned. sequence analysis of the clo ... | 1999 | 18944661 |
| rna silencing-mediated resistance to a crinivirus (closteroviridae) in cultivated sweet potato (ipomoea batatas l.) and development of sweet potato virus disease following co-infection with a potyvirus. | sweet potato chlorotic stunt virus (spcsv; genus crinivirus, family closteroviridae) is one of the most important pathogens of sweet potato (ipomoea batatas l.). it can reduce yields by 50% by itself and cause various synergistic disease complexes when co-infecting with other viruses, including sweet potato feathery mottle virus (spfmv; genus potyvirus, family potyviridae). because no sources of true resistance to spcsv are available in sweet potato germplasm, a pathogen-derived transgenic resis ... | 2008 | 19018990 |
| elimination of antiviral defense by viral rnase iii. | sweet potato (ipomoea batatas) is an important subsistence and famine reserve crop grown in developing countries where sweet potato chlorotic stunt virus (spcsv; closteroviridae), a single-stranded rna (ssrna) crinivirus, synergizes unrelated viruses in co-infected sweet potato plants. the most severe disease and yield losses are caused by co-infection with spcsv and a potyvirus, sweet potato feathery mottle virus (spfmv; potyviridae). potyviruses synergize unrelated viruses by suppression of rn ... | 2009 | 19515815 |
| cucurbit yellow stunting disorder virus p25 is a suppressor of post-transcriptional gene silencing. | post-transcriptional gene silencing (ptgs) degrades rna in a sequence-specific manner and is utilised by plants as a natural defence mechanism against virus invaders. two members of the genus crinivirus have been reported to encode suppressors and counter ptgs: sweet potato chlorotic stunt virus p22 and tomato chlorosis virus (tocv) p22, coat protein and coat protein minor. using an agrobacterium-mediated transient assay on nicotiana benthamiana wildtype and 16c plants, we screened four cucurbit ... | 2009 | 19540278 |
| unravelling the genetic diversity of the three main viruses involved in sweet potato virus disease (spvd), and its practical implications. | summary sweetpotato (ipomoea batatas) is a widely grown food crop, in which the most important diseases are caused by viruses. genetic variability of three widely distributed sweetpotato viruses was analysed using data from 46 isolates of sweet potato feathery mottle virus (spfmv), 16 isolates of sweet potato mild mottle virus (spmmv) and 25 isolates of sweet potato chlorotic stunt virus (spcsv), of which 19, seven and six isolates, respectively, are newly characterized. division of spfmv into f ... | 2005 | 20565651 |
| sequence characterization of a peruvian isolate of sweet potato chlorotic stunt virus: further variability and a model for p22 acquisition. | sweet potato chlorotic stunt virus (spcsv) is probably the most important virus infecting sweetpotato worldwide, causing severe synergistic disease complexes with several co-infecting viruses. to date only one isolate (ug), corresponding to the ea strain has been completely sequenced. it was later shown to be unusual in that, in contrast to most isolates, it encoded an additional p22 protein at the 3' end of rna1. we report the complete sequence and genome organization of a peruvian isolate of s ... | 2011 | 21262288 |
| distinct cavemoviruses interact synergistically with sweet potato chlorotic stunt virus (genus crinivirus) in cultivated sweet potato. | two serologically unrelated sweet potato viruses causing symptoms of vein clearing in the indicator plant ipomoea setosa were isolated and their genomes have been sequenced. they are associated with symptomless infections in sweet potato but distinct vein-clearing symptoms and higher virus titres were observed when these viruses co-infected with sweet potato chlorotic stunt virus (spcsv), a virus that is distributed worldwide and is a mediator of severe virus diseases in this crop. molecular cha ... | 2011 | 21307225 |
| development of transgenic sweet potato with multiple virus resistance in south africa (sa). | multiple infections of sweet potato feathery mottle virus (spfmv), sweet potato chlorotic stunt virus (spcsv), sweet potato virus g (spvg) and sweet potato mild mottle virus (spmmv) cause a devastating synergistic disease complex of sweet potato (ipomoea batatas lam.) in kwazulu-natal, south africa. in order to address the problem of multiple virus infections and synergism, this study aimed to develop transgenic sweet potato (cv. blesbok) plants with broad virus resistance. coat protein gene seg ... | 2014 | 24158330 |
| mixed infections of four viruses, the incidence and phylogenetic relationships of sweet potato chlorotic fleck virus (betaflexiviridae) isolates in wild species and sweetpotatoes in uganda and evidence of distinct isolates in east africa. | viruses infecting wild flora may have a significant negative impact on nearby crops, and vice-versa. only limited information is available on wild species able to host economically important viruses that infect sweetpotatoes (ipomoea batatas). in this study, sweet potato chlorotic fleck virus (spcfv; carlavirus, betaflexiviridae) and sweet potato chlorotic stunt virus (spcsv; crinivirus, closteroviridae) were surveyed in wild plants of family convolvulaceae (genera astripomoea, ipomoea, hewittia ... | 2016 | 28005969 |
| viral rnase3 co-localizes and interacts with the antiviral defense protein sgs3 in plant cells. | sweet potato chlorotic stunt virus (spcsv; family closteroviridae) encodes a class 1 rnase iii endoribonuclease (rnase3) that suppresses post-transcriptional rna interference (rnai) and eliminates antiviral defense in sweetpotato plants (ipomoea batatas). for rnai suppression, rnase3 cleaves double-stranded small interfering rnas (ds-sirna) and long dsrna to fragments that are too short to be utilized in rnai. however, rnase3 can suppress only rnai induced by sense rna. sense-mediated rnai invol ... | 2016 | 27391019 |
| detection of sweet potato virus c, sweet potato virus 2 and sweet potato feathery mottle virus in portugal. | field sweet potato plants showing virus-like symptoms, as stunting, leaf distortion, mosaic and chlorosis, were collected in southwest portugal and tested for the presence of four potyviruses, sweet potato virus c (spvc), sweet potato virus 2 (spv2), sweet potato feathery mottle virus (spfmv), sweet potato virus g (spvg), and the crinivirus sweet potato chlorotic stunt virus (spcsv). dsrna fractions were extracted from symptomatic leaves and used as templates in single and multiplex rt-pcr assay ... | 2015 | 26104336 |
| control of sweet potato virus diseases. | sweet potato (ipomoea batatas) is ranked seventh in global food crop production and is the third most important root crop after potato and cassava. sweet potatoes are vegetative propagated from vines, root slips (sprouts), or tubers. therefore, virus diseases can be a major constrain, reducing yields markedly, often more than 50%. the main viruses worldwide are sweet potato feathery mottle virus (spfmv) and sweet potato chlorotic stunt virus (spcsv). effects on yields by spfmv or spcsv alone are ... | 2015 | 25591876 |
| variation in virus symptom development and root architecture attributes at the onset of storage root initiation in 'beauregard' sweetpotato plants grown with or without nitrogen. | it has been shown that virus infections, often symptomless, significantly limit sweetpotato productivity, especially in regions characterized by low input agricultural systems. in sweetpotatoes, the successful emergence and development of lateral roots (lrs), the main determinant of root architecture, determines the competency of adventitious roots to undergo storage root initiation. this study aimed to investigate the effect of some plant viruses on root architecture attributes during the onset ... | 2014 | 25243579 |
| synergistic interactions of begomoviruses with sweet potato chlorotic stunt virus (genus crinivirus) in sweet potato (ipomoea batatas l.). | three hundred and ninety-four sweet potato accessions from latin america and east africa were screened by polymerase chain reaction (pcr) for the presence of begomoviruses, and 46 were found to be positive. all were symptomless in sweet potato and generated leaf curling and/or chlorosis in ipomoea setosa. the five most divergent isolates, based on complete genome sequences, were used to study interactions with sweet potato chlorotic stunt virus (spcsv), known to cause synergistic diseases with o ... | 2015 | 25187172 |
| complete genomic sequence and comparative analysis of the genome segments of sweet potato chlorotic stunt virus in china. | sweet potato chlorotic stunt virus (family closteroviridae, genus crinivirus) features a large bipartite, single-stranded, positive-sense rna genome. to date, only three complete genomic sequences of spcsv can be accessed through genbank. spcsv was first detected from china in 2011, only partial genomic sequences have been determined in the country. no report on the complete genomic sequence and genome structure of chinese spcsv isolates or the genetic relation between isolates from china and ot ... | 2014 | 25170926 |
| genetic variability and evolutionary implications of rna silencing suppressor genes in rna1 of sweet potato chlorotic stunt virus isolates infecting sweetpotato and related wild species. | the bipartite single-stranded rna genome of sweet potato chlorotic stunt virus (spcsv, genus crinivirus; closteroviridae) encodes a class 1 rnase iii (rnase3), a putative hydrophobic protein (p7) and a 22-kda protein (p22) from genes located in rna1. rnase3 and p22 suppress rna silencing, the basal antiviral defence mechanism in plants. rnase3 is sufficient to render sweetpotato (ipomoea batatas) virus-susceptible and predisposes it to development of severe diseases following infection with unre ... | 2013 | 24278443 |
| binding and processing of small dsrna molecules by the class 1 rnase iii protein encoded by sweet potato chlorotic stunt virus. | sweet potato chlorotic stunt virus (spcsv; genus crinivirus, family closteroviridae) causes heavy yield losses in sweet potato plants co-infected with other viruses. the dsrna-specific class 1 rnase iii-like endoribonuclease (rnase3) encoded by spcsv suppresses post-transcriptional gene silencing and eliminates antiviral defence in sweet potato plants in an endoribonuclease activity-dependent manner. rnase3 can cleave long dsrna molecules, synthetic small interfering rnas (sirnas), and plant- an ... | 2014 | 24187016 |
| one-step reverse transcription loop mediated isothermal amplification assay for sensitive and rapid detection of cucurbit chlorotic yellows virus. | a reverse transcription loop-mediated isothermal amplification (rt-lamp) assay was developed for the detection of cucurbit chlorotic yellows virus (ccyv). in this procedure, a set of four primers matching a total of six sequences in the coat protein gene region of ccyv was synthesized for the rt-lamp assay using total rna extracted from ccyv-infected melon leaf tissues, and the optimum reaction temperature and assay time were determined. the sensitivity assay showed that the virus was detectable ... | 2014 | 24056260 |
| complete genome sequences of two sweet potato chlorotic stunt virus isolates from china. | sweet potato chlorotic stunt virus (spcsv) was first detected in china in 2010, and several partial sequences have been determined for chinese spcsv isolates. this report describes the complete genome sequences of two spcsv isolates from the guangdong and jiangsu provinces and will be valuable for understanding the characteristics of spcsvs in china. | 2013 | 23661487 |
| molecular variability of sweet potato chlorotic stunt virus (spcsv) and five potyviruses infecting sweet potato in china. | to obtain a better understanding of the molecular variation of sweet potato viruses in china, 131 samples were collected from symptomatic sweet potato plants and used for rt-pcr analysis of the heat shock protein 70 (hsp70) gene sequence of sweet potato chlorotic stunt virus (spcsv) and the coat protein (cp) gene sequences of five potyviruses (spfmv, spvc, spvg, splv and spv2). the hsp70 sequences that were obtained provided evidence for the presence of two distinct strains of spcsv. analysis of ... | 2013 | 23053527 |
| viruses in sweetpotato. | sweetpotato in the mediterranean is mainly grown in egypt, spain, portugal, and israel. yields vary from 34 tons/ha in israel to 7.8 tons/ha in portugal. as sweetpotatoes are vegetatively propagated, the differences in yields are probably due to the quality in the propagation material, mainly infection by various viruses. the main viruses affecting sweetpotato in mediterranean countries are sweet potato feathery mottle virus potyvirus, sweet potato sunken vein virus (sweet potato chlorotic stunt ... | 2012 | 22682172 |