| indian cassava mosaic virus: ultrastructure of infected cells. | ultrastructural examination of leaf tissue of nicotiana benthamiana infected with indian cassava mosaic virus (icmv) revealed abnormalities in phloem and, occasionally, xylem cells. nuclei contained granular inclusion bodies which seemed to be largely composed of virus-like particles and were shown by immunogold labelling (igl) to be rich in icmv coat protein. later in infection, hollow spheres made up of fibrillar material were produced. virus coat protein was not a necessary component of these ... | 1989 | 2794977 |
| biolistic infection of cassava using cloned components of indian cassava mosaic virus. | cassava mosaic disease (cmd) is a major constraint to cassava production in africa and asia. of the two begomoviruses associated with cmd on the indian subcontinent, indian cassava mosaic virus (icmv) and sri lankan cassava mosaic virus, only the latter has been successfully reintroduced into cassava to resolve the aetiology of the disease. here, we report the complete nucleotide sequence of an icmv isolate from maharashtra (icmv-[mah2]), central india. biolistic inoculation of the cloned compon ... | 2005 | 15824887 |
| the agrobacterium tumefaciens ti plasmid virulence gene vire2 reduces sri lankan cassava mosaic virus infection in transgenic nicotiana benthamiana plants. | cassava mosaic disease is a major constraint to cassava cultivation worldwide. in india, the disease is caused by indian cassava mosaic virus (icmv) and sri lankan cassava mosaic virus (slcmv). the agrobacterium ti plasmid virulence gene vire2, encoding a nuclear-localized, single-stranded dna binding protein, was introduced into nicotiana benthamiana to develop tolerance against slcmv. leaf discs of transgenic n. benthamiana plants, harboring the vire2 gene, complemented a vire2 mutation in a. ... | 2015 | 26008704 |
| pcr-rflp analysis indicates that recombination might be a common occurrence among the cassava infecting begomoviruses in india. | cassava mosaic disease (cmd) is caused in india by two bipartite begomoviruses, indian cassava mosaic virus (icmv), and sri lankan cassava mosaic virus (slcmv). polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) was used as a rapid means of investigating the molecular diversity of icmv and slcmv in 38 samples of cmd-affected cassava plants under field conditions in new areas of cassava cultivation, along with traditional areas in southern india. a very large proportion ... | 2012 | 22696049 |
| dna-a of a highly pathogenic indian cassava mosaic virus isolated from jatropha curcas causes symptoms in nicotiana benthamiana. | jatropha curcas mosaic disease (jcmd) is a newly emerging disease that has been reported in africa and india. here, we report the complete nucleotide sequence of a new indian cassava mosaic virus isolate (icmv-sg) from singapore. infection of icmv-sg showed more severe jcmd in jatropha curcas and nicotiana benthamiana than the other icmv isolates reported previously, though icmv-sg shares high sequence identity with the other icmv isolates. agroinfectious dna-a alone sufficiently induced systemi ... | 2014 | 24445901 |
| engineering geminivirus resistance in jatropha curcus. | jatropha curcus is a good candidate plant for biodiesel production in tropical and subtropical regions. however, j. curcus is susceptible to the geminivirus indian cassava mosaic virus (icmv), and frequent viral disease outbreaks severely limit productivity. therefore the development of j. curcus to carry on durable virus resistance remains crucial and poses a major biotechnological challenge. | 2014 | 25352912 |
| molecular characterization of a new begomovirus associated with leaf yellow mosaic disease of jatropha curcas in india. | during a survey in june 2011, severe leaf yellow mosaic disease was observed on about 45 % plants of jatropha curcas growing in the katerniaghat wildlife sanctuary in india. an association of a begomovirus with disease was detected in 15 out of 20 samples by pcr using begomovirus genus-specific primers and total dna isolated from symptomatic leaf samples. for identification of the begomovirus, the complete genome was amplified using a phi-29 dna-polymerase-based rolling-circle amplification kit ... | 2015 | 25716923 |
| emergence of a latent indian cassava mosaic virus from cassava which recovered from infection by a non-persistent sri lankan cassava mosaic virus. | the major threat for cassava cultivation on the indian subcontinent is cassava mosaic disease (cmd) caused by cassava mosaic geminiviruses which are bipartite begomoviruses with dna a and dna b components. indian cassava mosaic virus (icmv) and sri lankan cassava mosaic virus (slcmv) cause cmd in india. two isolates of slcmv infected the cassava cultivar sengutchi in the fields near malappuram and thiruvananthapuram cities of kerala state, india. the malappuram isolate was persistent when mainta ... | 2016 | 27690084 |
| molecular studies on the transmission of indian cassava mosaic virus (icmv) and sri lankan cassava mosaic virus (slcmv) in cassava by bemisia tabaci and cloning of icmv and slcmv replicase gene from cassava. | cassava mosaic disease, caused by cassava mosaic geminiviruses are transmitted by bemisia tabaci. the b. tabaci adults from colonies reared on virus free cassava plant produced from apical meristem culture was studied to determine their ability to transmit indian cassava mosaic virus (icmv) and sri lankan cassava mosaic virus (slcmv) from cassava to cassava. virus free plants were confirmed by polymerase chain reaction (pcr) using geminivirus degenerate primers. the virus acquisition access peri ... | 2012 | 22302313 |
| form follows function in geminiviral minichromosome architecture. | a comprehensive survey on the viral minichromosomes of the begomoviruses abutilon mosaic virus, tomato yellow leaf curl sardinia virus, african cassava mosaic virus, indian cassava mosaic virus (family geminiviridae) during the course of infections in nicotiana benthamiana is summarized. using optimized one-dimensional and two-dimensional gel systems combined with blot hybridization and a standardized evaluation, discrete and heterogeneous virus-specific signals with different dna forms were com ... | 2015 | 25445344 |
| a new strain of indian cassava mosaic virus causes a mosaic disease in the biodiesel crop jatropha curcas. | jatropha curcas mosaic disease is a newly emerging disease that challenges the productivity of a prospective biofuel crop, j. curcas. the aetiology of this disease has not been resolved. here, we report the complete nucleotide sequences of a jatropha virus isolated from dharwad, southern india. phylogenetic analysis of the virus genome suggests it is a new strain of indian cassava mosaic virus. agroinfiltration of the two cloned viral dna components produced systemic infection and typical mosaic ... | 2010 | 20224893 |
| the oligomeric rep protein of mungbean yellow mosaic india virus (mymiv) is a likely replicative helicase. | geminiviruses replicate by rolling circle mode of replication (rcr) and the viral rep protein initiates rcr by the site-specific nicking at a conserved nonamer (taatatt downward arrow ac) sequence. the mechanism of subsequent steps of the replication process, e.g. helicase activity to drive fork-elongation, etc. has largely remained obscure. here we show that rep of a geminivirus, namely, mungbean yellow mosaic india virus (mymiv), acts as a replicative helicase. the rep-helicase, requiring > or ... | 2006 | 17142233 |
| deletion and recombination events between the dna-a and dna-b components of indian cassava-infecting geminiviruses generate defective molecules in nicotiana benthamiana. | cloned dna-b components, belonging to the bipartite begomoviruses indian cassava mosaic virus (icmv) and sri lankan cassava mosaic virus (slcmv), family geminiviridae, when co-inoculated along with previously cloned dna-a components of the respective viruses onto the experimental host nicotiana benthamiana, generated defective dnas (def-dna) ranging in size from 549 to 1555 nucleotides. all the cloned def-dnas contained the common region (cr) as well as portions of either dna-a or dna-b and, in ... | 2007 | 17109983 |
| tissue and cell tropism of indian cassava mosaic virus (icmv) and its av2 (precoat) gene product. | in order to establish defined viruses for challenging plants in resistance breeding programmes, indian cassava mosaic virus (icmv; family geminiviridae) dna clones were modified to monitor viral spread in plants by replacing the coat protein gene with the green fluorescent protein (gfp) reporter gene. comparative in situ hybridization experiments showed that icmv was restricted to the phloem in cassava and tobacco. gfp-tagged virus spread similarly, resulting in homogeneous fluorescence within n ... | 2007 | 17049959 |
| biodiversity and recombination of cassava-infecting begomoviruses from southern india. | cassava mosaic disease (cmd) is caused by various begomoviruses of the family geminiviridae leading to considerable crop losses in africa and asia. recombination between their genomic components has generated new pathotypes with enhanced virulence in africa. here, we report about a survey on the biodiversity of begomoviruses in cassava from southern india (tamil nadu and kerala states) performed in 2001 and 2002. viral dna a components from stem cuttings were analysed using polymerase chain reac ... | 2006 | 16132175 |
| both indian cassava mosaic virus and sri lankan cassava mosaic virus are found in india and exhibit high variability as assessed by pcr-rflp. | the biodiversity of geminiviruses associated with the cassava mosaic disease (cmd) in india was investigated using pcr to specifically amplify the dna of indian cassava mosaic virus (icmv) or sri lankan cassava mosaic virus (slcmv) and also by using pcr to amplify specific viral genes, followed by digestion with different restriction endonucleases to obtain polymorphic patterns (pcr-rflp). results showed that both icmv and slcmv were present in mosaic-affected cassava; icmv was geographically re ... | 2005 | 15503225 |
| differential roles of ac2 and ac4 of cassava geminiviruses in mediating synergism and suppression of posttranscriptional gene silencing. | posttranscriptional gene silencing (ptgs) in plants is a natural defense mechanism against virus infection. in mixed infections, virus synergism is proposed to result from suppression of the host defense mechanism by the viruses. synergistic severe mosaic disease caused by simultaneous infection with isolates of the cameroon strain of african cassava mosaic virus (acmv-[cm]) and east african cassava mosaic cameroon virus (eacmcv) in cassava and tobacco is characterized by a dramatic increase in ... | 2004 | 15308741 |
| begomoviruses from mungbeans in pakistan: epitope profiles, dna a sequences and phylogenetic relationships. | monoclonal antibodies raised against particles of african cassava mosaic virus, indian cassava mosaic virus or okra leaf curl virus were used to test samples collected in pakistan from begomovirus-infected plants. epitope profiles obtained from cucurbits resembled those previously reported for pakistani begomoviruses. in contrast, epitope profiles obtained from legumes showed little diversity and were quite distinct from these. dna with nucleotide sequences typical of begomovirus dna a component ... | 2004 | 15045567 |
| co-adaptation between cassava mosaic geminiviruses and their local vector populations. | four cassava mosaic geminivirus (cmg) isolates; african cassava mosaic virus from namulonge, uganda (acmv-[nam]), east african cassava mosaic virus from mtwara, tanzania (eacmv-[mtw]), eacmv-uganda from namulonge (eacmv-ug[nam]) and indian cassava mosaic virus from trivandrum, india (icmv-[tri]) were compared for their ability to be transmitted by four colonies of cassava whitefly, bemisia tabaci (gennadius), collected from namulonge (nam), mtwara (mtw), kumasi (kum) and trivandrum (tri). with 2 ... | 2002 | 12076831 |
| characterisation of sri lankan cassava mosaic virus and indian cassava mosaic virus: evidence for acquisition of a dna b component by a monopartite begomovirus. | two bipartite begomoviruses, indian cassava mosaic virus (icmv) and sri lankan cassava mosaic virus (slcmv), have been isolated from mosaic-diseased cassava originating from central india and sri lanka, respectively. icmv was transmitted with low efficiency from cassava to nicotiana benthamiana by sap inoculation to give leaf curl symptoms. slcmv was much more virulent in this host, producing severe stunting, leaf curl, and chlorosis. these symptoms were reproduced when their cloned genomic comp ... | 2002 | 11853400 |
| nucleotide sequence and intergeminiviral homologies of the dna-a of papaya leaf curl geminivirus from india. | coat protein gene, rep protein gene and intergenic region of the genome of a whitefly transmitted geminivirus (wtg) causing severe leaf curl in papaya plants were pcr amplified, cloned and sequenced. comparison of the amino acid sequence of the putative coat protein product of papaya leaf curl virus (plcv) with some other mono and bipartite wtgs revealed a maximum of 89.8% homology with indian cassava mosaic virus. the genomic organization of plcv-india is similar to other wtgs with bipartite ge ... | 1998 | 9635134 |
| specificity of bipartite geminivirus movement proteins. | pseudorecombinants produced by exchanging genome components (dnas a and b) of the geminiviruses african cassava mosaic virus (acmv) and indian cassava mosaic virus (icmv), acmv, and tomato golden mosaic virus (tgmv), and tgmv and abutilon mosaic virus (abmv) are not infectious in their common host nicotiana benthamiana. in each case, dna a was unable to trans-replicate the heterogenomic dna b component in a n. benthamiana leaf disc assay. the non-viability of the pseudorecombinants has been expl ... | 1993 | 8372440 |
| nucleotide sequence evidence for the occurrence of three distinct whitefly-transmitted geminiviruses in cassava. | the complete nucleotide sequence of the dna of indian cassava mosaic virus (icmv) and a key part of that of a group b isolate of african cassava mosaic virus from malawi (acmv-m) were determined and compared at the nucleotide and encoded amino acid levels with the published sequences of an acmv group a isolate (acmv-k) and other whitefly-transmitted gemini-viruses (wtgs). the dna of icmv consists of two circular single-stranded molecules, dna-a [2815 nucleotides (nt)] and dna-b (2645 nt), which ... | 1993 | 8245859 |
| tomato leaf curl geminivirus from india has a bipartite genome and coat protein is not essential for infectivity. | genomes of two isolates of tomato leaf curl geminivirus from india (tolcv-india) have been sequenced. tolcv-india contains a and b components, both of which are required for systemic movement and symptom development. the two isolates have 94% sequence identify but one isolate gave mild symptoms in nicotiana benthamiana and tomato. the genome organization of tolcv-india is similar to other whitefly-transmitted geminiviruses (wtgs) with bipartite genomes. however, it contains an additional orf, av ... | 1995 | 7844539 |
| chinese squash leaf curl virus: a new whitefly-transmitted geminivirus. | coat protein (cp) gene of the chinese squash leaf curl virus (sqlcv-c) was amplified through pcr, cloned and completely sequenced. based on the comparisons at the levels of both cp gene nucleotide and cp-deduced amino acid sequences with other geminiviruses, sqlcv-c is confirmed to be distinct from the american squash leaf curl virus (sqlcv-e). it is a new geminivirus transmitted by whitefly bemisia tabaci, which infects dicotyledonous plants and is more closely related to the indian cassava mos ... | 1995 | 7755872 |
| molecular cloning of indian tomato leaf curl virus genome following a simple method of concentrating the supercoiled replicative form of viral dna. | dna-a and dna-b components of the genome of a whitefly transmitted virus causing yellowing and leaf curl in tomato (itlcv) were cloned following a simple procedure for isolation of the double stranded replicative form of viral dna from infected tomato plants. the method is based on extraction of total dna from infected plants followed by concentration of the double stranded replicative form of viral dna by an alkaline denaturation procedure identical to that used for isolation of plasmid dna fro ... | 1995 | 7738150 |
| serological relationships and epitope profiles of isolates of okra leaf curl geminivirus from africa and the middle east. | a panel of seven murine monoclonal antibodies (mabs) was raised against particles of okra leaf curl virus (olcv), a whitefly-transmitted geminivirus which is prevalent in west africa. the mabs detected at least six distinguishable epitopes, two continuous and four discontinuous. in tests with these mabs, relatively little antigenic variation was found among 24 olcv isolates from burkina faso, chad, ghana, ivory coast, nigeria, oman and saudi arabia, each virus isolate reacting with at least five ... | 1993 | 7506936 |