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Stunt Virus (stunt + virus)
Kinds of Stunt Virus Selected AbstractsHost Range of an Iranian Isolate of Watermelon Chlorotic Stunt Virus as Determined by Whitefly-mediated Inoculation and Agroinfection, and its Geographical DistributionJOURNAL OF PHYTOPATHOLOGY, Issue 8-9 2002K. Bananej Abstract Virus like symptoms appeared on most watermelon plants grown at different locations in southern provinces of Iran. The symptoms included chlorotic patches on leaves, vein yellowing and stunting of watermelon plants. The causal agent of watermelon chlorotic stunt disease was transmitted to healthy watermelon, jimsonweed and bean by the whitefly Bemisia tabaci, but not by sap inoculation. Coat protein and nucleic acid of Watermelon chlorotic stunt virus (WmCSV) were detected in infected plants using a dot-immunobinding assay (DIBA) and squash-blot hybridization, respectively. The data obtained confirmed that watermelon chlorotic stunt disease in Iran is caused by WmCSV. Agroinoculation of some plant species by the cloned genomic components (DNA-A and DNA-B) of a non-sap-transmissible Iranian isolate of WmCSV (WmCSV-Ir) has been demonstrated. Host range studies using agroinoculation indicated that most plant species in the Cucurbitaceae and some species of the Solanaceae are susceptible to WmCSV-Ir. Infection of agroinoculated plants was confirmed by DIBA and polymerase chain reaction. The virus from agroinfected plants was transmissible by the whitefly Bemisia tabaci. Results obtained from a limited survey during 1997,2000 indicated the presence of WmCSV-Ir in some watermelon-growing provinces of southern but not in northern, central, and north-eastern provinces of Iran. WmCSV has apparently not yet spread to these regions. [source] Identification of Three Strains of a Virus Associated with Cassava Plants Affected by Frogskin DiseaseJOURNAL OF PHYTOPATHOLOGY, Issue 11-12 2008L. A. Calvert Abstract Cassava Frogskin Disease (CFSD) can cause severe damage to cassava roots and is one of the most important diseases of cassava in Latin America. The principal objective of this study was to identify the causal agent of CFSD. Electron microscopy, viral purifications, double-stranded RNA (dsRNA) analysis, cloning, sequencing, rtPCR and hybridizations were carried out to characterize and associate a novel virus with the disease. Virus-like particles of 70 and 45 nm in diameter were found in affected cassava plants and partially purified preparations respectively. Nine species of dsRNA were associated with this disease and cDNA clones to six genomic segments were synthesized from the purified dsRNAs. The putative proteins predicted from the sequence of the cassava virus cDNA clones have similarity with the P1, P2, P3, P4, P5 and P10 proteins of Rice ragged stunt virus (RRSV). Phylogenic analysis confirmed that this virus is a member of the family Reoviridae and is most closed related to RRSV. Hybridization analyses of dsRNA identified S1, S2, S3, S4, S5 and S10 genomic segments in the CFSD-affected plants, but not in healthy controls. Additionally, 26 isolates were compared using a portion of the putative polymerase gene. The virus was detected in all 26 isolates, and they were classified into three distinct races. The association of this virus with CFSD was strengthened by the detection of this virus in diseased plants collected from different locations throughout Colombia. [source] Host Range of an Iranian Isolate of Watermelon Chlorotic Stunt Virus as Determined by Whitefly-mediated Inoculation and Agroinfection, and its Geographical DistributionJOURNAL OF PHYTOPATHOLOGY, Issue 8-9 2002K. Bananej Abstract Virus like symptoms appeared on most watermelon plants grown at different locations in southern provinces of Iran. The symptoms included chlorotic patches on leaves, vein yellowing and stunting of watermelon plants. The causal agent of watermelon chlorotic stunt disease was transmitted to healthy watermelon, jimsonweed and bean by the whitefly Bemisia tabaci, but not by sap inoculation. Coat protein and nucleic acid of Watermelon chlorotic stunt virus (WmCSV) were detected in infected plants using a dot-immunobinding assay (DIBA) and squash-blot hybridization, respectively. The data obtained confirmed that watermelon chlorotic stunt disease in Iran is caused by WmCSV. Agroinoculation of some plant species by the cloned genomic components (DNA-A and DNA-B) of a non-sap-transmissible Iranian isolate of WmCSV (WmCSV-Ir) has been demonstrated. Host range studies using agroinoculation indicated that most plant species in the Cucurbitaceae and some species of the Solanaceae are susceptible to WmCSV-Ir. Infection of agroinoculated plants was confirmed by DIBA and polymerase chain reaction. The virus from agroinfected plants was transmissible by the whitefly Bemisia tabaci. Results obtained from a limited survey during 1997,2000 indicated the presence of WmCSV-Ir in some watermelon-growing provinces of southern but not in northern, central, and north-eastern provinces of Iran. WmCSV has apparently not yet spread to these regions. [source] Unravelling the genetic diversity of the three main viruses involved in Sweet Potato Virus Disease (SPVD), and its practical implicationsMOLECULAR PLANT PATHOLOGY, Issue 2 2005FRED TAIRO 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 four genetic groups (strains) according to phylogenetic analysis of coat protein (CP) encoding sequences revealed that strain EA contained the East African isolates of SPFMV but none from elsewhere. In contrast, strain RC contained ten isolates from Australia, Africa, Asia and North America. Strain O contained six heterogeneous isolates from Africa, Asia and South America. The seven strain C isolates from Australia, Africa, Asia, and North and South America formed a group that was genetically distant from the other SPFMV strains. SPMMV isolates showed a high level of variability with no discrete strain groupings. SPCSV isolates from East Africa were phylogenetically distant to SPCSV isolates from elsewhere. Only from East Africa were adequate data available for different isolates of the three viruses to estimate the genetic variability of their local populations. The implications of the current sequence information and the need for more such information from most sweetpotato-growing regions of the world are discussed in relation to virus diagnostics and breeding for virus resistance. [source] Cryotherapy of shoot tips: a technique for pathogen eradication to produce healthy planting materials and prepare healthy plant genetic resources for cryopreservationANNALS OF APPLIED BIOLOGY, Issue 3 2009Q.C. Wang Abstract Cryotherapy of shoot tips is a new method for pathogen eradication based on cryopreservation techniques. Cryopreservation refers to the storage of biological samples at ultra-low temperature, usually that of liquid nitrogen (,196°C), and is considered as an ideal means for long-term storage of plant germplasm. In cryotherapy, plant pathogens such as viruses, phytoplasmas and bacteria are eradicated from shoot tips by exposing them briefly to liquid nitrogen. Uneven distribution of viruses and obligate vasculature-limited microbes in shoot tips allows elimination of the infected cells by injuring them with the cryo-treatment and regeneration of healthy shoots from the surviving pathogen-free meristematic cells. Thermotherapy followed by cryotherapy of shoot tips can be used to enhance virus eradication. Cryotherapy of shoot tips is easy to implement. It allows treatment of large numbers of samples and results in a high frequency of pathogen-free regenerants. Difficulties related to excision and regeneration of small meristems are largely circumvented. To date, severe pathogens in banana (Musa spp.), Citrus spp., grapevine (Vitis vinifera), Prunus spp., raspberry (Rubus idaeus), potato (Solanum tuberosum) and sweet potato (Ipomoea batatas) have been eradicated using cryotherapy. These pathogens include nine viruses (banana streak virus, cucumber mosaic virus, grapevine virus A, plum pox virus, potato leaf roll virus, potato virus Y, raspberry bushy dwarf virus, sweet potato feathery mottle virus and sweet potato chlorotic stunt virus), sweet potato little leaf phytoplasma and Huanglongbing bacterium causing ,citrus greening'. Cryopreservation protocols have been developed for a wide variety of plant species, including agricultural and horticultural crops and ornamental plants, and can be used as such or adjusted for the purpose of cryotherapy. [source] Identification and distribution of viruses infecting sweet potato in KenyaANNALS OF APPLIED BIOLOGY, Issue 3 2004E M ATEKA Summary Four hundred and forty-eight symptomatic and 638 asymptomatic samples were collected from sweet potato fields throughout Kenya and analysed serologically using antibodies to Sweet potato feathery mottle virus (SPFMV), Sweet potato chlorotic stunt virus (SPCSV), Sweet potato mild mottle virus (SPMMV), Cucumber mosaic virus (CMV), Sweet potato chlorotic fleck virus (SPCFV), Sweet potato latent virus (SwPLV), Sweet potato caulimo-like virus (SPCaLV), Sweet potato mild speckling virus (SPMSV) and C-6 virus in enzyme-linked immunosorbent assays (ELISA). Only SPFMV, SPMMV, SPCSV, and SPCFV were detected. Ninety-two percent and 25% of the symptomatic and asymptomatic plants respectively tested positive for at least one of these viruses. Virus-infected plants were collected from 89% of the fields. SPFMV was the most common and the most widespread, detected in 74% of the symptomatic plants and 86% of fields surveyed. SPCSV was also very common, being detected in 38% of the symptomatic plants and in 50% of the fields surveyed. SPMMV and SPCFV were detected in only 11% and 3% of the symptomatic plant samples respectively. Eight different combinations of these four viruses were found in individual plants. The combination SPFMV and SPCSV was the most common, observed in 22% of symptomatic plants. Virus combinations were rare in the asymptomatic plants tested. Incidence of virus infection was highest (18%) in Kisii district of Nyanza province and lowest (1%) in Kilifi and Malindi districts of Coast province. [source] A DNA replicon system for rapid high-level production of virus-like particles in plantsBIOTECHNOLOGY & BIOENGINEERING, Issue 4 2009Zhong Huang Abstract Recombinant virus-like particles (VLPs) represent a safe and effective vaccine strategy. We previously described a stable transgenic plant system for inexpensive production and oral delivery of VLP vaccines. However, the relatively low-level antigen accumulation and long-time frame to produce transgenic plants are the two major roadblocks in the practical development of plant-based VLP production. In this article, we describe the optimization of geminivirus-derived DNA replicon vectors for rapid, high-yield plant-based production of VLPs. Co-delivery of bean yellow dwarf virus (BeYDV)-derived vector and Rep/RepA-supplying vector by agroinfiltration of Nicotiana benthamiana leaves resulted in efficient replicon amplification and robust protein production within 5 days. Co-expression of the P19 protein of tomato bush stunt virus, a gene silencing inhibitor, further enhanced VLP accumulation by stabilizing the mRNA. With this system, hepatitis B core antigen (HBc) and Norwalk virus capsid protein (NVCP) were produced at 0.80 and 0.34 mg/g leaf fresh weight, respectively. Sedimentation analysis and electron microscopy of transiently expressed antigens verified the efficient assembly of VLPs. Furthermore, a single replicon vector containing a built-in Rep/RepA cassette without P19 drove protein expression at similar levels as the three-component system. These results demonstrate the advantages of fast and high-level production of VLP-based vaccines using the BeYDV-derived DNA replicon system for transient expression in plants. Biotechnol. Bioeng. 2009;103: 706,714. © 2009 Wiley Periodicals, Inc. [source] | ||||||||||