Begomoviruses are considered as one of the most notorious plant viruses worldwide, which cause substantial economic losses to various field crops. Management of begomoviruses has become a challenge due to the continuous evolution and the... more
Begomoviruses are considered as one of the most notorious plant viruses worldwide, which cause substantial economic losses to various field crops. Management of begomoviruses has become a challenge due to the continuous evolution and the emergence of new strains. Bemisia tabaci is globally known to be the key vector of begomoviruses, having relatively high reproductivity, fast dispersal ability, high survival rate due to its polyphagous nature and high resistance to various groups of insecticides. Continuous transmission of begomoviruses by the vector has led to the development and spread of epidemics of various diseases worldwide. In this review, we have critically analyzed the various dynamics which facilitate the diversity of begomoviruses through their vector. The interaction of begomovirus-whitefly leads to continuous research activities regarding management of both virus and its vector, thus opening exciting new horizons to formulate potential control strategies to ensure a di...
Okra leaf curl geminivirus (Family Geminivirdae: Genus Begomovirus) was isolated for the first time in Saudi Arabia, from okra (Abelmoschus esculentus L.) plants grown in the greenhouse of the Agricultural and Veterinary Experimental... more
Okra leaf curl geminivirus (Family Geminivirdae: Genus Begomovirus) was isolated for the first time in Saudi Arabia, from okra (Abelmoschus esculentus L.) plants grown in the greenhouse of the Agricultural and Veterinary Experimental Station in Hofuf, Al-Hasa, King Faisal Univ. Okra plants were heavily infested with Bemisia tabaci Genn. showing symptoms of severe stunting, leaf crumpling, curling, malformation, vein enation and veinal necrosis. The isolated virus was designated as okra leaf curl geminivirus-Saudi Arabian-isolate (OLCV-SA). Disease incidence ranged from 15-70 % and appeared related to the age of plants and infection time. In whiteflies transmission trials, a single whitefly was able to transmit OLCV-SA applying 48hr for both acquisition and inoculation access (AAP and IAP, respectively) periods. Extending both AAP and IAP increased the transmission efficiency from 13.3-93.3 % applying an IAP and AAP for 48hr. Purified OLCV-SA formed peak with Amax and Amin of 258, 24...
The location of tomato mottle virus (ToMoV) and cabbage leaf curl virus (CabLCV) (Geminiviridae, genus Begomovirus) in the whitefly vector Bemisia tabaci B-biotype (Homoptera: Aleyrodidae) was elucidated using a novel technique... more
The location of tomato mottle virus (ToMoV) and cabbage leaf curl virus (CabLCV) (Geminiviridae, genus Begomovirus) in the whitefly vector Bemisia tabaci B-biotype (Homoptera: Aleyrodidae) was elucidated using a novel technique incorporating indirect immunofluorescent labeling in freshly dissected whiteflies. Begomoviruses were visualized in the whitefly by indirect-fluorescent-microscopy. Polyclonal and monoclonal primary antibodies were used to successfully detect both ToMoV and CabLCV. Both begomoviruses were located in the anterior region of the midgut and filter-chamber of adult whiteflies, with ToMoV detected in the salivary glands. CabLCV was detected at a greater frequency than ToMoV, with a positive detection of 16% (89 out of 560) for CabLCV and 3% (25 out of 840) for ToMoV. Possible sites involved in geminivirus transport from the gut lumen of whiteflies into the hemocoel were located in the filter-chamber and anterior portion of the midgut. The location of these begomoviruses suggests a possible scenario of virus movement through the whitefly.
Begomoviruses are considered as one of the most notorious plant viruses worldwide, which cause substantial economic losses to various field crops. Management of begomoviruses has become a challenge due to the continuous evolution and the... more
Begomoviruses are considered as one of the most notorious plant viruses worldwide, which cause substantial economic losses to various field crops. Management of begomoviruses has become a challenge due to the continuous evolution and the emergence of new strains. Bemisia tabaci is globally known to be the key vector of begomoviruses, having relatively high reproductivity, fast dispersal ability, high survival rate due to its poly-phagous nature and high resistance to various groups of insecticides. Continuous transmission of begomoviruses by the vector has led to the development and spread of epidemics of various diseases worldwide. In this review, we have critically analyzed the various dynamics which facilitate the diversity of begomoviruses through their vector. The interaction of begomovirus-whitefly leads to continuous research activities regarding management of both virus and its vector, thus opening exciting new horizons to formulate potential control strategies to ensure a disease-free cropping environment.
Okra leaf curl geminivirus (Family Geminivirdae: Genus Begomovirus) was isolated for the first time in Saudi Arabia, from okra (Abelmoschus esculentus L.) plants grown in the greenhouse of the Agricultural and Veterinary Experimental... more
Okra leaf curl geminivirus (Family Geminivirdae: Genus Begomovirus) was isolated for the first time in Saudi Arabia, from okra (Abelmoschus esculentus L.) plants grown in the greenhouse of the Agricultural and Veterinary Experimental Station in Hofuf, Al-Hasa, King Faisal Univ. Okra plants were heavily infested with Bemisia tabaci Genn. showing symptoms of severe stunting, leaf crumpling, curling, malformation, vein enation and veinal necrosis. The isolated virus was designated as okra leaf curl geminivirus-Saudi Arabian-isolate (OLCV-SA). Disease incidence ranged from 15-70 % and appeared related to the age of plants and infection time. In whiteflies transmission trials, a single whitefly was able to transmit OLCV-SA applying 48hr for both acquisition and inoculation access (AAP and IAP, respectively) periods. Extending both AAP and IAP increased the transmission efficiency from 13.3-93.3 % applying an IAP and AAP for 48hr. Purified OLCV-SA formed peak with Amax and Amin of 258, 24...
Whitefly cells were inoculated with IIV-6 developed cytopathic effects (CPE) which indicated virus replication, the BtB-2.97 cell line, Infected cells became more rounded and developed inclusions that increased in size over the infection... more
Whitefly cells were inoculated with IIV-6 developed cytopathic effects (CPE) which indicated virus replication, the BtB-2.97 cell line, Infected cells became more rounded and developed inclusions that increased in size over the infection period. Examination of infected cells by electron microscopy revealed that an electron-dense virogenic stroma had formed and that the icosahedral virus accumulated only in the cytoplasm, which is characteristic of iridoviruses. Immunofluorescent staining was used to detect virus structural proteins within the cells. Whitefly cells were grown on coverslips and infected with IIV-6 (multiplicity of infection (moi) of 10). The coverslips were removed at various times postinfection, fixed in 3.7% formaldehyde, and permeabilized for 10 min in acetone at 220°C. The cells were probed with an anti-IIV-6 antibody (a gift from Dr. J. Kalmakoff) for 30 min (1:500 dilution), then probed with an anti-rabbit antibody labeled with Alexa Fluor 488 (Molecular Probes Inc.) (30 min, 1:200 dilution), and counterstained with 300 nM 49,6-diamidino-2-phenylindole.
