High Resistance to Cucumber Mosaic Virus Conferred by Satellite RNA and Coat Protein in Transgenic Commercial Tobacco Cultivar G-140

1992 ◽  
Vol 5 (6) ◽  
pp. 460 ◽  
Author(s):  
Y. Yie
Plant Disease ◽  
2006 ◽  
Vol 90 (11) ◽  
pp. 1457-1457 ◽  
Author(s):  
N. Sudhakar ◽  
D. Nagendra-Prasad ◽  
N. Mohan ◽  
K. Murugesan

During a survey in January 2006 near Salem in Tamil Nadu (south India), Cucumber mosaic virus was observed infecting tomatoes with an incidence of more than 70%. Plants exhibiting severe mosaic, leaf puckering, and stunted growth were collected, and the virus was identified using diagnostic hosts, evaluation of physical properties of the virus, compound enzyme-linked immunosorbent assay (ELISA) (ELISA Lab, Washington State University, Prosser), reverse-transcription polymerase chain reaction (RT-PCR), and restriction fragment length polymorphism analysis (DSMZ, S. Winter, Germany). To determine the specific CMV subgroup, total RNA was extracted from 50 infected leaf samples using the RNeasy plant RNA isolation kit (Qiagen, Hilden, Germany) and tested for the presence of the complete CMV coat protein gene using specific primers as described by Rizos et al. (1). A fragment of the coat protein was amplified and subsequently digested with MspI to reveal a pattern of two fragments (336 and 538 bp), indicating CMV subgroup II. No evidence of mixed infection with CMV subgroup I was obtained when CMV isolates representing subgroups I (PV-0419) and II (PV-0420), available at the DSMZ Plant Virus Collection, were used as controls. Only CMV subgroup I has been found to predominantly infect tomato in the Indian subcontinent, although Verma et al. (2) identified CMV subgroup II infecting Pelargonium spp., an ornamental plant. To our knowledge, this is the first report of CMV subgroup II infecting tomato crops in India. References: (1) H. Rizos et al. J. Gen. Virol. 73:2099, 1992. (2) N. Verma et al. J. Biol. Sci. 31:47, 2006.


2004 ◽  
Vol 17 (1) ◽  
pp. 98-108 ◽  
Author(s):  
Fabrizio Cillo ◽  
Mariella M. Finetti-Sialer ◽  
Maria A. Papanice ◽  
Donato Gallitelli

Transgenic tomato (Lycopersicon esculentum Mill. cv. UC82) plants expressing a benign variant of Cucumber mosaic virus satellite RNA (CMV Tfn-satRNA) were generated. The transformed plants did not produce symptoms when challenged with a satRNA-free strain of CMV (CMV-FL). The same plant lines initially were susceptible to necrosis elicited by a CMV strain supporting a necrogenic variant of satRNA (CMV-77), but a phenotype of total recovery from the necrosis was observed in the newly developing leaves. The features of the observed resistance were analyzed and are consistent with two different mechanisms of resistance. In transgenic plants inoculated with CMV-FL strain, the symptomless phenotype was correlated to the down-regulation of CMV by Tfn-satRNA, amplified from the transgene transcripts, as the first resistance mechanism. On the other hand, the delayed resistance to CMV-77 in transgenic tomato lines was mediated by a degradation process that targets satRNAs in a sequence-specific manner. Evidence is provided for a correlation between a reduced accumulation level of transgenic messenger Tfn-satRNA, the accumulation of small (approximately 23 nucleotides) RNAs with sequence homology to satRNAs, the progressively reduced accumulation of 77-satRNA in infected tissues, and the transition in infected plants from diseased to healthy. Thus, events leading to the degradation of satRNA sequences indicate a role for RNA silencing as the second mechanism determining resistance of transgenic tomato lines.


2011 ◽  
Vol 157 (2) ◽  
pp. 375-377 ◽  
Author(s):  
Shahideh Nouri ◽  
Bryce W. Falk ◽  
Russell L. Groves

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