scholarly journals Cucumber mosaic virus Infection Transiently Breaks dsRNA-Induced Transgenic Immunity to Potato virus Y in Tobacco

2003 ◽  
Vol 16 (10) ◽  
pp. 936-944 ◽  
Author(s):  
Neena Mitter ◽  
Emy Sulistyowati ◽  
Ralf G. Dietzgen

Post-transcriptional gene silencing (PTGS), an intrinsic plant defense mechanism, can be efficiently triggered by double stranded (ds)RNA-producing transgenes and can provide high level virus resistance by specific targeting of cognate viral RNA. The discovery of virus-encoded suppressors of PTGS led to concerns about the stability of such resistance. Here, we show that Cucumber mosaic virus (CMV) is able to suppress dsRNA-induced PTGS and the associated Potato virus Y (PVY) immunity in tobacco. CMV suppression supported only a transient PVY accumulation and did not prevent recovery of the transgenic plants from PVY infection. CMV inoculation resulted in strongly increased transgene mRNA levels due to suppression of PTGS, but accumulation of PVY-specific small interfering (si)RNA was unaffected. However, PVY accumulation in previously immune plants resulted in increased PVY siRNA levels and transgene mRNA was no longer detected, despite the presence of CMV. Transgene mRNA returned to high levels once PVY was no longer detected in CMV-infected plants. Recovered and chronically CMV-infected tissues were immune to further PVY infection.

Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 447-447 ◽  
Author(s):  
X. D. Li ◽  
Y. Q. Li ◽  
H. G. Wang

Flue-cured tobacco is an important crop in Henan Province, China. During the 2000 growing season, many tobacco plants showed various degrees of mottling, mosaic, vein clearing, or vein necrosis in most of the counties. Some plants even died at an early stage of growth. A survey was conducted in May-June in several tobacco-growing counties, and the incidence of symptomatic plants in individual fields ranged from 10 to 85%. The most widely planted tobacco varieties, NC89, K326, and K346, were highly susceptible. Symptomatic plants were collected from Jiaxian and Xiangcheng counties and samples were tested by enzyme-linked immunosorbent assay for Tobacco mosaic virus (TMV), Cucumber mosaic virus (CMV), Potato virus Y (PVY), and Potato virus X (PVX). Of 65 samples tested, 21 were positive for only PVY, 16 positive for only CMV, one each was positive for only TMV or PVX. Nineteen samples were doubly infected with various combinations of these viruses and six were infected with combinations of three viruses. The causal agent(s) in the remaining sample could not be determined. In total, CMV was detected in 40 samples, PVY in 38, PVX in 10, and TMV in 7 samples. TMV and CMV used to be the most important viruses and PVY occurred only rarely. But PVY has become prevalent in Henan and in neighboring Shandong province (2). CMV and TMV were reported to be the most prevalent viruses in Shanxi (1) and Fujian Provinces (3). Because resistant varieties are not available, and mixed infections are more common, the results presented here explain why huge damage is occurring in tobacco crops in recent years. Some varieties are partially resistant to TMV and CMV but the varieties commonly grown are highly susceptible to PVY. Therefore, breeding for resistance to viruses, especially to PVY, is urgent to control the occurrence of tobacco viral diseases. References: (1) J. L. Cheng et al. Acta Tabacaria Sin. 4:43, 1998. (2) J. B. Wang et al. Chinese Tobacco Sci. 1:26, 1998. (3) L. H. Xie et al. Acta Tabacaria Sin. 2:25, 1994.


2018 ◽  
Vol 3 (2) ◽  
pp. 381-390
Author(s):  
Rodolfo Velásquez-Valle ◽  
Luis Roberto Reveles-Torres ◽  
Jaime Mena-Covarrubias

A nivel mundial el cultivo de chile es afectado por más de 60 enfermedades virales; sin embargo, poco se conoce acerca de ellas en el área productora de chile seco del norte centro de México por lo que el objetivo del presente trabajo consistió en detectar la presencia y sintomatología de cinco virus en parcelas comerciales de chile seco en los estados mencionados. Plantas de chile de los tipos mirasol y ancho fueron muestreadas y se anotó la presencia de síntomas como enanismo, clorosis, deformación de hojas, defoliación, necrosis vascular y ramas unidas. Las muestras fueron analizadas mediante la técnica DAS- ELISA empleando los antisueros para el virus del mosaico del tabaco (Tobacco mosaic virus: TMV), mosaico del pepino (Cucumber mosaic virus: CMV), Y de la papa (Potato virus Y: PVY), moteado del chile (Pepper mottle virus: PepMoV) y jaspeado del tabaco (Tobacco etch virus: TEV). Esos virus fueron identificados en plantas de chile colectadas en las parcelas comerciales de chile seco de los tres estados antes mencionados.


2008 ◽  
Vol 21 (6) ◽  
pp. 675-684 ◽  
Author(s):  
Marco Morroni ◽  
Jeremy R. Thompson ◽  
Mark Tepfer

Plant genetic engineering has promised researchers improved speed and flexibility with regard to the introduction of new traits into cultivated crops. A variety of approaches have been applied to produce virus-resistant transgenic plants, some of which have proven to be remarkably successful. Studies on transgenic resistance to Cucumber mosaic virus probably have been the most intense of any plant virus. Several effective strategies based on pathogen-derived resistance have been identified; namely, resistance mediated by the viral coat protein, the viral replicase, and post-transcriptional gene silencing. Techniques using non-pathogen-derived resistance strategies, some of which could offer broader resistance, generally have proven to be much less effective. Not only do the results obtained so far provide a useful guide to help focus on future strategies, but they also suggest that there are a number of possible mechanisms involved in conferring these resistances. Further detailed studies on the interplay between viral transgene-derived molecules and their host are needed in order to elucidate the mechanisms of resistance and pathogenicity.


2019 ◽  
Vol 9 (1) ◽  
pp. 151
Author(s):  
Shankar Hemanta Gogoi ◽  
Palash Deb Nath ◽  
Ranima Mishra ◽  
Sheriful Alam

2020 ◽  
Vol 11 ◽  
Author(s):  
Hiroki Atarashi ◽  
Wikum Harshana Jayasinghe ◽  
Joon Kwon ◽  
Hangil Kim ◽  
Yosuke Taninaka ◽  
...  

Eukaryotic translation initiation factors, including eIF4E, are susceptibility factors for viral infection in host plants. Mutation and double-stranded RNA-mediated silencing of tomato eIF4E genes can confer resistance to viruses, particularly members of the Potyvirus genus. Here, we artificially mutated the eIF4E1 gene on chromosome 3 of a commercial cultivar of tomato (Solanum lycopersicum L.) by using CRISPR/Cas9. We obtained three alleles, comprising two deletions of three and nine nucleotides (3DEL and 9DEL) and a single nucleotide insertion (1INS), near regions that encode amino acid residues important for binding to the mRNA 5' cap structure and to eIF4G. Plants homozygous for these alleles were termed 3DEL, 9DEL, and 1INS plants, respectively. In accordance with previous studies, inoculation tests with potato virus Y (PVY; type member of the genus Potyvirus) yielded a significant reduction in susceptibility to the N strain (PVYN), but not to the ordinary strain (PVYO), in 1INS plants. 9DEL among three artificial alleles had a deleterious effect on infection by cucumber mosaic virus (CMV, type member of the genus Cucumovirus). When CMV was mechanically inoculated into tomato plants and viral coat accumulation was measured in the non-inoculated upper leaves, the level of viral coat protein was significantly lower in the 9DEL plants than in the parental cultivar. Tissue blotting of microperforated inoculated leaves of the 9DEL plants revealed significantly fewer infection foci compared with those of the parental cultivar, suggesting that 9DEL negatively affects the initial steps of infection with CMV in a mechanically inoculated leaf. In laboratory tests, viral aphid transmission from an infected susceptible plant to 9DEL plants was reduced compared with the parental control. Although many pathogen resistance genes have been discovered in tomato and its wild relatives, no CMV resistance genes have been used in practice. RNA silencing of eIF4E expression has previously been reported to not affect susceptibility to CMV in tomato. Our findings suggest that artificial gene editing can introduce additional resistance to that achieved with mutagenesis breeding, and that edited eIF4E alleles confer an alternative way to manage CMV in tomato fields.


2006 ◽  
Vol 23 (3) ◽  
pp. 259-265 ◽  
Author(s):  
Shungo Otagaki ◽  
Makoto Arai ◽  
Akiko Takahashi ◽  
Kazunori Goto ◽  
Jin-Sung Hong ◽  
...  

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