Two of the most influential early documents in the recasting of gmo risk. Several successful field trials of virus resistant transgenic plants have been carried out. Hefferon encyclopedia of life support systems eolss plants which possess enhanced nutritional traits. Six years have transpired since the commercialization of the transgenic.
The second generation of crops aimed to improve the quality, often by altering the nutrient profile. A critical appraisal of non conventional resistance to plant viruses. Resistant ff 3 transgenic plants had a higher transgene expression as compared to non resistant plants. Genes, genetics and transgenics for virus resistance in plants. Dual resistance of transgenic plants against cymbidium. No virus could be detected in uninoculated new leaves of. All the transgenic plants with the introduced rnai trigger constructs for pc5 and pc6 were asymptomatic at 4 weeks postinoculation, in contrast to the typical severe stunting of plant growth with profuse tillering of all infected non transgenic plants, and they continued to be symptomfree and with no detectable amounts of the virus until. Plants that express a potyvirus proteinase gene are resistant to virus. Subsequently, several different strategies have been attempted for developing virus resistant plants 3,4 and. Yehui xiong, hongmei zeng, yuliang zhang, dawei xu, dewen qiu.
Based on this observation, it was suggested that cp. The coat protein of the virus was engineered into papaya. A case study of bacillus thuringiensis bt and its transfer to developing countries anatole f. In conferring such resistance to potato varieties it proved to be possible to preserve their intrinsic properties. Crop plants made virus resistant through coat protein. Extensive field trials with transgenic, virus resistant tobacco. Transgenic virus resistant plants were first produced in 1986 by genetically engineering tobacco plants to express the coat protein of tobacco mosaic virus. A critical evaluation of whether recombination in virusresistant transgenic plants will lead to the emergence of novel viral diseases. Environmental risks associated with viral recombination in. Although several transgenic cucurbits with multiviral resistance have been reported, such as squash, cantaloupe and oriental melon, there were few reports of transgenic watermelon with virus resistance. Papaya transformation was greatly facilitated by the recent invention of the gene gun at cornell.
This experiment revealed that these transgenic plants may not be immune to virus infection but they may exhibit partial resistance or tolerance. The first, zw20 12, targets zymv and wmv whereas the second, czw3, targets cmv in addition to zymv and wmv. Resistance to homologous virus was due to inhibition of viral transcription and replication, while resistance to the heterologous virus tylcv was due to interaction. Researchers have long observed that transgenic plants expressing genes derived from viral pathogens often display immunity to the pathogen and its related strains lomonossoff, 1995. Overview of acquired virus resistance in transgenic plants. Consultancy report by csiro for environment australia, june 2002. Therefore, virus resistance engineered in plants using modern biotechnology methods is an important addition to the crop production toolbox. The level of protection conferred by cp genes in transgenic plants varies from immunity to delay and attenuation of symptoms. Pdf overview of acquired virus resistance in transgenic. The transgenic plant carrying a virus derived sequence presents an increase in risk compared to the non transgenic plant only if the frequency with which viable recombinants are generated in the former is significantly greater. Develop virus resistant plants using transgenic plant technology.
Hence, healthy planting materials and virus resistant cultivars are essential for high yields of good quality. Numerous attempts were then conducted to generate viral resistance in plants through expression of viral proteins from transgene and in several. Plants and viruses enter into various relationships that do not necessarily result in damage to the host. Production of genetically modified plants with improved resistance to viral disease is one of the. Complete document available on olis in its original format. In these experi ments, transgenic tobacco plants expressing high levels of the tmv cp were more resistant to tmvvirions than to tmv rna inocula. Biotechnological approaches for plant viruses resistance. Transgenic virus resistant plums poised for release. Zaitlin and hull, 1987, the isolated viral rna is used as a template for reverse transcriptase to produce a cdna copy of the viral genome.
In a number of crops, transgenics resistant to an infective. Viral, fungal and bacterial disease resistance in transgenic. Genetically engineered virusresistant plants in developing. Virus resistant transgenic plants vrtps, developed by the transfer of transgenes from virus, plant or other origins, have been found resistant to a wide range of viruses. Genetic engineering for disease resistance in plants. Several studies have also indicated that non transgenic plants grafted onto resistant transgenic lines could result in transfer of resistance to scions, such as with prunus necrotic ringspot virus.
Transgenic papayas carrying the papaya ringspot virus coat protein gene were inoculated with papaya ringspot virus. About 10% of world crop production is lost annually because of plant diseases caused by bacteria, fungi and viruses fraser, 1985. The most successful approach is the viral coat protein mediated resistance cpmr. Stability of transgenic resistance against plant viruses. Evaluate lines of transgenic lettuce and tomato for tomato spotted wilt virus tswv resistance. Transgenic resistance to plant viruses is an important technology for control of plant virus infection, which has been demonstrated for many model systems, as well as for the most important plant.
However, planting into areas where endemic virus diseases occur and mixed virus infections are expected especially during early stages of the vegetation period, time intervals of low air temperature and greenhouse or open field cultivation practices could affect the stability of transgenic resistance against plant. This is the first report of the development of transgenic plants with double resistance to the two most prevailing viruses, cymmv and orsv, that infect orchids. Extensive field trials with transgenic, virus resistant. Disease control is limited to the control of vector and use of virus free planting material.
If so, share your ppt presentation slides online with. Virus resistant transgenic plants for environmentally safe. For nonexpressing viral sequences, the mechanism of disease resistance appears to have arisen as part of an adaptive defence strategy against invading viruses through sequence specific enzymatic degradation. Induction of a highly specific antiviral state in transgenic plants. Zymv and wmv are related to prsv they are all in the same genus, potyvirus and are targeted by. In transgenic plants, this kind of rnamediated resistance is usually a result of transgene rearrangement leading to inverted repeats of transgene, which have been shown to be the inducers of ptgs and virus resistance smith et al. Pdf safety of virusresistant transgenic plants two decades. Strategies for engineering virus resistance in transgenic plants. This discovery led the way for the production of an enormous number of transgenic plants resistant to viruses, using most types of viral genes. Thus, the cp gene of potato mosaic virus pmv strain n605 provides resistance in transgenic potato plants against this virus strain and also to the related strain.
A critical evaluation of whether recombination in virus. Plant virology protocols offers for the first time a comprehensive collection of stateoftheart techniques for generating transgenic plants that are resistant to plant viruses via the cloning and expression of the coat protein gene. Approach from ad416 we will work towards developing virusresistant plants, using transgenic plant technology. Stephan neidenbach there are two different transgenic events for virus resistance in summer squash. Download environmental risks associated with viral. Oct 27, 20 movement proteins rapid spread of virus. Crop losses as a result of virus diseases can be especially serious in developing countries in tropical and subtropical regions. A prerequisite for the use of pdr is that no interference with essential host functions should occur. The first crops provided are used for animal or human food and provide resistance to certain pests, diseases, environmental conditions, spoilage or chemical treatments e. Prsvresistant papaya was one of the first virusresistant transgenic plants approved in 1998, and was for a long time the only transgenic crop developed entirely with public funding. Resistant ff 3 transgenic plants had a higher transgene expression as compared to non resistant plants, coupled with the absence of cymmv and orsv coat protein which suggests negligible cymmv and orsv concentration in that resistant plant which allowed the plant to exhibit a normal phenotype after mixed inoculation for three weeks. Biotechnology school of biotechnology davv, indore 2. Many genes derived from plant rna viruses provided by aphis and by the expressed in transgenic plants confer.
However, a deletion mutant of pap in the cterminal domain of 28s rrna that lacked depurination ability still exhibited virus resistance in transgenic plants tumer et al. Current status and future prospects dedicated to the late nobel laureate dr. However, planting into areas where endemic virus diseases occur and mixed virus infections are expected especially during early stages of the vegetation period, time intervals of low air temperature and greenhouse or open field cultivation practices could affect the stability of transgenic resistance against plant viruses. Advancement in plant transformation techniques enables transferring useful genes for the rational creation of disease resistant plants. There is no scientific reason to suspect that the nature of the hazard associated with virus recombination i. Rnaimediated resistance to cucumber mosaic virus cmv. Specific features of virus infection make it possible to interfere with different steps of the infection and disease cycle by accumulating products of chimeric genes introduced into transgenic plants. Plant viruses can be serious pathogens in crops as they can cause anywhere from minor losses to total crop failure. About 300 transformed plants were produced these were screened for bbtv resistance in bioassays using aphid inoculations 100% of nontransformed control plants developed symptoms within 34 weeks 7 transformed plants did not develop bbtv symptoms for one year after inoculation butall 7 eventually developed symptoms. However, prsv resistance in the transgenic papaya is rather specific to local.
Specific maize strains have been genetically engineered to express agriculturallydesirable traits, including resistance to pests and to herbicides. Biosafety considerations relevant to virusresistant. Resistance of transgenic papaya plants to papaya ringspot virus. Utilization of engineered resistance to viruses in crops of. Conclusion virusderived transgenic resistance holds great promise in sparing growers and consumers the costs of losses due to virus infection.
Transgenic plants encyclopedia of life support systems. Institute of plant protection, chinese academy of agricultural sciences, beijing, 81, p. In this article we will discuss about the viral resistance in transgenic plants. Pmc free article maiti ib, murphy jf, shaw jg, hunt ag. A critical evaluation of whether recombination in virusa. However, resistance genes are not available for all viral diseases of crop plants. Silencing the hahr3 gene by transgenic plant mediated rnai to disrupt helicoverpa armigera development. Prsvresistant papaya effectively saved papaya production hawaii 32, 33. Goals objectives the objectives of this cooperative research project are to. In this section, current techniques employed in plant transformation are investigated. Establishment of transgenic plants establishment in greenhouse. Implications for regulation of gene expression and virus resistance. Utilization of engineered resistance to viruses in crops of the. Transgenic virusresistant plants were first produced in 1986 by genetically engineering tobacco plants to express the coat protein of tobacco mosaic virus.
Download environmental risks associated with viral recombination in virus resistant transgenic plants final report pdf viralrecombination. Article full text enhanced pdf format, 1169966 bytes article sharing repository deposits. Transgenic plants of papaya cultivar sunset containing the coat protein gene of the mild strain ha 51 of prsv showed resistance to the severe strain. Ppt virus resistance mechanisms in plants powerpoint. Maize strains with both traits are now in use in multiple countries. On 9 september 2004 the agricultural research service of the united states department of agriculture usda petitioned that virus resistant transgenic plums be given nonregulated status. Resistance of transgenic papaya plants to papaya ringspot.
Gm maize has also caused controversy with respect to possible health effects, impact on other insects and impact on other. Historically, expression of the coat protein gene of tobacco mosaic virus in transgenic tobacco nicotiana tabacum plants is the first example of transgenemediated resistance to a plant virus. Transgenic banana resistant to banana bunchy top virus john hu, et al. Chapter 6 genetically engineered virus resistant plants in developing countries. Further characterize any bbtv resistant transgenic banana lines. A selected list of the virus resistant transgenic plants with sources of virus coat protein genes is given in table 50. Success has been achieved in transgenic crops against. Interestingly, the transgenic plant lines either remained immune or showed high levels of resistance to the strain.
Participated in a group effort to create a plum pox potyvirus resistant plum tree, honeysweet, through genetic engineering. If a pathogenic virus succeeds in infecting a plant, a. Virus resistant transgenic plants vrtps hold the promise of enormous benefit for agriculture. The industry was full of hope then, but it remained to be seen whether the transgenic papaya would translate this hope to a reality. Posttranscriptional gene silencing is involved in resistance of transgenic papayas to papaya ringspot virus p. In some cases, detailed study of the mode of action of the resistance gene has made it possible to eliminate the source of potential risk, notably the possible effects of heterologous. Resistance of transgenic papaya plants to papaya ringspot virus article pdf available in biologia plantarum 512. Several conventional methods such as breeding for resistance, heat treatment are enforced to combat viral menace. Utilization of engineered resistance to viruses in crops. Safety of virusresistant transgenic plants two decades. Transgenic nicotiana benthamiana resistance to synergistic. Mechanisms of pathogenderived resistance to viruses in.
However, over the past ten years, questions concerning the potential ecological impact of vrtps have been raised. Development of viral resistant plants biotechnology notes. Environmental risks associated with viral recombination in virus. The genetic diversity of prsv depends upon geographical distribution and the influence of prsv disease management on a sequence of prsv isolates. Transgenic banana plants resistant to banana bunchy top. The protection observed for the transgenic plants as genetically engineered crossprotection. Assessment of nutritional characteristics of virus resistant transgenic white clover trifolium repens l. Risk assessment of virusresistant transgenic plants annual. Strategies for engineering virus resistance in transgenic. Papaya carica papaya is severely damaged by the papaya ringspot virus prsv. Transgenic strategies to confer resistance against viruses in. Silencing the hahr3 gene by transgenic plantmediated rnai.
Pdf viral, fungal and bacterial disease resistance in. Transgenic plants resistant to plant viruses, insects and herbicides are discussed. Assessment of nutritional characteristics of virus. Ten years experience of the french biomolecular engineering commission 9. First, the virus must be purified and the viral rna or dna isolated.
Protection against tobacco mosaic virus tmv infection in transgenic plants that express chimeric gene containing cdna of the coat protein gene of tobacco mosaic virus has been described. Virus resistance and gene silencing in plants can be. Develop orchid plants with resistance to cymbidium mosaic virus cymmv. Small rna based genetic engineering for plant viral resistance. Control of plant virus diseases by pathogenderived. Development of transgenic watermelon resistant to cucumber. Key laboratory of integrated pest management in crops, ministry of agriculture. The mechanism of resistance in genetically engineered plants became comprehensible with the discovery of posttranscriptional gene silencing. This program, still ongoing, has supported numerous studies on risk assessment of virus resistant transgenic plants 5. Mukherjee department of plant molecular biology, university of delhi south campus, benito juarez road, new delhi 110 021, india. Transgenic crops the methods, pros and cons of gmos and. Pdf potential safety issues have been raised with the development and release of virusresistant transgenic plants. Baulcombe lhe sainsbury laboratory, john lnnes centre, colney, norwich nr4 7uh, united kingdom. Rnaimediated resistance to cucumber mosaic virus cmv in.
The majority of virus resistant transgenic plants can be considered to be the result of pathogenderived resistance pdr brought about the expression of viral sequences in plant cells leading to plant protection prins et al, 2008. Virus resistance mechanisms in plants is the property of its rightful owner. All of the antiviralstrategies used, till to date, were based on protective molecul ar immune mechanisms, evolved naturally in plants against viral diseases. No genetic source of bbtv resistance has been reported to date. In anticipation of a new virus outbreak, scientists at cornell, began a project to develop transgenic virusresistant papaya in 1986. The introduction of coat protein transgenes has since proved to be an extremely effective and generally applicable approach to engineering virus resistance in crop plants. Control of plant virus diseases by pathogenderived resistance in transgenic plants karenbeth c. Plant resistance to virus diseases through genetic. Safety of virusresistant transgenic plants two decades after. Here, we generated an rnai construct containing inverted repeat of 18 bp fragment of a partial replicase gene of cmvo and used it to produce transgenic tomato plants expressing cmvspecific dsrna of the replicase gene.
Stability of transgenic resistance against plant viruses intechopen. Pdf resistance of transgenic papaya plants to papaya. For virus resistance the gene for the coat protein of a given virus transplanted into the genome of the plant renders the plant resistant to that virus. Environmental risks associated with viral recombination in virus resistant transgenic plants final report. For an rna virus note that 90% of plant viruses have rna genomes. Pdf genetic engineering for virus resistance researchgate. Gene technology for papaya ringspot virus disease management. The mechanism of papmediated resistance to virus infection was initially thought to be due to inactivation of the 28s rrna. Characterized transgenic lines of tomato with a peach acc oxidase promoter and a peach small. New hope for control of papaya ringspot virus in hawaii. Plant viruses are the potential candidate in affecting crop yield. Banana bunchy top virus bbtv is one of the major viral diseases in banana and affects banana growing areas in all parts of the world.
Transgenic virus resistance plants and new plant viruses many genes derived from plant rna viruses provided by aphis and by the expressed in transgenic plants confer biotechnology industry organization. Transgenic banana plants resistant to banana bunchy top virus infection w. The completely resistant lines were selected and challenged with a closely related strain, cmvy. Posttranscriptional gene silencing is involved in resistance. The expression of virus derived sense or antisense rna in transgenic plants conferring rnamediated virus resistance appears to induce a form of posttranscriptional gene silencing ptgs 4, 5.
Despite of the success that virusresistant cropping of transgenic plants begins. Transgenic potato plants resistant to viruses springerlink. The transgenic plant providing coat proteinmediated resistance to virus are rice, potato, wheat, tobacco, peanut, sugar beet, alfalfa etc. Provided information for deregulating the transgenic plum. How virus resistance works in gmos biology fortified inc. Expression of coat protein in transgenic plants results. The primary mechanism of virus transmission is by arthropod vectors such as. Jackson department of plant pathology, university of california, berkeley, california 94720 plant viruses have an enormous negative impact on agri. Among eight tested transgenic lines, clone g2 was found highly resistant to virus infection during 3 years of testing.
Cucumber mosaic virus is one of the most constraints to the production of tomato and other vegetable crops worldwide. These results led to the hypothesis that ectopic expression of genes encoding wildtype or mutant viral proteins could interfere with the viral life cycle sanford and. Transgenic virus resistant plums poised for release nw. Complementation it occurs in transgenic plants if the transgenically expressed protein complements a mutant virus, which is defective in one or more genes. We have generated a collection of doubled haploid dh transgenic. Hefferon cornell research foundation, cornell university, ithaca, usa keywords. Genetically modified crops are genetically modified plants that are used in agriculture. Transgenic banana resistant to banana bunchy top virus. Norman borlaug, father of the green revolution, for ardently supporting biotechnological approaches for increasing crop production and the improvement of crop quality.
The concept of pathogenderived resistance has been employed for the. The transgenic plant carrying a virus derived sequence presents an increase in risk compared to the non transgenic plant only if the frequency with which. Development of transgenic bananas for bbtv resistance. Whereas, no symptoms were observed in 24 week old transgenic plants inoculated with virus. Infection was monitored by evaluating symptoms and by reverse transcription polymerase chain reaction rtpcr. Genetically modified maize is a genetically modified crop. Ishs xiv international symposium on virus diseases of ornamental plants transgenic nicotiana benthamiana resistance to synergistic infection of two orchid viruses cymmv and orsv. In this work, we used the coat protein gene of a prsv.
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