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. Silencing the hahr3 gene by transgenic plantmediated rnai. Hefferon cornell research foundation, cornell university, ithaca, usa keywords. The protection observed for the transgenic plants as genetically engineered crossprotection. Conclusion virusderived transgenic resistance holds great promise in sparing growers and consumers the costs of losses due to virus infection. In anticipation of a new virus outbreak, scientists at cornell, began a project to develop transgenic virusresistant papaya in 1986. Virus resistant transgenic plants linkedin slideshare. Utilization of engineered resistance to viruses in crops of the.
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. Mechanisms of pathogenderived resistance to viruses in. The industry was full of hope then, but it remained to be seen whether the transgenic papaya would translate this hope to a reality. Transgenic banana plants resistant to banana bunchy top. Genetically modified crops are genetically modified plants that are used in agriculture. Complete document available on olis in its original format. All of the antiviralstrategies used, till to date, were based on protective molecul ar immune mechanisms, evolved naturally in plants against viral diseases. 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.
Hefferon encyclopedia of life support systems eolss plants which possess enhanced nutritional traits. Safety of virusresistant transgenic plants two decades. The genetic diversity of prsv depends upon geographical distribution and the influence of prsv disease management on a sequence of prsv isolates. A prerequisite for the use of pdr is that no interference with essential host functions should occur. Many genes derived from plant rna viruses provided by aphis and by the expressed in transgenic plants confer. Characterized transgenic lines of tomato with a peach acc oxidase promoter and a peach small. 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. Strategies for engineering virus resistance in transgenic.
This discovery led the way for the production of an enormous number of transgenic plants resistant to viruses, using most types of viral genes. Gene technology for papaya ringspot virus disease management. Transgenic strategies to confer resistance against viruses in. This program, still ongoing, has supported numerous studies on risk assessment of virus resistant transgenic plants 5. Utilization of engineered resistance to viruses in crops. Risk assessment of virusresistant transgenic plants annual. Complementation it occurs in transgenic plants if the transgenically expressed protein complements a mutant virus, which is defective in one or more genes. However, resistance genes are not available for all viral diseases of crop plants. Genetic engineering for disease resistance in plants. Biotechnological approaches for plant viruses resistance. Genetically modified maize is a genetically modified crop. In these experi ments, transgenic tobacco plants expressing high levels of the tmv cp were more resistant to tmvvirions than to tmv rna inocula. 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.
New hope for control of papaya ringspot virus in hawaii. Control of plant virus diseases by pathogenderived resistance in transgenic plants karenbeth c. Transgenic crops the methods, pros and cons of gmos and. Safety of virusresistant transgenic plants two decades after. There is no scientific reason to suspect that the nature of the hazard associated with virus recombination i. Pdf genetic engineering for virus resistance researchgate. The transgenic plant providing coat proteinmediated resistance to virus are rice, potato, wheat, tobacco, peanut, sugar beet, alfalfa etc. Maize strains with both traits are now in use in multiple countries. 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. Oct 27, 20 movement proteins rapid spread of virus. No genetic source of bbtv resistance has been reported to date. The second generation of crops aimed to improve the quality, often by altering the nutrient profile. A critical evaluation of whether recombination in virus.
The concept of pathogenderived resistance has been employed for the. Two of the most influential early documents in the recasting of gmo risk. Chapter 6 genetically engineered virus resistant plants in developing countries. First, the virus must be purified and the viral rna or dna isolated. Rnaimediated resistance to cucumber mosaic virus cmv. For an rna virus note that 90% of plant viruses have rna genomes. Develop orchid plants with resistance to cymbidium mosaic virus cymmv. 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. Goals objectives the objectives of this cooperative research project are to. The primary mechanism of virus transmission is by arthropod vectors such as. 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.
Cucumber mosaic virus is one of the most constraints to the production of tomato and other vegetable crops worldwide. In this section, current techniques employed in plant transformation are investigated. Ppt virus resistance mechanisms in plants powerpoint. Prsvresistant papaya effectively saved papaya production hawaii 32, 33. 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. The mechanism of resistance in genetically engineered plants became comprehensible with the discovery of posttranscriptional gene silencing.
Mukherjee department of plant molecular biology, university of delhi south campus, benito juarez road, new delhi 110 021, india. This experiment revealed that these transgenic plants may not be immune to virus infection but they may exhibit partial resistance or tolerance. Small rna based genetic engineering for plant viral resistance. Control of plant virus diseases by pathogenderived. Transgenic virus resistant plants were first produced in 1986 by genetically engineering tobacco plants to express the coat protein of tobacco mosaic virus. Yehui xiong, hongmei zeng, yuliang zhang, dawei xu, dewen qiu. The completely resistant lines were selected and challenged with a closely related strain, cmvy. In conferring such resistance to potato varieties it proved to be possible to preserve their intrinsic properties. A case study of bacillus thuringiensis bt and its transfer to developing countries anatole f. 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. The most successful approach is the viral coat protein mediated resistance cpmr. Assessment of nutritional characteristics of virus resistant transgenic white clover trifolium repens l. Transgenic papayas carrying the papaya ringspot virus coat protein gene were inoculated with papaya ringspot virus.
Papaya carica papaya is severely damaged by the papaya ringspot virus prsv. Biotechnology school of biotechnology davv, indore 2. Ten years experience of the french biomolecular engineering commission 9. Development of transgenic watermelon resistant to cucumber. A critical evaluation of whether recombination in virusa. Among eight tested transgenic lines, clone g2 was found highly resistant to virus infection during 3 years of testing. Whereas, no symptoms were observed in 24 week old transgenic plants inoculated with virus. Genes, genetics and transgenics for virus resistance in plants. Resistance to homologous virus was due to inhibition of viral transcription and replication, while resistance to the heterologous virus tylcv was due to interaction. Evaluate lines of transgenic lettuce and tomato for tomato spotted wilt virus tswv resistance. Extensive field trials with transgenic, virus resistant. 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.
Extensive field trials with transgenic, virus resistant tobacco. 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. We have generated a collection of doubled haploid dh transgenic. Several successful field trials of virus resistant transgenic plants have been carried out. Production of genetically modified plants with improved resistance to viral disease is one of the.
Consultancy report by csiro for environment australia, june 2002. Resistance of transgenic papaya plants to papaya ringspot virus article pdf available in biologia plantarum 512. Jackson department of plant pathology, university of california, berkeley, california 94720 plant viruses have an enormous negative impact on agri. A critical appraisal of non conventional resistance to plant viruses. Six years have transpired since the commercialization of the transgenic. Expression of coat protein in transgenic plants results. Transgenic virus resistant plums poised for release nw. Environmental risks associated with viral recombination in. 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. 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. Approach from ad416 we will work towards developing virusresistant plants, using transgenic plant technology.
Based on this observation, it was suggested that cp. Resistance of transgenic papaya plants to papaya ringspot. Transgenic nicotiana benthamiana resistance to synergistic. The coat protein of the virus was engineered into papaya. Download environmental risks associated with viral. 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. Assessment of nutritional characteristics of virus. 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. No virus could be detected in uninoculated new leaves of.
Transgenic virusresistant plants were first produced in 1986 by genetically engineering tobacco plants to express the coat protein of tobacco mosaic virus. 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. Genetically engineered virusresistant plants in developing. Numerous attempts were then conducted to generate viral resistance in plants through expression of viral proteins from transgene and in several. Zymv and wmv are related to prsv they are all in the same genus, potyvirus and are targeted by. 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. Development of transgenic bananas for bbtv resistance. Subsequently, several different strategies have been attempted for developing virus resistant plants 3,4 and. Key laboratory of integrated pest management in crops, ministry of agriculture. Plants and viruses enter into various relationships that do not necessarily result in damage to the host. Environmental risks associated with viral recombination in virus resistant transgenic plants final report. Pdf safety of virusresistant transgenic plants two decades.
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. Crop losses as a result of virus diseases can be especially serious in developing countries in tropical and subtropical regions. Utilization of engineered resistance to viruses in crops of. Ishs xiv international symposium on virus diseases of ornamental plants transgenic nicotiana benthamiana resistance to synergistic infection of two orchid viruses cymmv and orsv. Therefore, virus resistance engineered in plants using modern biotechnology methods is an important addition to the crop production toolbox.
Success has been achieved in transgenic crops against. Pdf viral, fungal and bacterial disease resistance in. Transgenic banana resistant to banana bunchy top virus. Papaya transformation was greatly facilitated by the recent invention of the gene gun at cornell. Pdf overview of acquired virus resistance in transgenic. 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. Transgenic virus resistant plums poised for release. A selected list of the virus resistant transgenic plants with sources of virus coat protein genes is given in table 50. Hence, healthy planting materials and virus resistant cultivars are essential for high yields of good quality. Rnaimediated resistance to cucumber mosaic virus cmv in. Plant viruses are the potential candidate in affecting crop yield. 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. Pmc free article maiti ib, murphy jf, shaw jg, hunt ag.
Silencing the hahr3 gene by transgenic plant mediated rnai to disrupt helicoverpa armigera development. Participated in a group effort to create a plum pox potyvirus resistant plum tree, honeysweet, through genetic engineering. 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. Develop virus resistant plants using transgenic plant technology. 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. Plant resistance to virus diseases through genetic. The level of protection conferred by cp genes in transgenic plants varies from immunity to delay and attenuation of symptoms. Further characterize any bbtv resistant transgenic banana lines.
Stability of transgenic resistance against plant viruses. Viral, fungal and bacterial disease resistance in transgenic. In this work, we used the coat protein gene of a prsv. A critical evaluation of whether recombination in virusresistant transgenic plants will lead to the emergence of novel viral diseases. Several conventional methods such as breeding for resistance, heat treatment are enforced to combat viral menace. Interestingly, the transgenic plant lines either remained immune or showed high levels of resistance to the strain. Article full text enhanced pdf format, 1169966 bytes article sharing repository deposits.
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. About 10% of world crop production is lost annually because of plant diseases caused by bacteria, fungi and viruses fraser, 1985. Plants that express a potyvirus proteinase gene are resistant to virus. Environmental risks associated with viral recombination in virus. 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. Dual resistance of transgenic plants against cymbidium. If a pathogenic virus succeeds in infecting a plant, a.
Induction of a highly specific antiviral state in transgenic plants. 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. Infection was monitored by evaluating symptoms and by reverse transcription polymerase chain reaction rtpcr. Virus resistant transgenic plants vrtps hold the promise of enormous benefit for agriculture. Baulcombe lhe sainsbury laboratory, john lnnes centre, colney, norwich nr4 7uh, united kingdom. Plant viruses can be serious pathogens in crops as they can cause anywhere from minor losses to total crop failure.
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. Virus resistant transgenic plants for environmentally safe. Posttranscriptional gene silencing is involved in resistance. 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. 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. Posttranscriptional gene silencing is involved in resistance of transgenic papayas to papaya ringspot virus p. Development of viral resistant plants biotechnology notes. However, prsv resistance in the transgenic papaya is rather specific to local. Download environmental risks associated with viral recombination in virus resistant transgenic plants final report pdf viralrecombination.
Establishment of transgenic plants establishment in greenhouse. 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. Transgenic banana resistant to banana bunchy top virus john hu, et al. Provided information for deregulating the transgenic plum. Strategies for engineering virus resistance in transgenic plants. Resistant ff 3 transgenic plants had a higher transgene expression as compared to non resistant plants. Transgenic plants resistant to plant viruses, insects and herbicides are discussed. Stability of transgenic resistance against plant viruses intechopen. Transgenic plants encyclopedia of life support systems. Specific maize strains have been genetically engineered to express agriculturallydesirable traits, including resistance to pests and to herbicides. 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. Stephan neidenbach there are two different transgenic events for virus resistance in summer squash.
Overview of acquired virus resistance in transgenic plants. Current status and future prospects dedicated to the late nobel laureate dr. In this article we will discuss about the viral resistance in transgenic plants. Resistance of transgenic papaya plants to papaya ringspot virus. Pdf potential safety issues have been raised with the development and release of virusresistant transgenic plants. Despite of the success that virusresistant cropping of transgenic plants begins. Virus resistance and gene silencing in plants can be.
Crop plants made virus resistant through coat protein. Biosafety considerations relevant to virusresistant. Advancement in plant transformation techniques enables transferring useful genes for the rational creation of disease resistant plants. The mechanism of papmediated resistance to virus infection was initially thought to be due to inactivation of the 28s rrna. 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. 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. Virus resistance mechanisms in plants is the property of its rightful owner. However, over the past ten years, questions concerning the potential ecological impact of vrtps have been raised. If so, share your ppt presentation slides online with. 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.
Disease control is limited to the control of vector and use of virus free planting material. Institute of plant protection, chinese academy of agricultural sciences, beijing, 81, p. Norman borlaug, father of the green revolution, for ardently supporting biotechnological approaches for increasing crop production and the improvement of crop quality. How virus resistance works in gmos biology fortified inc. 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. Transgenic potato plants resistant to viruses springerlink. Pdf resistance of transgenic papaya plants to papaya.
Implications for regulation of gene expression and virus resistance. In a number of crops, transgenics resistant to an infective. The first, zw20 12, targets zymv and wmv whereas the second, czw3, targets cmv in addition to zymv and wmv. Transgenic banana plants resistant to banana bunchy top virus infection w.