共查询到20条相似文献，搜索用时 15 毫秒
1.
M. Cambra D. Boscia A. Myrta L. Palkovics M. Navrátil M. Barba M. T. Gorris N. Capote 《EPPO Bulletin》2006,36(2):254-261
Tremendous progress has been made in the research and development of Plum pox virus (PPV) serological reagents and methods in recent years. Two facts have revolutionised the serological detection and characterization of the virus: the development of the ELISA method in 1977, and the later emergence of specific monoclonal antibody technology. The availability of commercial kits has popularised PPV diagnosis, now making diagnosis possible at large scale for quarantine purposes, eradication programmes and control of the disease in nurseries. The use of the universal monoclonal antibody 5B-IVIA, used in DASI-ELISA, is the most accurate system for routine PPV detection. Likewise, the use of typing monoclonal antibodies gives exact characterization of the main PPV types described: 4DG5 for PPV-D, AL for PPV-M, EA24 for PPV-EA, and TUV and AC for PPV-C. There is, in general, an excellent correlation between serological data obtained with PPV specific monoclonal antibodies and data obtained by molecular PCR based methods. ELISA using a single or a mixture of monoclonal antibodies will remain the preferred method for universal detection and routine screening of PPV for years to come. Today, other serological methods and reagents are also recommended in the EPPO Diagnostic Protocol, increasing the number of reliable tests available for PPV detection. These developments have helped to control sharka disease in recent years. International co-operation in this field has been crucial to the improvement and validation of serological tools for PPV detection and characterization. 相似文献
2.
3.
Plum pox virus (PPV) belongs to the genus Potyvirus that contains the largest number of virus species infecting plants. Its virus genome has been extensively characterised and sequenced. However, few data are available on its interactions with woody host plants. We therefore focused, in the past 4 years, both on the cellular and molecular aspects of the compatible and incompatible Prunus /PPV interactions. GFP (Green fluorescent protein)-tagged PPV and in situ hybridisation were used to compare the localization of viral particles in stems and leaves of susceptible and resistant apricot cultivars. In parallel, molecular tools were developed through the cloning and characterization of polymorphic, homologous resistance genes and of candidate genes involved in the expression of Prunus /PPV interactions. Candidate genes are currently used to target genomic regions involved in resistance or susceptibility and to identify molecular markers indispensable for further marker assisted selection for resistance to sharka disease. 相似文献
4.
M. RAVELONANDRO R. SCORZA A. CALLAHAN J. CORDTS M. MONSION M. FUCHS R. DELBOS J. BACHELIER D. GONSALVES J. DUNEZ 《EPPO Bulletin》1994,24(3):713-719
Leaf discs of Nicotiana benthamiana plants were transformed with Agrobacterium tumefaciens and transgenic plants expressing plum pox potyvirus (PPV) coat protein (CP) were generated. Homozygous R2 progeny from these plants were inoculated with PPV. Plants were scored for the appearance of symptoms and tested for infection by DAS-ELISA. Various levels of resistance were obtained after an initial stage in which PPV was able to multiply in all the transgenic plants. Within 2–3 weeks after inoculation, the transgenic resistant plants fully recovered from virus infection. Conversely, control and susceptible transgenic lines developed severe symptoms and high virus titres. Prunus domestica (plum) was transformed by inoculating hypocotyl slices with A. tumefaciens containing a binary plasmid which included the NPTII, GUS, and PPV CP genes within its T-DNA region. Transgenic shoots were rooted and established in the glasshouse. Analysis of selected transformants by PCR showed that the engineered foreign genes had been integrated, including that for PPV CP. Histological assays on young leaves of these putative transformants gave a positive reaction. This suggests that all genes transferred are expressed in these transformed plums. 相似文献
5.
6.
The susceptibility of 115 apricot cultivars to plum pox potyvirus (PPV) has been examined, since 1981, in the experimental plots of the Pomology Institute at Naoussa and Skydra, Makedonia (GR). Inoculation was assured by aphids, transmitting strain PPV-M (Marcus) from naturally infected trees in adjacent peach orchards. For each cultivar, four to six trees were examined for at least 4 years. Observations on symptoms were made on leaves early in May and on fruits at maturity. Most cultivars expressed severe disease symptoms. Those without symptoms were inoculated by grafting onto heavily infected old apricot trees. The grafted shoots were tested for PPV in the following year by ELISA and on the woody indicator GF305. The cultivars which were rated as resistant after artificial inoculation and ELISA came from North America: Early Orange, Stella, NJA2, Sunglo, Veecot, Harlayne, Goldrich and Henderson. Most of these have been crossed with quality cultivars for the creation of resistant hybrids. The PPV resistance of large numbers of these apricot hybrids is now under investigation. 相似文献
7.
8.
John A Lucas 《Pest management science》1999,55(2):193-196
The idea that plants might be able to develop a form of acquired immunity to infection following exposure to a pathogen has been current ever since discovery of the animal immune system in the later years of the nineteenth century. Early attempts to demonstrate a comparable system in plants focused on the detection of precipitating antibodies and hence were doomed to failure. Nevertheless, largely anecdotal evidence for plant immunisation continued to accumulate, culminating in the discovery of phytoalexins in the 1940s. Convincing evidence for systemic changes in plant resistance following an inducer inoculation was not available until 20 years later, when pioneering work on tobacco infected with blue mould (Peronospora tabacina) or tobacco mosaic virus (TMV) showed that tissues remote from the inoculation site were altered in disease reaction type. Increased resistance was expressed as a reduction in lesion numbers and size, and a reduced rate of pathogen reproduction. Systemic acquired resistance (SAR) has now been demonstrated in at least 20 plant species in at least six plant families, although detailed genetic or molecular analysis has mainly been confined to a few models, such as tobacco, cucumber and Arabidopsis. SAR is associated with the coordinate induction of genes encoding defence proteins which can be used as molecular markers of the response. The availability of Arabidopsis mutants altered in the induction and expression of SAR is now providing new insights into the signal transduction pathway(s) involved, and will enable comparison with the molecular mechanisms operating in other plant taxa. Important unresolved questions concern the nature of the translocated signal, the mechanism of defence ‘priming’, efficacy of the response against different pathogens, and practical exploitation of SAR in crop protection. The first generation of chemical plant defence activators is now commercially available and optimal use of these SAR inducers in integrated disease control requires further evaluation. The prospects for engineering transgenic crops altered in the regulation or expression of SAR is also a subject for further investigation. © 1999 Society of Chemical Industry 相似文献
9.
G. Li H. Lv S. Zhang S. Zhang F. Li H. Zhang W. Qian Z. Fang R. Sun 《Plant pathology》2019,68(6):1035-1044
Turnip mosaic virus (TuMV), the only potyvirus known to infect brassicas, is a devastating virus threatening many economically important brassica crops, including cabbage, Chinese cabbage, oilseed rape and mustard. TuMV disease, which was first discovered in the United States, is now found worldwide, especially in Europe, Asia and North America. TuMV results in a yield loss of up to 70% and has a wide host range, infecting most cruciferous plants, as well as many non-cruciferous species. This virus is also characterized by high pathotype diversity because of its highly variable genome structure and has been divided into 12 pathotypes. These characteristics, as well as its nonpersistent transmission mode by as many as 89 aphid species, mean the disease is difficult to prevent through traditional methods such as the application of chemicals, prompting researchers to seek host resistance for effective control. During the last decade, extensive studies have been conducted to investigate inheritance, mapping and cloning of the TuMV resistance genes, and several NB-LRR- or eIF-encoding loci with divergent molecular mechanisms have been uncovered. These studies have greatly facilitated resistance breeding for brassica crops and have advanced our understanding of virus−host interactions. 相似文献
10.
11.
A rapid, simple method for preparing plant tissue infected with plum pox potyvirus (PPV) using a commercial product known as Gene Releaser is described. The Gene Releaser polymeric matrix method produces plant extracts suitable for PCR amplification without the use of organic solvents, ethanol precipitation, or additional nucleic acid purification techniques. We also describe the development of a PPV-specific amplification assay based on the unique 220 nucleotides present in the 3’non-coding region of the PPV genome. This paper demonstrates the simplicity of the Gene Releaser method combined with the accuracy of the PCR assay for the detection of multiple PPV strains from Spain, France, Greece, Italy, Germany, Egypt, Hungary, and Romania. Amplification of the 3’non-coding region of potato Y potyvirus (PVY) using primers for the 3’non-coding region of the PVY genome was also possible with Gene Releaser preparation of viruliferous Myzus persicae to demonstrate the potential usefulness of this work for PPV detection from aphids. 相似文献
12.
For many years, Plum pox virus (PPV) was considered to be transmissible by seed, increasing the fear of long-distance spread of the disease. In the late 1970s, it was claimed on the basis of biological transmission of the virus to herbaceous indicator plants and the development of serological diagnosis based on polyclonal antibodies, that PPV was seed-transmitted, with a different infection rate according to the plant species and part of the seed which was tested. In the 1990s, PPV was characterized into four different types, and specific monoclonal antibodies were produced for them. These new and more sensitive diagnostic techniques, together with RT-PCR with different sets of specific primers, were used to approach once again the problem of PPV transmission through seeds. The virus was detected in seed coats and cotyledons, but embryonic tissue and seedlings obtained from germinated seeds never showed symptoms, and gave negative results for PPV with both ELISA and PCR assays. No PPV isolate is currently recognized to be seed transmitted, so vertical transmission of PPV from infected mother plants to their progeny does not occur. Hypothetically, the only possibility of seed transmission would arise from a mutation in the helper component of the virus, associated with high susceptibility of the infected Prunus cultivar. 相似文献
13.
P. K. Gupta R. Chand N. K. Vasistha S. P. Pandey U. Kumar V. K. Mishra A. K. Joshi 《Plant pathology》2018,67(3):508-531
The spot blotch disease of wheat is caused by Bipolaris sorokiniana, which is an anamorph (teleomorph Cochliobolus sativus). The disease mainly occurs in warm, humid wheat‐growing regions, and the Eastern Gangetic Plains (EGP) of South Asia is a hotspot. Significant progress has been made in recent years in characterizing the host–pathogen interaction. The study of the pathogen's life cycle and diversity have been an active area of research. A number of resistance sources have also been identified, characterized and used for breeding. Although immunity has not been observed in any genotype, cultivars displaying a relatively high level of resistance have been developed and made available to farmers. Further progress will require regular use of marker‐assisted breeding, genomic selection, gene editing and transgenic interventions. This review summarizes the current state of knowledge about genetic and breeding efforts on the wheat–B. sorokiniana pathosystem and discusses ways in which emerging tools can be used for future research to understand the mechanism involved in infection and for developing cultivars exhibiting a high level of resistance. 相似文献
14.
P. Wasswa B. Otto M. N. Maruthi S. B. Mukasa W. Monger R. W. Gibson 《Plant pathology》2011,60(6):1030-1039
Sweet potato begomoviruses diverge basally from all other begomoviruses and have been named sweepoviruses. In 2009, a sweepovirus was detected for the first time in sweet potato crops in Uganda by using the indicator plant Ipomoea setosa and generic primers in a polymerase chain reaction (PCR). An isolate was cloned and sequenced, the first fully sequenced genome of a sweepovirus from mainland Africa. At the nucleotide level, this isolate differed from other sweepoviruses by at least 13%, discriminating the Ugandan isolate as a new species which has been tentatively named Sweet potato leaf curl Uganda virus (SPLCUV). In infected sweet potato plants, SPLCUV showed an uneven distribution; it was detected more often in samples from the midrib and lamina of middle and lower leaves, and reversion to healthy tissue occurred, especially in shoots of cv. New Kawogo. This appears to be the first report of resistance to a sweepovirus in sweet potato. While it was only detected at relatively low efficiency by PCR, use of I. setosa plants as an indicator of sweepovirus infection in sweet potato plants was as efficient as using real‐time quantitative PCR (qPCR). Storage of dry leaves for 84 days and dried DNA extracts for 21 days did not affect the ability of PCR and qPCR to detect it. Sweepovirus(es) was detected frequently using generic primers in cultivars Ejumula, New Kawogo and 318L in eastern and central Uganda. 相似文献
15.
Rafal Baranski Evelyn Klocke Thomas Nothnagel 《Physiological and Molecular Plant Pathology》2007,71(1-3):88-95
Microbial factor 3 (MF3) gene from a plant-growth promoting rhizobacteria Pseudomonas fluorescence was introduced into carrot genome using Agrobacterium-mediated transformation. The obtained transgenic plants expressing MF3 protein were grown in a glasshouse and evaluated for their resistance to phytopathogens. The assays were performed by the assessment of disease symptoms developing on the detached leaflets and petioles inoculated by three fungal pathogens. The results showed that transgenic plants had significantly enhanced resistance to Alternaria dauci, Alternaria radicina and Botrytis cinerea, on average, by 20–40% in comparison to the non-transformed control plants. This is the first report of enhancing plant resistance by expressing the bacterial protein homologous to the family of FK506-binding proteins. 相似文献
16.
Our understanding of the molecular biology of Plum pox virus (PPV) and of the interactions between the virus and its hosts has advanced notably in recent years. Complete genome sequences have been obtained showing up the existence of new subgroups. Functions related to replication, symptom induction, virus movement, and interference with host defense mechanisms have been assigned to the different protein products derived from the proteolytic processing of PPV polyprotein. Moreover, the use of new approaches to define protein–protein interactions between the different viral proteins and between these and the host proteins has begun to yield the first results improving our understanding of how the virus and its host interact during infection. 相似文献
17.
18.
Bean rust, caused by Uramyces appendiculatus, is one of the major diseases in dry and snap bean production world-wide. Numerous advancements in disease management have been made to reduce rust losses. Host resistance is an important component of rust management. However, durability of disease resistance has often been short due to the use of single genes for resistance interacting with extremely high virulence diversity of the bean rust fungus. The challenge to increase durability of resistance has led to strategies such as gene pyramiding of race-specific resistance, selection and use of partial resistance, and investigation and discovery of leaf morphological features that may slow the rust epidemic. Germplasm with multiple sources of rust resistance has been developed in specific bean seed classes and released for public and commercial use in intensive production systems such as those in the United States. However, progress to develop rust resistant germplasm for the subsistence agriculture of Latin America and Africa where intercropping and mixed cultivars dominate the production system has been slow. Incorporation of high yielding, disease-resistant components as partial replacement in farmer's mixtures has the potential to reduce severity in the crop and increase yield in the presence of rust. This strategy would not erode the genetic diversity that is historically known to enhance resistance durability and for many years has given stability in production in the subsistent agriculture systems. 相似文献
19.
Priming: it’s all the world to induced disease resistance 总被引：2，自引：0，他引：2
Katharina Goellner Uwe Conrath 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(3):233-242
After infection by a necrotising pathogen, colonisation of the roots with certain beneficial microbes, or after treatment
with various chemicals, many plants establish a unique physiological situation that is called the ‘primed’ state of the plant.
In the primed condition, plants are able to ‘recall’ the previous infection, root colonisation or chemical treatment. As a
consequence, primed plants respond more rapidly and/or effectively when re-exposed to biotic or abiotic stress, a feature
that is frequently associated with enhanced disease resistance. Though priming has been known as a component of induced resistance
for a long time, most progress in the understanding of the phenomenon has been made over the past few years. Here we summarize
the current knowledge of priming and its relevance for plant protection in the field. 相似文献
20.
Molecular approaches for characterization and use of natural disease resistance in wheat 总被引：3，自引：0，他引：3
Navreet Kaur Kenneth Street Michael Mackay Nabila Yahiaoui Beat Keller 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(3):387-397
Wheat production is threatened by a constantly changing population of pathogen species and races. Given the rapid ability
of many pathogens to overcome genetic resistance, the identification and practical implementation of new sources of resistance
is essential. Landraces and wild relatives of wheat have played an important role as genetic resources for the improvement
of disease resistance. The use of molecular approaches, particularly molecular markers, has allowed better characterization
of the genetic diversity in wheat germplasm. In addition, the molecular cloning of major resistance (R) genes has recently been achieved in the large, polyploid wheat genome. For the first time this allows the study and analysis
of the genetic variability of wheat R loci at the molecular level and therefore, to screen for allelic variation at such loci in the gene pool. Thus, strategies
such as allele mining and ecotilling are now possible for characterization of wheat disease resistance. Here, we discuss the
approaches, resources and potential tools to characterize and utilize the naturally occurring resistance diversity in wheat.
We also report a first step in allele mining, where we characterize the occurrence of known resistance alleles at the wheat
Pm3 powdery mildew resistance locus in a set of 1,320 landraces assembled on the basis of eco-geographical criteria. From known
Pm3 R alleles, only Pm3b was frequently identified (3% of the tested accessions). In the same set of landraces, we found a high frequency of a Pm3 haplotype carrying a susceptible allele of Pm3. This analysis allowed the identification of a set of resistant lines where new potentially functional alleles would be present.
Newly identified resistance alleles will enrich the genetic basis of resistance in breeding programmes and contribute to wheat
improvement. 相似文献