scholarly journals Transgenic Plants Expressing Geminivirus Movement Proteins: Abnormal Phenotypes and Delayed Infection by Tomato mottle virus in Transgenic Tomatoes Expressing the Bean dwarf mosaic virus BV1 or BC1 Proteins

2000 ◽  
Vol 13 (3) ◽  
pp. 297-308 ◽  
Author(s):  
Yu-Ming Hou ◽  
Rick Sanders ◽  
Virgina M. Ursin ◽  
Robert L. Gilbertson

Transgenic tomato plants expressing wild-type or mutated BV1 or BC1 movement proteins from Bean dwarf mosaic virus (BDMV) were generated and examined for phenotypic effects and resistance to Tomato mottle virus (ToMoV). Fewer transgenic plants were recovered with the wild-type or mutated BC1 genes, compared with the wild-type or mutated BV1 genes. Transgenic tomato plants expressing the wild-type or mutated BV1 proteins appeared normal. Interestingly, although BDMV induces only a symptomless infection in tomato (i.e., BDMV is not well adapted to tomato), transgenic tomato plants expressing the BDMV BC1 protein showed a viral disease-like phenotype (i.e., stunted growth, and leaf mottling, curling, and distortion). This suggests that the symptomless phenotype of BDMV in tomato is not due to a host-specific defect in the BC1 protein. One transgenic line expressing the BC1 gene did not show the viral disease-like phenotype. This was associated with a deletion in the 3′ region of the gene, which resulted in expression of a truncated BC1 protein. Several R0 plants, expressing either wild-type or mutated BV1 or BC1 proteins, showed a significant delay in ToMoV infection, compared with non-transformed plants. R1 progeny plants also showed a significant delay in ToMoV infection, but this delay was less than that in the R0 parents. These results also demonstrate that expression of viral movement proteins, in transgenic plants, can have deleterious effects on various aspects of plant development.

1994 ◽  
Vol 119 (3) ◽  
pp. 642-647 ◽  
Author(s):  
P.B. McGarvey ◽  
M.S. Montasser ◽  
J.M. Kaper

Transgenic tomato plants (Lycopersicon esculentum Mill.) expressing cucumber mosaic virus (CMV) satellite RNA fused to a gene for β-glucuronidase were produced using Agrobacterium-mediated transformation. The R1 progeny of self-crossed R0 plants were challenge-inoculated with virion or RNA preparations of CMV or tomato aspermy virus (TAV). The transgenic plants challenged with CMV-1 showed mild disease symptoms in the first 2 weeks postchallenge followed by a decrease in symptoms, resulting in little difference between the transgenic and uninfected control group by the fourth week. Enzyme-linked immunosorbent assay results showed about a 10-fold decrease in virus accumulation in the transgenic plants compared to controls. Tolerance was evident only in plants that contained the recombinant insert and produced mature unit-length satellite RNA after CMV infection. Plants challenged with TAV showed no significant tolerance to virus-induced symptoms.


Author(s):  
A.A. ANTONOV ◽  
◽  
E.N. BARANOVA ◽  
A.A. GULEVICH ◽  
L.V. KURENINA ◽  
...  

The change in the composition of soil microbiota as a result of the cultivation of various crops in agrocenoses is currently of great interest. The authors studied the effect of the root system of transgenic tomato plants (Solanum lycopersicum L.) grown in soil culture on the microbial community in the rhizosphere. The results showed that as a result of the cultivation of transgenic plants with the choline oxidase gene, the microbial community composition in the rhizosphere has changed significantly. A significant increase in the proportion (73%) and species diversity (Shannon index 2.25) of actinobacteria in the soil root zone of tomato transgenic codA plants as compared with control plants (10% and 0.95, respectively) has been revealed. The content of pseudomonads and micromycetes is significantly reduced (25 and 12% in transgenic plants; 70 and 81% in control plants, respectively). Thus, genetically modified plants are able to influence the microbial community structure in the rhizosphere.


2014 ◽  
Vol 27 (10) ◽  
pp. 1159-1169 ◽  
Author(s):  
Laura Campos ◽  
Purificación Lisón ◽  
María Pilar López-Gresa ◽  
Ismael Rodrigo ◽  
Laura Zacarés ◽  
...  

Hydroxycinnamic acid amides (HCAA) are secondary metabolites involved in plant development and defense that have been widely reported throughout the plant kingdom. These phenolics show antioxidant, antiviral, antibacterial, and antifungal activities. Hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) is the key enzyme in HCAA synthesis and is induced in response to pathogen infection, wounding, or elicitor treatments, preceding HCAA accumulation. We have engineered transgenic tomato plants overexpressing tomato THT. These plants displayed an enhanced THT gene expression in leaves as compared with wild type (WT) plants. Consequently, leaves of THT-overexpressing plants showed a higher constitutive accumulation of the amide coumaroyltyramine (CT). Similar results were found in flowers and fruits. Moreover, feruloyltyramine (FT) also accumulated in these tissues, being present at higher levels in transgenic plants. Accumulation of CT, FT and octopamine, and noradrenaline HCAA in response to Pseudomonas syringae pv. tomato infection was higher in transgenic plants than in the WT plants. Transgenic plants showed an enhanced resistance to the bacterial infection. In addition, this HCAA accumulation was accompanied by an increase in salicylic acid levels and pathogenesis-related gene induction. Taken together, these results suggest that HCAA may play an important role in the defense of tomato plants against P. syringae infection.


2002 ◽  
Vol 52 (3) ◽  
pp. 219-223 ◽  
Author(s):  
Tsukasa Nunome ◽  
Fumiyoshi Fukumoto ◽  
Fumihiro Terami ◽  
Kaoru Hanada ◽  
Masashi Hirai

HortScience ◽  
2015 ◽  
Vol 50 (6) ◽  
pp. 789-796 ◽  
Author(s):  
An Qin ◽  
Xiaosan Huang ◽  
Huping Zhang ◽  
Juyou Wu ◽  
Jie Yang ◽  
...  

Ascorbic acid (AsA) is a major antioxidant and redox buffer in plants. Dehydroascorbate reductase (DHAR; EC 1.8.5.1) catalyzes the conversion of dehydroascorbate (DHA) to AsA and is crucial for AsA regeneration. In this study, we developed transgenic tomato plants that overexpressed PbDHAR2 to investigate whether PbDHAR2 could limit the deleterious effects of salt and chilling stresses. These transgenic plants contained significantly higher AsA levels than the wild-type (WT) plants. Overexpression of PbDHAR2 increased the expression of the AsA-glutathione (GSH) cycle genes in transgenic lines under salt and chilling stresses. In addition, the transgenic lines subjected to salt and chilling stresses showed higher levels of antioxidant enzyme activity, lower malondialdehyde (MDA) levels, and higher chlorophyll contents than the WT. Thus, our results demonstrate that the regulation of PbDHAR2 during AsA regeneration contributes to enhanced salt and chilling tolerance in tomato.


1988 ◽  
Vol 6 (4) ◽  
pp. 403-409 ◽  
Author(s):  
Richard S. Nelson ◽  
Sheila M. McCormick ◽  
Xavier Delannay ◽  
Philip Dubé ◽  
Jeanne Layton ◽  
...  

Plant Omics ◽  
2021 ◽  
pp. 1-10
Author(s):  
Ghada Ahmed Abu El-Heba

Tomato (Lycopersicon esculentum) is the main vegetal crop that has tremendous popularity around the world. Medicago truncatula NOOT gene (Mt-NOOT) encodes a BTB/POZ-ankyrin repeat protein of the NONEXPRESSOR OF PR GENES1 (NPR1 family). It was introduced into Lycopersicon esculentum (Tomato) genome. The tomato plants that ectopically expressed Mt-NOOT obtained several favorable traits and fruit quality. Heteroblasty between the transgenic and the non-transgenic tomato leaves and flower architecture were used to distinguish transgenic and wild lines. Transgenic tomato plants accumulated a significant amount of phenolic compounds and plant pigmentations compared to the wild type. On the other hand, transgenic plants acquired a considerable amount of antioxidant such as CuZnSO superoxide dismutase (SOD), tomato Catalase (CAT), and tomato Cell wall-associated peroxidase (TPX1) than the wild type. Antioxidant high content together with the high content of phenolic compounds enabled the transgenic tomato fruits to gain not only edible benefits, but also a significant higher shelf-time, extended to six months more than the wild type stored at 25°C in dark and dry condition. Surprisingly, transgenic tomato fruits did not show any rotten process during long time storage as they did not acquire any contagious microorganism. Total fruit productivity in transgenic tomato was greater than the control with an estimated ratio of 84%.


1998 ◽  
Vol 11 (6) ◽  
pp. 498-503 ◽  
Author(s):  
Hans Weber ◽  
Artur J. P. Pfitzner

The Tm-22 resistance gene is used in most commercial tomato cultivars for protection against infection with tomato mosaic virus (ToMV). It has been suggested that Tm-22 resistance interferes with viral cell-to-cell movement in plants; ToMV strain ToMV-22 requires two amino acid (aa) exchanges in the carboxy-terminal region of the viral 30-kDa movement protein (at positions 238 and 244) to overcome Tm-22 resistance. For further analysis of this region of the 30-kDa protein, two stop codons were introduced into ToMV movement proteins at aa positions 235 and 237, leading to deletion of the terminal 30 aa. The mutant virus strains were able to infect wild-type tomato plants systemically, suggesting the carboxy-terminal portion of the ToMV 30-kDa protein is dispensable for virus transport in tomato. Even more important, the deletion mutants overcame the Tm-22 resistance gene. These data indicate the carboxy-terminal domain of the ToMV movement protein serves as a recognition target in the context of the Tm-22 resistance gene. Furthermore, expression of the 30-kDa movement protein from wild-type ToMV, but not from ToMV-22, in transgenic tomato plants with the Tm-22 resistance gene led to elicitation of a necrotic reaction in tomato seedlings, showing that the 30-kDa protein on its own is able to induce the plant's defense reaction.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 569c-569
Author(s):  
John R. Stommel ◽  
Marie E. Tousignant ◽  
Thanda Wai ◽  
Jacobus M. Kaper

Viral satellite RNA associated with cucumber mosaic virus (CMV) is know to modulate CMV symptomology. Virulent CMV associated RNA 5 (CARNA 5) satellites may intensify crop disease. Naturally occurring variants of these satellites, however, attenuate CMV symptoms. Satellite transgenic tomato plants expressing the S-CARNA 5 or 1-CARNA 5 ameliorating forms of the satellite were evaluated under simulated CMV epidemic conditions in USDA–APHIS approved field trials. Trials conducted at Beltsville, Md., in 1994 and 1995 demonstrated that CMV can be effectively controlled under field conditions in satellite transgenic plants. Yields of transgenic lines infected with CMV were 50%–65% greater than that of non-transgenic infected controls. Yields of noninfected transgenic lines ranged from 5% greater than, to 33% less than, noninfected nontransgenic controls. Expression of CARNA 5 in inoculated transgenic plants greatly reduced CMV foliar symptoms and virus titers when compared to inoculated control plants. Levels of CARNA 5 were detected at varying levels in infected transgenic plants throughout the growing season. Virus or satellite was not detected in samples collected from tomato border plants and weeds growing inside and outside a nonhost crop border surrounding the test plot. Field tests conducted in 1996 will evaluate transgenic tomato plants with a double construct coding for the CMV coat protein gene and 1-CARNA 5 satellite.


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