scholarly journals Engineering Resistance to Multiple Prunus Fruit Viruses Through Expression of Chimeric Hairpins

2007 ◽  
Vol 132 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Zongrang Liu ◽  
Ralph Scorza ◽  
Jean-Michel Hily ◽  
Simon W. Scott ◽  
Delano James
Keyword(s):  
Gene Silencing ◽  
Mosaic Virus ◽  
Fruit Production ◽  
Cauliflower Mosaic Virus ◽  
Ringspot Virus ◽  
35S Promoter ◽  
Plum Pox Virus ◽  
In Planta ◽  
Posttranscriptional Gene Silencing ◽  
Transgenic Lines

Prunus L. fruit production is seriously affected by several predominant viruses. The development of new cultivars resistant to these viruses is challenging but highly desired by breeders and growers. We report a posttranscriptional gene silencing-based approach for engineering multivirus resistance in plants. A single chimeric transgene, PTRAP6, was created by the fusion of 400 to 500-base pair (bp) gene fragments from six major Prunus fruit viruses, including american plum line pattern virus, peach mosaic virus, plum pox virus (PPV), prune dwarf virus (PDV), prunus necrotic ringspot virus, and tomato ringspot virus (ToRSV). Both strands of PTRAP6 were found being transcribed as an ≈2.5-kilobp transcript in planta without splicing interruption. To induce gene silencing/virus resistance, we placed two copies of PTRAP6 in an inverted repeat under the control of the cauliflower mosaic virus 35S promoter and separated by an intron spacer fragment to create PTRAP6i. Inoculation of the resulting transgenic Nicotiana benthamiana Domin. plants revealed that 12 of 28 R0 PTRAP6i transgenic lines (43%) were resistant to ToRSV ranging from mild symptoms to symptom-free phenotypes. Detailed analysis of two of three highly resistant homozygous R3 generation lines demonstrated that they were resistant to all three viruses tested, including PDV, PPV, and ToRSV. The remaining three viruses targeted by PTRAP6i were either unavailable for this study or were unable to systemically infect N. benthamiana. Transgene-wide and -specific small interfering RNA species were detected along with disappearance of transgene transcript in the resistant lines, indicating that posttranscriptional gene silencing underlies the mechanism of resistance. This work presents evidence that PTRAP6i is able to confer gene silencing-based resistance to multiple Prunus fruit viruses.

scholarly journals Differential Roles of AC2 and AC4 of Cassava Geminiviruses in Mediating Synergism and Suppression of Posttranscriptional Gene Silencing

2004 ◽  
Vol 78 (17) ◽  
pp. 9487-9498 ◽  
Author(s):  
Ramachandran Vanitharani ◽  
Padmanabhan Chellappan ◽  
Justin S. Pita ◽  
Claude M. Fauquet
Keyword(s):  
Gene Silencing ◽  
Mosaic Virus ◽  
Defense Mechanism ◽  
Fluorescent Protein ◽  
Cauliflower Mosaic Virus ◽  
African Cassava Mosaic Virus ◽  
35S Promoter ◽  
Viral Dna ◽  
Posttranscriptional Gene Silencing ◽  
Cassava Mosaic Virus

ABSTRACT Posttranscriptional gene silencing (PTGS) in plants is a natural defense mechanism against virus infection. In mixed infections, virus synergism is proposed to result from suppression of the host defense mechanism by the viruses. Synergistic severe mosaic disease caused by simultaneous infection with isolates of the Cameroon strain of African cassava mosaic virus (ACMV-[CM]) and East African cassava mosaic Cameroon virus (EACMCV) in cassava and tobacco is characterized by a dramatic increase in symptom severity and a severalfold increase in viral-DNA accumulation by both viruses compared to that in singly infected plants. Here, we report that synergism between ACMV-[CM] and EACMCV is a two-way process, as the presence of the DNA-A component of ACMV-[CM] or EACMCV in trans enhanced the accumulation of viral DNA of EACMCV and ACMV-[CM], respectively, in tobacco BY-2 protoplasts. Furthermore, transient expression of ACMV-[CM] AC4 driven by the Cauliflower mosaic virus 35S promoter (p35S-AC4) enhanced EACMCV DNA accumulation by ∼8-fold in protoplasts, while p35S-AC2 of EACMCV enhanced ACMV-[CM] DNA accumulation, also by ∼8-fold. An Agrobacterium-based leaf infiltration assay determined that ACMV-[CM] AC4 and EACMCV AC2, the putative synergistic genes, were able to suppress PTGS induced by green fluorescent protein (GFP) and eliminated the short interfering RNAs associated with PTGS, with a correlated increase in GFP mRNA accumulation. In addition, we have identified AC4 of Sri Lankan cassava mosaic virus and AC2 of Indian cassava mosaic virus as suppressors of PTGS, indicating that geminiviruses evolved differently in regard to interaction with the host. The specific and different roles played by these AC2 and AC4 proteins of cassava geminiviruses in regulating anti-PTGS activity and their relation to synergism are discussed.

scholarly journals T4 Lysozyme and Attacin Genes Enhance Resistance of Transgenic `Galaxy' Apple against Erwinia amylovora

2002 ◽  
Vol 127 (4) ◽  
pp. 515-519 ◽  
Author(s):  
Kisung Ko ◽  
John L. Norelli ◽  
Jean-Paul Reynoird ◽  
Herb S. Aldwinckle ◽  
Susan K. Brown
Keyword(s):  
Mosaic Virus ◽  
Erwinia Amylovora ◽  
Alfalfa Mosaic Virus ◽  
Cauliflower Mosaic Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
35S Promoter ◽  
In Planta ◽  
Mechanical Wounding ◽  
Genes Encoding ◽  
Transgenic Lines

Genes encoding lysozyme (T4L) from T4 bacteriophage and attacin E (attE) from Hyalophora cecropia were used, either singly or in combination, to construct plant binary vectors, pLDB15, p35SAMVT4, and pPin2Att35SAMVT4, respectively, for Agrobacterium-mediated transformation of `Galaxy' apple, to enhance resistance to Erwinia amylovora. In these plasmids, the T4L gene was controlled by the cauliflower mosaic virus 35S promoter with duplicated upstream domain and the untranslated leader sequence of alfalfa mosaic virus RNA 4, and the attE gene was controlled by the potato proteinase inhibitor II (Pin2) promoter. All transgenic lines were screened by polymerase chain reaction (PCR) for T4L and attE genes, and a double-antibody sandwich enzyme-linked immunosorbent assay for neomycin phosphotransferase II. Amplification of T4L and attE genes was observed in reverse transcriptase-PCR, indicating that these genes were transcribed in all tested transgenic lines containing each gene. The attacin protein was detected in all attE transgenic lines. The expression of attE under the Pin2 promoter was constitutive but higher levels of expression were observed after mechanical wounding. Some T4L or attE transgenic lines had significant disease reduction compared to nontransgenic `Galaxy'. However, transgenic lines containing both attE and T4L genes were not significantly more resistant than nontransgenic `Galaxy', indicating that there was no in planta synergy between attE and T4L with respect to resistance to E. amylovora.

Aberrant promoter methylation occurred from multicopy transgene and SU(VAR)3 - 9 homolog 9 (SUVH9) gene in transgenic Nicotiana benthamiana

2012 ◽  
Vol 39 (9) ◽  
pp. 764 ◽  
Author(s):  
Gi-Ho Lee ◽  
Seong-Han Sohn ◽  
Eun-Young Park ◽  
Young-Doo Park
Keyword(s):  
Gene Silencing ◽  
Nicotiana Benthamiana ◽  
Fluorescent Protein ◽  
Cauliflower Mosaic Virus ◽  
Camv 35S Promoter ◽  
35S Promoter ◽  
Camv 35S ◽  
Histone Deacetylase 1 ◽  
Transgenic Lines ◽  
Green Fluorescent

The chemical modification of DNA by methylation is a heritable trait and can be subsequently reversed without altering the original DNA sequence. Methylation can reduce or silence gene expression and is a component of a host’s defence response to foreign nucleic acids. In our study, we employed a plant transformation strategy using Nicotiana benthamiana Domin to study the heritable stability of the introduced transgenes. Through the introduction of the cauliflower mosaic virus (CaMV) 35S promoter and the green fluorescent protein (GFP) reporter gene, we demonstrated that this introduced promoter often triggers a homology-dependent gene-silencing (HDGS) response. These spontaneous transgene-silencing phenomena are due to methylation of the CaMV 35S promoter CAAT box during transgenic plant growth. This process is catalysed by SU(VAR)3–9 homologue 9 (SUVH9), histone deacetylase 1 (HDA1) and domains rearranged methylase 2 (DRM2). In particular, we showed from our data that SUVH9 is the key regulator of methylation activity in epigenetically silenced GFP transgenic lines; therefore, our findings demonstrate that an introduced viral promoter and transgene can be subject to a homology-dependent gene-silencing mechanism that can downregulate its expression and negatively influence the heritable stability of the transgene.

scholarly journals Development and Use of an Efficient DNA-Based Viral Gene Silencing Vector for Soybean

2009 ◽  
Vol 22 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Chunquan Zhang ◽  
Chunling Yang ◽  
Steven A. Whitham ◽  
John H. Hill
Keyword(s):  
Virus Infection ◽  
Gene Silencing ◽  
Functional Genomics ◽  
Mosaic Virus ◽  
Soybean Mosaic Virus ◽  
Cauliflower Mosaic Virus ◽  
Viral Gene ◽  
35S Promoter ◽  
Virus Induced Gene Silencing ◽  
Wide Range

Virus-induced gene silencing (VIGS) is increasingly being used as a reverse genetics tool to study functions of specific plant genes. It is especially useful for plants, such as soybean, that are recalcitrant to transformation. Previously, Bean pod mottle virus (BPMV) was shown to be an effective VIGS vector for soybean. However, the reported BPMV vector requires in vitro RNA transcription and inoculation, which is not reliable or amenable to high-throughput applications. To increase the efficiency of the BPMV vector for soybean functional genomics, a DNA-based version was developed. Reported here is the construction of a Cauliflower mosaic virus 35S promoter-driven BPMV vector that is efficient for the study of soybean gene function. The selection of a mild rather than a severe BPMV strain greatly reduced the symptom interference caused by virus infection. The DNA-based BPMV vector was used to silence soybean homologues of genes involved in plant defense, translation, and the cytoskeleton in shoots and in roots. VIGS of the Actin gene resulted in reduced numbers of Soybean mosaic virus infection foci. The results demonstrate the utility of this new vector as an efficient tool for a wide range of applications for soybean functional genomics.

scholarly journals Expression of thaumatin, a new type of alternative sweetener in rice

2020 ◽  
Vol 48 (3) ◽  
pp. 1276-1291
Author(s):  
Shahina AKTER ◽  
Md. Amdadul HUQ ◽  
Yu-Jin JUNG ◽  
Kwon-Kyoo KANG
Keyword(s):  
Transgenic Rice ◽  
Oryza Sativa L ◽  
Plasmid Vector ◽  
Single Copy ◽  
Cauliflower Mosaic Virus ◽  
Pcr Analysis ◽  
35S Promoter ◽  
Alternative Sweetener ◽  
Sweet Proteins ◽  
Transgenic Lines

  Sweet proteins are the natural alternative to the artificial sweeteners as well as flavor enhancers. Among other sweet protein, thaumatin protein was isolated from Thaumatococcus daniellii Benth plant fruit. In this study, pinII Ti plasmid vector was constructed with thaumatin gene, where thaumatin was placed under the control of the duel cauliflower mosaic virus 35S promoter into rice (Oryza sativa L. var. japonica cv. ‘Dongjinbyeo’) by Agrobacterium-mediated transformation to generate transgenic plants. Thirteen plant lines were regenerated and the transgenic rice lines were confirmed by different molecular analysis. The genomic PCR result revealed that all of the plant lines were transgenic. The single copy and intergenic plant lines were selected by Taqman PCR analysis and FST analysis, respectively. Expression of thaumatin gene in transgenic rice resulted in the accumulation of thaumatin protein in the leave. Thaumatin protein was also accumulated in leave of T1 generation. Sensory analysis result suggested that the thaumatin protein expressing transgenic lines exerted sweet tasting activity. These results demonstrated that thaumatin was expressed in transgenic rice plants.

scholarly journals Quantification of the 35S Promoter in DNA Extracts from Genetically Modified Organisms Using Real-Time Polymerase Chain Reaction and Specificity Assessment on Various Genetically Modified Organisms, Part I: Operating Procedure

2005 ◽  
Vol 88 (2) ◽  
pp. 547-557 ◽  
Author(s):  
Sophie Fernandez ◽  
Chrystèle Charles-Delobel ◽  
Angèle Geldreich ◽  
Georges Berthier ◽  
Francine Boyer ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Real Time ◽  
Genetically Modified Organisms ◽  
Limit Of Detection ◽  
Genetically Modified ◽  
Collaborative Study ◽  
Cauliflower Mosaic Virus ◽  
Performance Criteria ◽  
35S Promoter ◽  
Conserved Sequence

Abstract A highly sensitive quantitative real-time assay targeted on the 35S promoter of a commercial genetically modified organism (GMO) was characterized (sF/sR primers) and developed for an ABI Prism® 7700 Sequence Detection System and TaqMan® chemistry. The specificity assessment and performance criteria of sF/sR assay were compared to other P35S-targeted published assays. sF/sR primers amplified a 79 base pair DNA sequence located in a part of P35S that is highly conserved among many caulimovirus strains, i.e., this consensus part of CaMV P35S is likely to be present in many GM events. According to the experimental conditions, the absolute limit of detection for Bt176 corn was estimated between 0.2 and 2 copies of equivalent genome (CEG). The limit of quantification was reached below 0.1% Bt176 content. A Cauliflower Mosaic Virus control (CaMV) qualitative assay targeted on the ORF III of the viral genome was also used as a control (primers 3F/3R) to assess the presence of CaMV in plant-derived products. The specificity of this test was assessed on various CaMV strains, including the Figwort Mosaic Virus (FMV) and solanaceous CaMV strains. Considering the performance of sF/sR quantification test, the highly conserved sequence, and the small size of the amplicon, this assay was tested in a collaborative study in order to be proposed as an international standard.

Functional analysis of cauliflower mosaic virus 35S promoter: re-evaluation of the role of subdomains B5, B4 and B2 in promoter activity

2007 ◽  
Vol 5 (6) ◽  
pp. 696-708 ◽  
Author(s):  
Simran Bhullar ◽  
Sudipta Datta ◽  
Sonia Advani ◽  
Suma Chakravarthy ◽  
Taru Gautam ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Mosaic Virus ◽  
Promoter Activity ◽  
Cauliflower Mosaic Virus ◽  
35S Promoter ◽  
Cauliflower Mosaic Virus 35S

scholarly journals Introgression of a Tombusvirus Resistance Locus from Nicotiana edwardsonii var. Columbia to N. clevelandii

2006 ◽  
Vol 96 (5) ◽  
pp. 453-459 ◽  
Author(s):  
James E. Schoelz ◽  
B. Elizabeth Wiggins ◽  
William M. Wintermantel ◽  
Kathleen Ross
Keyword(s):  
Mosaic Virus ◽  
Resistance Genes ◽  
Virus Resistance ◽  
Dominant Gene ◽  
Cauliflower Mosaic Virus ◽  
Ringspot Virus ◽  
N Gene ◽  
Interspecific Crosses ◽  
Addition Line ◽  
Resistance Locus

A new variety of Nicotiana, N. edwardsonii var. Columbia, was evaluated for its capacity to serve as a new source for virus resistance genes. Columbia was developed from a hybridization between N. glutinosa and N. clevelandii, the same parents used for the formation of the original N. edwardsonii. However, in contrast to the original N. edwardsonii, crosses between Columbia and either of its parents are fertile. Thus, the inheritance of virus resistance genes present in N. glutinosa could be characterized by using Columbia as a bridge plant in crosses with the susceptible parent, N. clevelandii. To determine how virus resistance genes would segregate in interspecific crosses between Columbia and N. clevelandii, we followed the fate of the N gene, a single dominant gene that specifies resistance to Tobacco mosaic virus (TMV). Our genetic evidence indicated that the entire chromosome containing the N gene was introgressed into N. clevelandii to create an addition line, designated N. clevelandii line 19. Although line 19 was homozygous for resistance to TMV, it remained susceptible to Tomato bushy stunt virus (TBSV) and Cauliflower mosaic virus (CaMV) strain W260, indicating that resistance to these viruses must reside on other N. glutinosa chromosomes. We also developed a second addition line, N. clevelandii line 36, which was homozygous for resistance to TBSV. Line 36 was susceptible to TMV and CaMV strain W260, but was resistant to other tombusviruses, including Cucumber necrosis virus, Cymbidium ringspot virus, Lettuce necrotic stunt virus, and Carnation Italian ringspot virus.

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