The use of geminiviruses in biotechnology and plant molecular biology, with particular focus on Mastreviruses (original) (raw)
Related papers
Physiologia Plantarum, 2004
Wheat dwarf geminivirus (WDV) is a single-stranded DNA Mastrevirus. The large intergenic region (LIR) of WDV contains cis-acting elements essential for the replication of the genome as well as for the bidirectional transcription of virus genes. The LIR was fused to the GUS (uidA) reporter gene and the WDV viral sense (V-sense) promoter activity derived from the stable integration of that promoter was analysed in transgenic dicot plants. Various dicot species were tested, including Nicotiana tabacum, Nicotiana benthamiana, Arabidopsis thaliana and Cucumis melo. The GUS activity driven by the WDV promoter was also compared to that obtained in plants transformed with the GUS gene controlled by the CaMV 35S promoter as well as two phloem-specific promoters derived from the Arabidopsis thaliana AtSUC2 and AtAHA3 genes. Histochemistry showed that the WDV V-sense promoter consistently induced an expression pattern restricted to the vascular tissues, predominantly in the phloem of all organs. This promoter exhibited levels of GUS activity comparable to that driven by AtSUC2 and AtAHA3 promoters. A vascular expression pattern was observed in the four dicots tested. This was stable during plant development and was not altered following viral infection by an unrelated geminivirus. The uses of such a promoter are discussed regarding the targeting to the phloem of molecules active against vascular pests or pathogens.
Archives of Virology, 2012
Cotton leaf curl Multan betasatellite (CLCuMB) replicates in tobacco, tomato and datura plants in the presence of the helper viruses tomato leaf curl virus-Australia, Iranian isolates of tomato yellow leaf curl virus, tomato leaf curl Karnataka virus, and beet severe curly top virus (BSCTV). Infectious recombinant CLCuMB constructs were made in which segments of either the CaMV 35S or the petunia ChsA promoter replaced the CLCuMB bC1 ORF, and these were designated pBinbDC1-35S and pBinbDC1-ChsA, respectively. Inoculation of tobacco plants containing a functional 35S-GUS transgene with pBinbDC1-35S, and normal petunia plants with pBinbDC1-ChsA, in the presence of helper viruses resulted in silencing of GUS and ChsA activities in transgenic tobacco and non-transgenic petunia plants, respectively. Replication of CLCuMB with different geminiviruses, especially BSCTV, a curtovirus with a broad host range, makes it a valuable gene delivery vector to the large number of host plant species of geminiviruses that support CLCuMB.
Microbial Physiology, 2004
In the past, plant molecular biologists have relied on Escherichia coli, baculovirus and other expression systems to produce plant proteins to quantities sufficient for biochemical analysis. However, such expression systems often result in the production of proteins which possess improper posttranslational modifications. Here, we present a plant virus-based expression system superior to those currently available. We demonstrate that bean yellow dwarf geminivirus (BeYDV) replicates and expresses foreign proteins at high levels in tobacco, Arabidopsis, and other dicotyledonous plants, making it more universal than plant RNA viruses with restricted host ranges which are currently used as expression systems. The DNA-based nature of the BeYDV genome renders it stable for the incorporation of large plant open reading frames, and gives it an advantage over other plant virus-based expression systems which possess insert size restrictions. Using this expression system, the rapid accumulation...
DNA Virus Vectors for Vaccine Production in Plants: Spotlight on Geminiviruses
Plants represent a safe, efficacious and inexpensive production platform by which to provide vaccines and other therapeutic proteins to the world's poor. Plant virus expression vector technology has rapidly become one of the most popular methods to express pharmaceutical proteins in plants. This review discusses several of the state-of-the-art plant expression systems based upon geminiviruses that have been engineered for vaccine production. An overview of the advantages of these small, single-stranded DNA viruses is provided and comparisons are made with other virus expression systems. Advances in the design of several different geminivirus vectors are presented in this review, and examples of vaccines and other biologics generated from each are described.
Plant biotechnology …, 2010
Running title -Protein expression in plants utilising BeYDV Keywords -Geminivirus, BeYDV, replicating plant expression vector Word count -3861 SUMMARY (246 words) We constructed a novel autonomously replicating gene expression shuttle vector, with the aim of developing a system for transiently expressing proteins at levels useful for commercial production of vaccines and other proteins in plants. The vector, pRIC, is based on the mild strain of the geminivirus Bean yellow dwarf virus (BeYDV-m) and is replicationally released into plant cells from a recombinant Agrobacterium tumefaciens Ti plasmid. pRIC differs from most other geminivirusbased vectors in that the BeYDV replication-associated elements were included in cis rather than from a co-transfected plasmid, while the BeYDV capsid and movement protein genes were replaced by an antigen encoding transgene expression cassette derived from the non-replicating A. tumefaciens vector, pTRAc. We tested vector efficacy in Nicotiana benthamiana by comparing transient cytoplasmic expression between pRIC and pTRAc constructs encoding either enhanced green fluorescent protein (EGFP) or the subunit vaccine antigens, Human papillomavirus subtype 16 (HPV-16) major capsid protein L1 and Human immunodeficiency virus subtype C (HIV-1C) p24 antigen. The pRIC constructs
Reprogramming plant gene expression: a prerequisite to geminivirus DNA replication
Molecular Plant Pathology, 2004
Geminiviruses constitute a large family of plant-infecting viruses with small, single-stranded DNA genomes that replicate through double-stranded intermediates. Because of their limited coding capacity, geminiviruses supply only the factors required to initiate their replication and use plant nuclear DNA polymerases to amplify their genomes. Many geminiviruses replicate in differentiated cells that no longer contain detectable levels of host DNA polymerases and associated factors. To overcome this barrier, geminiviruses induce the accumulation of DNA replication machinery in mature plant cells by reprogramming host gene expression. The mammalian DNA tumour viruses activate host genes required for DNA replication by binding to the retinoblastoma protein, a negative regulator of cell cycle progression, and relieving repression through the E2F family of transcription factors. In this review, we discuss recent experiments showing that geminiviruses also modulate components of the retinoblastoma/E2F transcription regulatory network to induce quiescent plant cells to re-enter the cell cycle and regain the capacity to support high levels of DNA replication. Regulation of the cell division cycle and its integration with developmental pathways is complex, with many factors, including hormones, sucrose and environmental signals, controlling reentry into the plant cell cycle. Geminivirus interactions with these regulatory networks are likely to determine if and where they can replicate their genomes in different plant tissues and hosts.