TuMV as an efficient transient vector for expressing heterologous proteins in Nicotiana tabacum and N. benthamiana

Nowadays the production of recombinant proteins such as drugs and commercial protein compounds in plants is called molecular farming. It has some benefits such as fast and large quantity production of recombinant proteins with low cost. In this research, the green fluorescent protein (GFP) was transiently expressed in two tobacco species via turnip mosaic virus (TuMV) derived vector, a virus which can infect a wide range of plant species. Florescence microscopy results indicated that TuMV could infect tobacco plants and accumulate GFP protein in plant leaves. In addition, RT-PCR, Dot-Blot and ELISA assays demonstrated the recombinant gene transcription, translation and stability. This is the first report of using TuMV-based viral vectors for producing recombinant proteins in tobacco. Optimized TuMV-based viral vectors could be used for producing recombinant proteins in tobacco

Studies on the structure and gene expression of barley yellow dwarf virus / by Masoud Shams-Bakhsh.

Bibliography: leaves 118-132.iv, 132 leaves : ill. ; 30 cm.This thesis examines the structure and gene expression of barley yellow dwarf viruses (BYDVs)-PAV in order to gain a better understanding of the interaction between the virus and the Yd2 resistance gene. The protein products of open reading frame (ORF)3, ORF4 and ORF5 are expressed in bacterial cells, in order to characterise the BYDV-PAV virion-associated proteins. The effect of the Yd2 resistance gene on the expression of the BYDV-PAV viral proteins in infected cells is also studied.Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 199

Enhanced resistance and neutralization of defense responses by suppressors of RNA silencing

7 páginas, 5 figuras, 1 tabla -- PAGS nros. 103-109The effects of transgenic expression of the potato virus Y (PVY) HCPro silencing suppressor in tobacco were examined on infection by several viruses. Infection by tobacco mosaic virus (TMV) was reduced at 25 °C, but not at 33 °C. By contrast, systemic infection at 33 °C by the TMV expressing green fluorescent protein was promoted by the HCPro. Infection by tobacco rattle virus (TRV) was restricted to local necrotic lesions by the PVY HCPro. However, this resistance was neutralized by expression of the cucumber mosaic virus (CMV) 2b protein from TRV. By contrast, infection by either wild-type CMV or CMV with a deletion of the 2b gene was not affected. Similarly, infection by cauliflower mosaic virus, red clover necrotic mosaic virus (both limited to infection of the inoculated leaves of tobacco) or tomato bushy stunt virus (systemically infecting tobacco) was not altered by the expression of PVY HCPro. Therefore, it appeared that the PVY HCPro was able to induce defense responses at 25 °C, but not at 33 °C, where it actually neutralized a pre-existing defense response. Moreover, the CMV 2b protein was able to neutralize a defense response activated by HCPro in combination with TRVThis work was supported in part by a cooperative grant from the Korean Rural Development Administration under their BioGreen 21 Program and by the SCRI Innovation FundPeer reviewe

Prevalence and phylogenetic analysis of Fig mosaic virus and Fig badnavirus-1 in Iran

Fig mosaic virus (FMV) and Fig badnavirus-1 (FBV-1) are two of the most important fig infecting viruses. The incidence and distribution of FBV-1 and FMV were determined by testing in PCR 138 asymptomatic and symptomatic samples. These samples were collected from 60 fig gardens and agricultural fields in three provinces of Iran. The fig infecting viruses FBV-1 and FMV, respectively, were detected in 92 (66.6%) and 34 (24.6%) samples collected from all the surveyed fields. Overall, 24 out of 138 (17.3%) samples showed mixed infections. The sequence analysis of a genomic fragment of 922 nt, comprising the entire ORF-2 and part of the 5’ termini of the ORF-3 of 10 selected FBV-1 Iranian isolates from different provinces, and of the type member from GenBank (Acc. No: JF411989), showed a variation ranging from 1 to 3% at nucleotide level and 1% at the amino acid level. The phylogenetic analysis grouped the FBV-1 isolates into two groups, with the Iranian isolates clustered in two distinct subgroups of group I, according to their geographical origin. In our research, the prevalence and sequence analysis of FBV-1 as the only identified DNA virus infecting fig trees, was studied for the first time in Iran

Induction of Resistance in Common Bean by <I>Rhizobium leguminosarum</I> bv. <I>phaseoli</I> and Decrease of Common Bacterial Blight

Rhizobium leguminosarum bv. phaseoli was evaluated for its capacity to trigger resistance to common bacterial blight (CBB) of common bean caused by Xanthomonas axonopodis pv. phaseoli (Xap), under greenhouse and field conditions. A common bean cultivar and three lines including two tolerant lines (Ks51103 and BF13607) and the susceptible cultivar Khomein and line Ks21479, were used. R. leguminosarum bv. phaseoli, was applied as a seed treatment and its effect on disease severity (DS) was compared with untreated (control) plants and with urea fertilizer treated plants in both the greenhouse and the feld. R. leguminosarum bv. phaseoli in common bean roots tended to reduce CBB severity and to improve plant growth, particularly the 100-seed weight, in the field. The greatest decrease in CBB in the greenhouse occurred 15 days after inoculation (DAI) of Xap in the cultivar Khomein and line Ks21479, and 30 DAI in lines Ks51103 and BF13607. In the field, however, the greatest decrease occurred 35 DAI in the cultivar and all lines. Furthermore, in the field the greatest improvement in 100-seed weight occurred in the cultivar Khomein treated with R. leguminosarum bv. phaseoli. The potential of using R. leguminosarum bv. phaseoli in the management of CBB and the possible mechanisms that induce resistance in this symbiotic system are discussed

Identification and expression analysis of a microRNA cluster derived from pre-ribosomal RNA in <i>Papaver somniferum</i> L. and <i>Papaver bracteatum</i> L.

<div><p>Opium poppy (<i>Papaver somniferum</i> L.) is one of the ancient medical crops, which produces several important alkaloids such as morphine, noscapine, sanguinarine and codeine. MicroRNAs are endogenous non-coding RNAs that play important regulatory roles in plant diverse biological processes. Many plant miRNAs are encoded as single transcriptional units, in contrast to animal miRNAs, which are often clustered. Herein, using computational approaches, a total of 22 miRNA precursors were identified, which five of them were located as a clustered in pre-ribosomal RNA. Afterward, the transcript level of the precursor and the mature of clustered miRNAs in two species of the Papaveraceae family, i.e. <i>P</i>. <i>somniferum</i> L. and <i>P</i>. <i>bracteatum</i> L, were quantified by RT-PCR. With respect to obtained results, these clustered miRNAs were expressed differentially in different tissues of these species. Moreover, using target prediction and Gene Ontology (GO)-based on functional classification indicated that these miRNAs might play crucial roles in various biological processes as well as metabolic pathways. In this study, we discovered the clustered miRNA derived from pre-rRNA, which may shed some light on the importance of miRNAs in the plant kingdom.</p></div

Functional Analysis of V2 Protein of Beet Curly Top Iran Virus

Geminivirus beet curly top Iran virus (BCTIV) is one of the main causal agents of the beet curly top disease in Iran and the newly established Becurtovirus genus type species. Although the biological features of known becurtoviruses are similar to those of curtoviruses, they only share a limited sequence identity, and no information is available on the function of their viral genes. In this work, we demonstrate that BCTIV V2, as the curtoviral V2, is also a local silencing suppressor in Nicotiana benthamiana and can delay the systemic silencing spreading, although it cannot block the cell-to-cell movement of the silencing signal to adjacent cells. BCTIV V2 shows the same subcellular localization as curtoviral V2, being detected in the nucleus and perinuclear region, and its ectopic expression from a PVX-derived vector also causes the induction of necrotic lesions in N. benthamiana, such as the ones produced during the HR, both at the local and systemic levels. The results from the infection of N. benthamiana with a V2 BCTIV mutant showed that V2 is required for systemic infection, but not for viral replication, in a local infection. Considering all these results, we can conclude that BCTIV V2 is a functional homologue of curtoviral V2 and plays a crucial role in viral pathogenicity and systemic movement

Schematic representations of cluster miRNAs in pre-rRNA of <i>P</i>. <i>somniferum</i> L. and <i>P</i>. <i>bracteatum</i> L.

<p>ETS: External Transcribed Spacer, ITS: Internal Transcribed Spacer.</p

List of miRNAs identified in two species of <i>P</i>. <i>somniferum</i> L. and <i>P</i>. <i>bracteatum</i> L.

<p>List of miRNAs identified in two species of <i>P</i>. <i>somniferum</i> L. and <i>P</i>. <i>bracteatum</i> L.</p

Some of the putative targets for clustered miRNAs in <i>P</i>. <i>somniferum</i> L.

<p>Some of the putative targets for clustered miRNAs in <i>P</i>. <i>somniferum</i> L.</p