Tomato (Solanum lycopersicum L.), an economically important crop is host to many whitefly transmitted geminiviruses including tomato leaf curl virus (ToLCV). Genetically engineering resistance of pathogen through Post-transcriptional gene silencing (PTGS/RNAi) a powerful strategy that can provide alternative existing methods producing resistant plants. We cloned and characterized ToLCV-replicas...

RNA silencing refers to small regulatory RNA-mediated processes that repress endogenous gene expression and defend hosts from offending viruses. As an anti-host defense mechanism, viruses encode suppressors that can block RNA silencing pathways. Cucumber mosaic virus (CMV)-encoded 2b protein was among the first suppressors identified that could inhibit post-transcriptional gene silencing (PTGS)...

RNA silencing, an evolutionarily conserved and sequence-specific gene-inactivation system, has a pivotal role in antiviral defense in most eukaryotic organisms. In plants, a class of exogenous small RNAs (sRNAs) originating from the infecting virus called virus-derived small interfering RNAs (vsiRNAs) are predominantly responsible for RNA silencing-mediated antiviral immunity. Nowadays, the pro...

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 ca...

The discovery of the post-transcriptional gene silencing (PTGS) by small non-protein-coding RNAs is considered as a major breakthrough in biology. In the last decade we just started to realize the biologic function and complexity of gene regulation by small non-coding RNAs. PTGS is a conserved phenomenon which was observed in various species such as fungi, worms, plants, and mammals. Micro RNAs...

Abstract Tomato yellow leaf curl virus (TYLCV) is known to encode 6 canonical viral proteins. Our recent study revealed that TYLCV also encodes some additional small proteins with potential virulence functions. The fifth ORF of in the complementary sense, which we name C5, evolutionarily conserved, but little about its expression and function during infection. Here, confirmed C5 by analyzing pr...

Research to date indicates that post-transcriptional gene silencing (PTGS) is an effective strategy for the development of stable high-level resistance to Plum pox virus in plum. Field tests in Poland, Romania, and Spain show that after 5–6 years of natural aphid vectored inoculation, trees of the PTGS clone C5 remain virus-free. The effectiveness of transgene-based PTGS for imparting potyvirus...

Double-stranded RNAs can suppress expression of homologous genes through an evolutionarily conserved process named RNA interference (RNAi) or post-transcriptional gene silencing (PTGS). One mechanism underlying silencing is degradation of target mRNAs by an RNP complex, which contains approximately 22 nt of siRNAs as guides to substrate selection. A bidentate nuclease called Dicer has been impl...

Double-stranded (ds) RNA causes the specific degradation of homologous RNAs in a process called "RNA interference (RNAi)"[1-4]; this process is called "posttranscriptional gene silencing (PTGS)" in plants [5-7]. Both classes of gene silencing have been reviewed extensively [8-13]. The duplex RNA becomes processed by Dicer [14] or another RNase III-like enzyme to short dsRNA fragments of about 2...

The intensity of flower colour, mainly determined by the amount of anthocyanin, is an important horticultural trait. To modulate flower colour intensity, post-transcriptional gene silencing (PTGS)-based technology has been widely used. The constraint of PTGS, however, is that it requires a high degree of conservation in the nucleotide sequences of the target and the silencer. Further, it is dif...